on June 24, 2005
Why should you get this charger instead of some other charger?
5 words: CHARGE, DISCHARGE, TEST, REFRESH and LCD!
Choose the individual charging rate for each battery, (200/500/700/1000/1500*/1800*mA).
Why choose the charging rate?
If you're rushing, charge fast and hot. If you're charging overnight or over dinner, charge more slowly. Slow charging is almost always gentler on the batteries, giving you a longer useful life.
Why set the charging rate individually?
You want this ability in case you have batteries of different capacities, partially discharged batteries, mixed brand/quality or any number of other reasons.
1500/1800mAh only available in Charge mode and only when charging 1 or 2 batteries in terminals 1 and/or 4.
This mode discharges the battery down to 1 volt then recharges to full capacity using Delta V measurement, at a user-selectable charging level*, of course.
Why discharge then charge?
This is the older technique developed to avoid capacity-robbing memory effect encountered when recharging NiCad-based batteries (which by the way are compatible with this charger, unlike the Maha mentioned below).
Why Delta V?
This is the modern measurement adopted by most "fast/rapid" chargers. While not quite as accurate as simultaneously using Temperature measurement and/or detecting Zero Delta V, as the Maha/PowerEx C-204W can do, it should be enough to prevent battery damage and insure complete, consistent charging.
Discharge rates are 1/2 the selected charging rate (max 1000mAh charging in this and other modes). Some batteries can take discharge rates this high, others can't. Most electronics don't drain batteries this fast continuously, so most batteries won't be any "healthier" if discharged too fast. Since this mode will probably take several hours to complete, do it overnight at the gentler 200mAh or 500mAh charging modes (and corresponding 100mAh/250mAh discharge modes).
Did you think that those little power strips on alkaline batteries were a good idea? I did, who doesn't want to know how much juice is left in a battery. The problem is the indicator bars weren't very meaningful and couldn't measure voltage too accurately.
Now, this charger can tell you more accurately the voltage output of your batteries (which you may interpret as an indication if it's fully charged > 1.40V or discharged < 1.20V). Still, that's just an indication of charged capacity. Why not a direct measurement?
The Test mode does just that. It measures the capacity of each battery and reports it. It initially charges each battery, discharges it (simultaneously measuring the mAh) and then recharges it, leaving you with full batteries and a record of how much juice it discharged during the test.
You ever pull open a drawer, find a rechargeable, wonder if it's "still any good," recharge it and then use it just to find out? This baby will do it all for you, giving you the answer for each battery as it finishes.
Another good reason is to verify the capacity of newly bought batteries. I'm using it now to check each battery in a brand 24-pack of Lenmar 2000s. It's found some clunkers which I'm saving for the next mode, which is...
If you're thinking this mode refreshes batteries, you're right. I haven't had the chance to use it yet, but you know I will. I've got some great candidates too, brand new clunkers from Lenmar, some good old "state of the art 1400mAh" Sanyo and Nexcell NiMH's and even some older NiCads (it may be cheaper in the short term to return them to service than to dispose of them).
You can't use this charger on alkalines or rechargeable alkalines, so don't even think about "refreshing" those in this charger.
One thing about the Refresh mode. Refreshing NiCads manually may take several cycles of charging and discharging. Not only does this charger perform the charge/discharge cycle as many as 20 times, it measures the capacity of each discharge cycle and stops refreshing when the capacity of each battery isn't improving anymore. With other chargers, you're probably overcharging some of the batteries just to get the others back up to snuff.
One thing the Maha doesn't have is an LCD readout (though their C-777 model does, maybe next year?). The BC-900 has an individual LCD readout for each battery, which you can set to alternatively display any of 4 different measurements (hours, volts, mA charge/discharge, mAh), in addition to continuous displaying the particular mode each battery is in. The LCD readout retains it's reading (e.g. tested mAh) until the battery is pulled out, making overnight "tests" possible. The LCD makes all the other charger modes informative and practical.
Shame on those other chargers that have LCD indicator bars but no numerical display (some even cost more than the BC-900).
