La Crosse Technology BC-700 Alpha Power Battery Charger

by La Crosse Technology

• Battery charger for NiCad and NiMH AA and AAA rechargeable batteries
• Features 4 modes: charge, discharge, refresh, and test
• Charges both AA & AAA rechargeable batteries simultaneously
• 4 separate LCD displays for simultaneous readouts
• Overheat-detection to prevent over-charging

Product Details

• Product Dimensions: 2 x 3 x 5 inches ; 9.3 ounces
• Shipping Weight: 12.8 ounces (View shipping rates and policies)
• Shipping: This item is also available for shipping to select countries outside the U.S.
• Origin: Made in USA or Imported
• ASIN: B000RSOV50
• Item model number: BC700-CBP
• Average Customer Review: 4.4 out of 5 stars  See all reviews (800 customer reviews)
• Amazon Best Sellers Rank: #331 in Home & Kitchen (See Top 100 in Home & Kitchen)
  • #3 in Electronics > Accessories & Supplies > Camera & Photo Accessories > Batteries & Chargers > Battery Chargers
  • #38 in Electronics > Accessories & Supplies > Batteries, Chargers & Accessories

Product Description

The La Crosse Technology BC700 Alpha Power Battery Charger has four modes and charges all NiCd and NiMH AA and AAA rechargeable batteries. The four modes include charge, discharge (discharges the batteries and then recharges them), recharge (discharges and recharges up to 20 times to bring old batteries back to life) and test (displays the battery capacity). BC-700 Battery Charger " Features: • All modes automatically default to 200 mA charge on the BC-700 Battery charger • Charge both AA and AAA rechargeable batteries simultaneously and will charge all Low-Discharge batteries. Sanyo Eneloop, Uniross Hybrio, Nexcell EnergyOn, Accupower Acculoop and other future low discharge batteries. • Hhas Four independent channels - Charges 1, 2, 3 , or 4 rechargeable batteries at a time. • Overheat detection to protect over-charging and LCD shows capacity for each battery when charging is complete • Charge Mode - allows a range of user selectable milliamp settings from 200 to 700 for faster charging times. Within 4 seconds after rechargeable batteries are inserted charging automatically begins at 200mA, or you may select 500, or 700mA charge rates for faster charging times. • Discharge Mode - reduces memory effect by discharging rechargeable battery completely before recharging to full capacity. User selectable. • Refresh Mode - discharges and recharges up to 20 cycles or until rechargeable battery is refreshed to full capacity. User Selectable. • Test Mode- First charges the rechargeable battery to full capacity, then discharges completely to measure rechargeable battery capacity for display in mAh or Ah, and then recharges each rechargeable battery to full battery capacity. • UL approved, BC 700 charger also has safeguards that sense rechargeable battery polarity, rechargeable battery temperature and defective rechargeable batteries. • World Voltage capable - Operates on 100~240V AC Input.

Most Helpful Customer Reviews

1,359 of 1,387 people found the following review helpful

5.0 out of 5 stars BC-700/900/1000 FAQ August 30, 2007

By NLee the Engineer HALL OF FAMETOP 10 REVIEWER

[Update on April 4, 2012]
My original review was written back in August 2007. Now, nearly 5 years later, most of its content is no longer current. So I will use this spot for publishing my "Frequently Asked Questions" relating to BC-700/900/1000 family of chargers. This list is work in progress and will grow with time. Let me know if you have new questions to be added. Here goes...

[Q1] There are four operation modes on the BC-700 (Charge, Discharge, Test and Refresh). Which mode should I use and when?
[A] Most of the time you just need CHARGE mode. That means put in the batteries and select the charging current desired (500/700mA, etc)
- If you want to know how much capacity your batteries can actually hold, use the CHARGE/TEST function. Be careful not to run this operation if the batteries are freshly charged (doing so may lead to over-charging).
- If you want to find out the remaining charge in a battery, run DISCHARGE/REFRESH and record the 'mAh' number at the end of the first discharge.
- If you suspect your batteries suffer from reduced capacity, run the DISCHARGE/REFRESH operation. Or you can use this mode to refresh your batteries once every 6 months or so. Don't over do it!

[Q2] Why won't the MODE button response when I press it?
[A] Press and hold the MODE button for 3 seconds, then toggle it to change mode.

[Q3] What is the difference between TEST and REFRESH?
[A] TEST starts with a full recharge, then it discharges the cell once to determine its capacity. Next it recharges the cell to full again.
REFRESH starts with a discharge to determine the cell's remaining charge capacity, then it charges the cells back up and drain it down again to determine its new capacity.... It wil repeat this Charge/Discharge cycle multiple times until the capacity stops improving. Finally it charges the cell in the end.