Understand, as great as all the different modes and options of this charger are, without an informative LCD display, they would be "shot's in the dark". With the individual displays, I'm happily recharging batteries, checking the quality of each, refreshing some while storing the "truly" fully charged ones.
With the LCD, I'm getting an idea of just how good a pack of batteries (and hence brand) is.
ROOM FOR IMPROVEMENT
The current power brick is oriented so that it may block adjacent outlets, so put it on the end of a powerstrip or AVR/UPS unit. My Nokia phone charger has the plugs on the edge so it's really low profile on the outlet.
While the transformer is thankfully a bit slimmer than most external units, it is also a bit longer than most (about 1.75in by 3). It is however Autovolt from 100-240V, although another reviewer mentioned the 3V DC output was sort of a pain.
I wish this charger had a built-in power transformer and a retractable cord.
Batteries get hot from charging, they'll read hot too. A built-in cooling fan would keep the batteries cooler during charging and probably give a more accurate "just-charged" reading on the LCDs. Some other high end chargers have fans built-in, so I'd hate to see this "ultimate" charger get upstaged by lacking such a common-sense $1 feature.
The unit comes with a free bag which is much roomier than necessary. I could fit my Casio Exilim camera, dock & transformer for the Casio, backup compact film camera along with the battery charger, C/D-cell adapters and 24-pack of batteries in the bag. While I feel sort of silly mentioning a quirk about a free item, the bag is hardly usable as a belt bag since it is so ... baggy.
If you ever invest in rechargeable AA/AAA technology, you'll multiply your investment by getting this charger.
I've REFRESHed about 8 clunkers so far, 2 NiCads an officemate brought for me to work on (about 2 years old) and 6 Lenmar 2000 batteries.
1 rated at 700, first TESTed at 256, REFRESHed to 677.
2 rated at 700, first TESTed at 344, REFRESHed to 741.
NIMH - done REFRESHing.
1 rated at 2000, first TESTed at 448, REFRESHed to 1507.
2 rated at 2000, first TESTed at 527, REFRESHed to 1820.
3 rated at 2000, first TESTed at 680, REFRESHed to 1488.
NIMH - still REFRESHing.
4 rated at 2000, first TESTed at 435, REFRESHed to 1270+.
5 rated at 2000, first TESTed at 436, REFRESHed to 1713+.
6 rated at 2000, first TESTed at 349, REFRESHed to 1813+.
More Room for Improvement?
Charging Rate Limit (wrt Terminal 1)
The charging rate selected for Terminal 1 (1-4 left to right) is the highest rate you can select for each of the 4 Terminals. I didn't think this would be a big deal, but when you REFRESH batteries at the gentlest rate (200mah charging, 100mah discharging) and the cycle may repeat as many as 20 times ... well, you do the math. I know I didn't have to set it at the gentlest rate, but I figured I shouldn't stress already marginal batteries.
Now, when the battery in Terminal 2 read full (as in Fully Refreshed), I took it out to charge one of the other batteries I had already used up. Enter the Charging Rate Limit. I am limited to 200mah charging (the current setting for the still REFRESHing battery in Terminal 1) and it's driving me nuts! I wish each Terminal had it's full 200-1000mah charging rate available independent of the settings on the other Terminals.
[IMPORTANT NOTICE on Jan 5, 2010]
My old BC-900 has served me well for the past 4 years. But recenetly there is an inrush of reports on 'meltdown' of the new BC-9009. I can only assume that La Crosse is having very poor quality control with the new model. My advice is to stay away from BC-9009 for now, until the situation has been rectified.
[Update on Apr 15, 2010]
The BC-9009 is available through Amazon again. But of course it will take a few more weeks before we can be sure if the overheating problem has been fixed. If any brave soul decide to order one to try out, I encourage you to exercise the charger fully (Refresh at the 1A current setting) for a few days, and watch for any signs of overheating (such as hot-spot on the base of the charger). Make sure to let us know the outcome.
[Update on Jan 22, 2011]
If you have purchased the BC-9009 recently, make sure it has the latest firmware version '37' (this number appears briefly in the rightmost column when you first plug in the AC adapter). Several users have reported that they have no overheating problems with this new version, even though the AC adapter has the same 'IV' marking.
[Original review follows]
I have a La Crosse Technology BC-900 AlphaPower Battery Charger since nearly two years ago, and I'm very happy with it. When the Maha Powerex MH-C9000 WizardOne Charger-Analyzer was announced, its looked even better on paper than the BC-900. So I also bought the C9000 one month ago. Here is my assessment for those two chargers:
First, let's get the similarities out of the way. Both the BC-900 and the C9000 are powerful battery analyzers/conditioners which can also be used as your everyday battery chargers. Both chargers accept one to four AA or AAA cells with independent charging currents. Both come with universal (100-240V AC) adapter.
Next, the differences:
First thing you'll notice is that the Maha C9000 is HUGE for a 4-AA-cell charger. It is about twice as large as the BC-900 (see my Customer Image for size comparison).
Larger size makes the C9000 less suitable as a travel charger. However, as a home charger this is actually an advantage. Extra spacing between cells allows better cooling, and also makes it easier to remove individual cell.
2. CHARGING CURRENT:
The BC-900 can provide charging current from 200 to 1000mA for 4 cells, or up to 1800mA for two cells. The C9000 can charge from 200 to 2000mA for all four cells. So if you routinely need to charge cells in a hurry, the C9000 is better.
However, due to the complicated key sequences involved (for example, to charge 4 cells at 2000mA, you need to punch in 48 key strokes!), most sane people will probably leave the C9000 at its default current of 1000mA.
The BC-900 has a 4-column LCD panel that shows the status (capacity, voltage, current, or time) of all four cells either simultaneously, or individually. The C9000 sports a LCD display with back-light. It is BIG, it is BRIGHT, and it works really well - as a NIGHT LIGHT!
The biggest problem with the C9000's display is that it can only show one status for one cell at any one time. It constantly toggles from one status to another, then from one cell to the next. If you have 4 cells in the charger, it takes 48 seconds or more (depending on the current activity) for the display to cycle through all 4 cells. There is also no way to pause the display. So if you missed one reading, you have to wait for it to cycle through again.
4. ANALYZING / CONDITIONING FUNCTIONS:
The BC-900 has an easy-to-use 'DISCHARGE/REFRESH' function that can be used to recondition old cells. The C9000 has a similar function called 'CYCLE', but it is very tedious to use (see the USER INTERFACE section for details).
In addition, the C9000 also has a 'BREAK-IN' mode which supposedly should be applied to new cells before first use, or to really old cells that have not been charged for years. Beware that this operation takes at least 39 hours to complete, so I doubt many people would actually use it.
5. DEAD CELL DETECTION:
If a cell is completely drained (battery terminal voltage drops below 0.5V), the BC-900 thinks it is shorted and therefore refuses to charge it. This has caused a lot of frustrations among users, but there is a way to work around it (see my BC-900 Customer Image for details). The C9000 is smarter in this aspect. If the battery terminal voltage is too low, it automatically starts charging at 125mA until the voltage rises above 1V, then it continues with the programmed charging current.
The C9000 also measures battery internal resistance when a cell is first inserted. If the user inserts an alkaline cell (which has much higher internal resistance), the C9000 displays 'HIGH' and refuses to charge it. This is a good safety feature, except that it also incorrectly rejected most of my NiMH cells bought four or five years ago. So I cannot use the C9000 to charge or recondition those old cells, even though the BC-900 reports that they still have around 1000mAh of capacity left.
6. USER INTERFACE:
With the BC-900, you can select the operation and current for all cells simultaneously, or you can change them indivdually by using the cell-selection buttons. The only limitation is that once the charging current is fixed, you cannot subsequently select a larger current without removing all cells.
The C9000 has four completely independent charging circuits that can be programmed to different currents. This may sound great at first, but in practice it soon becomes a burden, because you often need to press dozens of key stokes to program all four cells.
For example: If you want to recondition four cells on the BC-900, you'll go through the following sequence:
- insert in all 4 cells at once
- press MODE to select DISCHARGE/REFRESH (2 keystrokes*)
- press CURRENT to select charging current (2-3 keystrokes)
* Note: need to press and hold MODE for ~3 seconds for the first keystroke
On the C9000, you can insert in all 4 cells at once, but you have to program them one at a time. Which means:
- press UP/DOWN to select 'CYCLE', then 'ENTER' (2-5 key strokes)
- press UP/DOWN to select charging current, ENTER (1-11 key strokes)
- press UP/DOWN to select discharging current, ENTER (1-6 key strokes)
- press UP/DOWN to select number of cycles, ENTER (1-13 key strokes)
Congratulations! You just finished programming the first cell. Now repeat that for the other three cells.
The Maha MH-C9000 is, without a doubt, the most powerful NiMH AA battery analyzer/charger in the consumer market. However, certain design issues (such as a single-status LCD panel and ridiculously long programming sequences) make it difficult to use for multiple cells. For most of my routine charging and maintenance of NiMH cells, I'll continue to use my old La Crosse BC-900.
Nevertheless, I don't regret buying the C9000, because it was a lot of fun for me to try out all its functions. Plus I now have a really cool (but expensive) night light.
Ni-MH batteries have become ubiquitous over the past decade. Their low cost and ever-increasing capacity make them a great alternative to alkaline batteries. Of course, you need to keep these batteries charged... And that's where things get complicated.
Charging Ni-MH batteries is the result of a compromise. A low current is gentle on the battery and maximizes its lifespan, but a full charge takes hours.
A high current will recharge the battery much faster, but put more strain on it, causing it to wear out prematurely. It also requires careful monitoring of the battery's electrical characteristics to prevent damage.
Most of the chargers you can find on the market today use one or the other of these methods. The fast chargers, especially the cheap ones, excel at one thing: destroying perfectly good batteries, because they lack the monitoring circuitry to control the charge current and detect when the battery is full. The slow chargers are usually better, mainly because it's harder to design a really bad slow charger. Unfortunately... they're slow.
The BC-900 is a completely different breed: it lets you pick the charge current for each individual battery, has very sophisticated monitoring circuitry that controls the charging process, and is also capable of "renewing" batteries by running full controlled discharge-recharge cycles.
I was a little skeptical that a fairly inexpensive product would be so thorough, but after reading all the 5-star reviews on Amazon I decided to give it a try. I'm glad I did: it's all it's cracked up to be, and more. I ran all my AA and AAA batteries through it; some of them had been destroyed by my previous charger, and it weeded those out right away; some were in pretty bad shape, but a refresh brought them back to life at almost full capacity.
The pleasant surprise was to find out all the freebies that come with the charger: four AA and four AAA batteries to get you started, four C-cell adapters, four D-cell adapters, and a nifty carrying case.
The less pleasant surprise: it can take several days to refresh batteries. I suppose this explains why the box didn't contain a cigarette lighter car adapter. Also, different batteries will take a different amount of time to complete a similar charging cycle. The charging slots being individually powered and monitored, it's not a real issue, since you can yank out any cell that's finished charging and insert the next one that needs recharging as soon as the little LCD screen warns you it's done.
As far as I know this is the best charger you can buy. It's reliable, gentle on the batteries, has useful capabilities not found on other models, and comes with a lot of extras. It's more expensive than your ordinary cheap slow charger, but the increased battery lifespan more than makes up for the price difference.
on February 19, 2007
I must say that I thought all chargers were more or less the same. After purchasing a myriad of chargers and batteries I now realize that the various batteries and chargers make all kinds of silly claims that rarely meet expectations. I use AA NiMH batteries for some electronic devices (mice, radios, etc.) and my two Canon cameras. Since my S2 and S3 cameras have a healthy appetite for batteries I decided to check out some reviews and buy from Thomas-Distributing. They are an excellent, if pricey, source for rechargable batteries and chargers. The array of choices is dizzying. I now own two LaCrosse BC-900s that I purchase from Amazon at a much better price. Thomas-Distributing also sells the full line of Maha chargers that seem to garner top ratings but I think the Maha model that is similar to the LaCrosse, costs more and offers fewer features. I own two lower-end Maha chargers and I think they are great. But, the flexibility and information offered by LaCrosse makes this model the best and quite possibly the only charger for AA/AAA batteries that you will ever need. The AC adapter is external and adds bulk so this charger is perhaps less compact than those all-in-one plug in the wall types. But the features built into this model make this my absolute favorite. Other chargers require that you charge two batteries together and the LaCrosse allows you to charge up to four batteries independently at separate rates using separate functions. This is important if you have different batteries with different capacities. The display allows you to monitor each battery for current/time/voltage/capacity side by side. This way you can refresh one battery while discharging one battery while charging one battery... you get the idea. Unlike the Maha model, the display shows all four battery status levels side by side. No scrolling through menus for each battery one by one. At a glance you can check each battery and compare it to the next battery. Most chargers from department stores or camera shops are designed to rapidly charge the battery within a few hours. The high current does charge more quickly but generates heat and reduces the effective life of the battery. Furthermore, those blinking lights don't have accurate meters so you have no information about the true capacity and no idea about the condition of your batteries. Some chargers have a conditioning button which discharges and recharges but still does not give any accurate information. The LaCrosse lets you charge, discharge, measure, recondition and effectively revive batteries. I usually use the lowest default current and refresh my batteries over one week. This takes time but brings my batteries to full capacity. The maH capacity of the battery printed on the battery is often overstated so here is your chance to compare the brands of batteries. (I think the Powerex and Sanyo batteries from Thomas-Distributing are the best.) If you are in a big hurry simply choose a higher current and rapidly charge your batteries. Did you know that any device using multiple batteries will have a battery life limited by the battery with the lowest capacity? Let me explain, If you have four AA batteries that state 2400 maH capacity each, if one battery is weaker than the true 2400 mah (lets just say 1800 maH) then the combination of all four batteries in your device will function to a capacity of only 1800 maH. I'll illustrate... bought four expensive 2400 maH batteries and found that they would run out faster than my old 1800 maH batteries! Using the LaCrosse I discovered that one battery had a capacity of only 1500 maH and the other three were about 2200 maH. I refreshed all four and they all exceed 2500 maH now! Now I take several hundred photos on a single set of batteries. After purchasing eight chargers and throwing away most of them, it's clear that this is the one charger that really shines. It will save you money by reviving old batteries. The price is great and the charger comes with a set of AA and AAA batteries. The included battery adapters may come in handy in an emergency if you need C batteries for a flashlight or toy. My only complaint is the external AC adapter which makes it less portable; I think this is really a minor quibble. If you prefer a rapid charger without all these features check out Maha. Hope this helps.
on November 22, 2007
This is in response to Eric Olstad's review on Oct 10, 2007...
"I was hoping that it would be able to detect how much power is currently in the battery, but it doesn't."
You don't mean power, you mean current capacity. And, yes, the BC-900 can determine this, but it, or any other charger/analyzer, cannot just "determine" remaining current capacity with the wave of a magic wand. The analyzer must discharge the cell at a user-set rate of current, and it calculates the current capacity based upon the discharge current and how long it took to discharge.
"It just detects the heat coming from the batteries and that's how it knows how not to overcharge."
Wrong, wrong, wrong. The BC-900 terminates charge primarily by sensing the slight drop in voltage which occurs just as the cell becomes fully charged. It is state of the art detection. In addition, there are two other ways in which the BC-900 will terminate, and they are both safety features in case you are trying to charge bad cells which may not provide sufficient voltage drop at end-of-charge. First, there are indeed heat sensors under the cells: one under cells 1 & 2, and another under cells 3 & 4. Under normal operation, the ECU does not terminate charge based upon these because under normal operation (good cells, not charging at too-high a rate for the cells capacity) the cells do not get hot enough for these sensors to tell the ECU to stop the show. Only if something goes out of bounds and the cells heat above 127 degrees Fahrenheit will the temperature sensors come into play and halt charging. If this happens, the charger stops charging and the charging current display will suddenly show "000 mA". This occurs in pairs, that is, if cell 1 and/or 2 overheats, current is shut down to both cells 1 & 2. Likewise, if cell 3 and/or 4 overheats, the current to bay's 3 & 4 shuts down. Only one cell in the pair must overheat to trigger charge cessation to both. I have verified this with a non-contact IR thermometer while charging four low capacity cells at too-high a rate. This is the only feature on the BC-900 which is not truly independent across all four channels. Once the current shuts down to the cells, they begin to cool. Once safely below the trigger temperature, the current will ramp back up over the course of about two seconds and you are back in action charging away again. But if you have triggered the over-temp safety feature by charging at too-high a rate, it will just shut back down again a while later after the cells heat up again, so it makes more sense to heed what the charger is trying to tell you("000 mA") and reduce the charge current.
The second fail-safe feature is a maximum current limit. Some cells, especially older, neglected NiMH charged at low rates (200 mA) may not provide sufficient end-of-charge voltage drop for the ECU to halt charging, but at such slow charge rates neither will the cells become overly warm, so the temperature sensor will not tell the ECU to shut things down either. In this scenario, the charger will stop charging after it has put a maximum amount of current into the cell, the upper limit of which is set by La Crosse. I have forgotten the figure. Nonetheless, given such redundancy, I find it hard to imagine how one could "expect a little more from this product!"
I own two V.33 and one V.32 of the BC-900. Obviously, I am a fan, but I would like to voice a couple gripes I have with the unit. First, someone mentioned their unit freezing up. Both software versions can occasionally freeze up (most notably just as the fourth and final cell terminates), or the ECU may suddenly disallow certain user input, necessitating a hard reset (which is just unplugging and plugging back in). It can be a pain if you are a day or two into a refresh and it occurs, causing you to lose your capacity data. It does not happen very often, but often enough for me that I did some research and found a cure. It seems the problem can be tracked to noise in the provided power supply. The solution (not to be performed by your average consumer) is to solder special filter capacitors across the inputs on the circuit board. I have done this to all three of my BC-900's and have not had a single incident of ECU freezing in several months since. Again, the freezing is not terribly frequent, but buyers should be aware that if it does occur on their unit that it is pretty much "normal" when using the included power supply.
Another gripe, pretty much universal, is that the button operation is marginal. Sometimes you can push a button and nothing happens. A firmer-than-should-be necessary push is needed. What is more frustrating is some of my buttons will occasionally "bounce." That is, you push the button once, but the display cycles through two functions instead of just the next one. La Crosse really could have sourced better switches for probably no more cost.
Another gripe that may or may not come into play for some users is how the unit holds the "maximum accumulated capacity" in memory. If you use the "refresh" feature, the cell will be discharged as the accumulated discharge capacity is shown on the display. When the cell is completely discharged, it will begin to charge back up, but while doing so it will hold the maximum discharge capacity in the display all throughout the charge and second discharge. At the end of the second discharge, the first maximum accumulated capacity display will be replaced by the value determined in the second discharge.
Stay with me, here. Sometimes it is very useful to know simply how much capacity a cell has without having to put a cell through multiple refresh cycles. One would think to use the "discharge" function, which will discharge the cell while showing the accumulated discharge capacity, then recharge the cell. Where La Crosse really dropped the ball is that as soon as the cell discharges completely and begins to charge back up, the accumulated discharge capacity is erased from the display and the "accumulated charge" is displayed. "Accumulated charge" is a worthless piece of information which means nothing. La Crosse should have arranged for the maximum discharge capacity to be held in the display during the "discharge" mode just as in the "refresh" mode. Of course, you can just do one-half cycle in refesh mode, but then you have to make sure you babysit the charger in order to catch the maximum discharge capacity displayed during recharge, but halt the cycle manually before it begins the second discharge. Depending on the charge/discharge rates you selected, this window can be as brief as an hour or less before it begins to discharge again.
Most likely any BC-900's sold today are V.33. The learning curve to discover and master all the programming features of the BC-900 can be a little steep for some. When you select your desired mode and current settings, the display will hold this value for several seconds in case you change your mind and want to select another mode or current setting, then sensing no additional input, the display will flash once and begin the cycle. While getting up to speed on learning my V.32 BC-900, sometimes the display would flash once and begin the cycle before I had time to figure out what to do next, or figure out where I was while reading the next step in the manual. Well, I think this was a point of contention and frustration for many, so with V.33 La Crosse has exactly doubled the amount of time which passes before the display will flash and begin the cycle: 8 seconds for V.33, up from 4 seconds for the V.32. This is great when you are teething on the unit. But once you are up to speed, you understand the modes and what they do, and in what order they are acccessed by each button push, this doubled delay then becomes excruciatingly long, especially when you want to insert and program four cells with different charging modes and parameters! You have to insert the first cell, manually select it's charging bay, select the parameters, and then wait... and wait... and seemingly wait some more... until the display finally flashes once and the cycle begins for that cell. Then you have to start it all over again with the second cell, and so forth. Once you are up to speed, and you begin programming the unit for multiple modes, this really becomes a tiresome hinderance. Note that V.33 units with the 8 second delay are and/or were shipped with V.32 user manuals which still specify a 4 second delay.
One parting thought... some believe, as I did, that cooling the batteries while charging is doing them a favor. I installed a muffin cooling fan above my chargers for this purpose. Problem is, I quickly found out that by not allowing the cells to heat up at end-of-charge, termination was being missed very often. I would see the cell voltage rise to 1.50 - 1.54 volts (a normal range for termination) and then just hang there indefinitely, never terminating charge. Within 1-2 minutes of turning the cooling fan off, all four cells would terminate in quick succession. This was repeatable to the point of not possibly being a coincidence. The moral is, if you must use a cooling fan, do not use it during the final stages of charging. Once you see around 1.45 volts, shut the cooling fan off. If you can't be present to monitor the voltage, it is better to just leave the fan off altogether, because if the charger misses termination and you continually dump near an ampere of current into already-charged cells, your cells will croak prematurely.
I do monitor impending termination if using the fan, and I also recommend using a fan during "discharge" mode, or the discharge cycle of the "refresh" or "test" modes if discharging multiple cells at higher discharge rates. This is because when the cells are discharging, they create a lot of heat inside the cramped enclosure, and it can get very hot underneath, which can only lead to a shortened life span of the charger. La Crosse has designed some ventilation slots on the under side of the unit, but then they made the four little "teats" on the bottom less than 1/8" high, allowing for basically no convection airflow from bottom to top to keep the cells cool. I purchased four self-adhesive rubber feet that are about 3/8" high and mounted them near the stock teats. This allows for some real convection to get started, and when combined with the fan, the guts of the charger barely get warm now. At the very least, toss a couple pencils under your unit, and you'll double the height the unit sits above the table. If you do not use a fan (as most will not) then it is that much more important to provide this increased clearance, as convection will be your only source of cooling.
Currently Amazon has the BC-900 on sale again with free shipping, and everything mentioned above notwithstanding, it's still all I can do to not click that "Add to Cart" button and make it an even four BC-900's sitting on my shelf in the laundry room!
on October 20, 2005
I would like to give this item 5 stars because it is well made and does a real good job of charging the batteries. But it tends to be temperamental. I had some batterys that were really dead and it would not attempt to charge them. It just said they were null. I put them in my other charger and they did fine in there. But there were some batteries that really were null, that I would not know about if it had not told me.
The other problem is that it is a little difficult to figure out how to use. The default setting is fine and maybe that is all most people will ever need. But the instructions are not really adequate, and the print in them is very small.
Still, this maybe the best charger out there right now. I would stay away from the cheap chargers for two reasons. They do not know if a battery is any good or not. Often in four batteries only one is bad and it is nice to be able to identify the trouble maker. The second problem with the cheap chargers is they do not detect very well. They do not know for sure if your battery even needs charged. So they can burn up your batteries.
This is what happens. You have one battery that is bad. You do not know that and assume your batteries need recharged. The good batteries then get over charged which shortens the life on them and the bad battery will not take a charge. But you really don't know what the problem is because the cheap chargers do not tell you that there is a problem. This charger says NULL, so you know you have a problem with a battery. If it is able to solve that problem, I still don't know. But it is nice just to know which batteries are the trouble makers so you can set them aside and not allow them to get in the way.
Weeding out the bad batteries makes this unit a worthwhile investment. I am sure it will hold up good also.
on June 28, 2011
I bought this unit in March 2011 having read most of the reviews and comments regarding the overheating. My assumption was that the issue had been taken care of with the new adapter. Wrong! After charging beautifully for the past three months I went to retrieve some batteries, only to find the charger actually melted and built up so much heat that the batteries came apart and one was actually venting gas when I went to take them off. I had a Maha charger for over four years that finally bit the dust but never like this. I would stay far away from this defective product.
on October 2, 2006
I've had a BC-900 for a little over a year. I love its capabilities. It was a 5 star until now. I don't know what version it is, it is not shown on the unit itself. Two weeks ago it completely fried a set of 4 AA NiMH. They were bubbling hot. The BC-900 is melted in the center section. Scary. Seemed close to being on fire or exploding the batteries. I'd like to get another one but the fire hazard is scaring me away. BTW, I called LaCrosse Tech Support and the woman I talked with said she was not aware of any such problems with it. Huh???
Update - The original BC-900 has history of this, google it. Shortly after this, about Nov 2006, I called LaCrosse back and requested a new unit. I sent in old one and got back totally new retail package from them. It has worked good since then (now June 2009). I don't remember the version number of the first one but the second unit had a different number. LaCrosse never admitted to me they knew anything about BC-900s self destructing. But plenty of evidence that many people had problems.
on February 28, 2008
Today, after a few months of light use the Lacrosse BC-900 charger caused a major meltdown. Fortunately, I caught it in time before it started a fire, it had heated the 4 eneloop AA batteries so hot they scalded my finger and I quickley unplugged the wire from the back and used a back of a plastic comb to pry the frying hot batteries. The 4 LCD's were still reading 200 after nearly a day, usually it switches off and they say full, after an overnight charge. I would stay away from Lacrosse after this scary experience.
on February 26, 2005
The La Crosse BC-900 is an intelligent battery charger for 1 to 4 AA or AAA batteries at a time. Each channel is independant of the others, and you can mix battery sizes and functions in each channel independantly.
The charger has 4 modes. Charging mode is the default, but it also has a discharge mode, test mode (discharges, then charges back up again, and shows capacity of the battery), or refresh mode (repeats the test mode up to 20 times, until it doesnt see an improvement in the test result).
Each charging channel has an LCD readout that can show the charging current, the voltage of the cell, the capacity of the cell (in ma if under 2.0 amps, or in amps if it is a 2000ma cell or higher) in test or recharge mode, or the time it has been performing the function it is currently doing. It is the readouts which make this charger exceptional! It can help you identify under-performing batteries, and makes it easy to match cells by the actual battery capacity, not a guess just because the batteries were from the same package.
You can charge batteries at different charging rates, ranging from 200ma up to 1.8a. You can be charging at different rates in each channel, but just need to keep in mind that the charging rate you choose in channel 1 will be the maximum charging rate on any other channel. Keep in mind that while you do have control over the charge rate, if you charge at too high of a value, the cells can heat up quite a bit. The unit does have thermal shutoff to protect the cells, but heat can damage nimh cells. The default rate is 200ma which is a gentle charge rate even for AAA cells, but if you are using AA batteries, you will probably choose a higher charge rate.
If you choose the discharge, test, or refresh functions, you can choose the discharge rate. With the test and refresh functions, the discharge rate will always be 1/2 of the charging rate. It will discharge the battery down until the voltage of the cell reaches 1 volt. In test and refresh functions, it will then charge the battery back to full capacity.
The charger also comes with a canvas bag containing 4 AA 2000ma cells, 4 AAA 700ma cells, and 4 battery adapters which allow you to use AA batteries to power C or D cell devices. It makes a handy carrying case for the charger, extra batteries, and a camera, film and accessories. You can sling the strap across your shoulder, or use the belt loop to carry it on your belt.