[Q4] My BC-700 has been discharging and refreshing for 3 days!! When does it stop?
[A] The REFRESH operation takes at least three Discharge/Recharge cycles to complete. If you use the default 100mA discharging (200mA charging) current for a 2000mAh AA cell, each Discharge/Recharge cycle takes about 30 hours! Terminate the Refresh operation and restart it using 350mA discharging (700mA charging) instead.

[Q5] What is the best charging current for recharging AA or AAA batteries?
[A] For AAA cells the default 200mA is just right. If you're in a hurry, increase the current to 500mA.
For AA cells you should increase the charging current to either 500mA or 700mA. This reduces the charge time and, more importantly, ensure that the charger will not miss charge termination signal and ends up over-charging your cells.

[Q6] How does the BC-700 know when to stop charging?
[A] The primary termination mechanism is "negative delta-voltage detection" (-dV/dt). If this signal is missed, backup mechanism include: high voltage termination, over-temperature shutdown, and safety timer (stops when total charge > 3700mAh)

[Q7] I ran a Charge/Test operation but in the end it shows a capacity reading of "000 mAh". Are my batteries dead?
[A] Most likely the charger missed the -dV/dt termination signal, and subsequently tripped either over-voltage or over-temperature shutdown.

[Q8] I used the BC-700 to recharge my Duracell 2650mAh batteries, and the capacity readings are over 3000mAh. Are those batteries great or my charger is bad?
[A] When you use CHARGE, the 'mAh' reading is for amount of charge going INTO the battery, not what is actually STORED by the batteries. Because the energy conversion is not 100%, you always need to put in more charge, especially if your batteries are old or leaky. To find out the charge stored, use either Charge/Test, or Discharge/Refresh

[Q9] I put in a set of exhausted batteries and one of them shows 'null'. Is the battery dead?
[A] If a battery has been over-discharged, its terminal voltage may fall below 0.5V and the BC-700 cannot detect it. You can kick-start it by using my "Paper Clip trick" (see customer image section for details), or by charging the dead cell in a dumb charger for a few minutes. Then the BC-700 will recognize it.

[Q10] Why can't I tell how much charge is left in my battery instantly?
[A] No battery testers in this world can do that. The only reliable way is to run Discharge/Refresh. However, you can estimate the `fullness' of your battery by looking at its voltage. When you first insert in a battery, its voltage is displayed for 8 seconds. If the voltage is higher than 1.30V, the battery is mostly full and you don't need to recharge it. If it is below 1.20V, it is nearly exhausted.

[Q11] How do I power the BC-700/1000 from my car battery?
[A] You need a CLA (cigarette lighter adapter) with 3V output at a 2.1/5.0mm barrel jack; current rating of 3A for the BC-700, 4A for the BC-1000. Foer example: AccuPower AP12243 Car Adapter. An easier solution is to get the La Crosse BC500 which runs off 12V directly.

[Q12] What is the REAL advantage of having an advanced charger like the BC-700?
[A] It allows you to determine the true capacity of all your batteries, and to revive those under-performing cells. Then you can group cells with similar capacities together for best result. Plus it looks cool and is a chick-magnet... just kidding!

[Q13] Is it normal for noise to come out from my BC1000 when it is charging batteries?
[A] Yes. The BC-700/1000 uses pulsed charging current at 25% 1 Hz. So when you set the current to 700mA, internally it is putting out 2800mA for 1/4 second. That's why it emits a faint ticking sound once every second.

[Q14] Why am I not able to see a charge termination even at 500 mA charge rate on my brand new AA Eneloops? (Voltage on the battery was 1.43 V when I manually pulled out. When I insert the same battery again it promptly says full!)
[A] It is normal for eneloop cells to reach at least 1.48V just before the delta-voltage drop is detected. If you remove a cell while it is only 1.43V and re-insert it right back, the charger detects a higher than expected voltage for NiMH cell, so it treats the cell as full and will not recharge it. Otherwise it could miss the delta-V detection from this stage.

[Q15] What is "charge rate" and how does it relate to charge time?
- Charge rate C = charging current (mA) / Capacity (mAh)
- Charge time (hr) = Capacity (mAh) / Current (mA) = 1/C
Therefore 0.2C means a charge time of 5 hours, for example

[Q16] What is the best charge rate?
[A] The general recommendation from battery manufacturers is to keep the charge rate between 0.5C and 1C. Higher charge rate shortens battery lifespan. Lower charge rate may cause charger to miss termination signal. In practice, a rate between 0.25C and 0.5C is preferred if pulse-charging technique is used.

[Q17] If I recharge an 800mAh AAA battery at 200mA, is there a danger of missing charge termination signal at 0.25C?
[A] No. The BC-700/900/1000 uses pulsed current at 25% duty cycle. So when you select '200mA', the actual charging current is 800mA for 0.25 second, followed by 0mA for 0.75 second. Therefore although the DC heating effect is at 0.25C, the charge termination signal is determined at 1C. On the other hand, charging a 2000mAh AA cell at 200mA is borderline too low and should be avoided.

[Q18] I have some old batteries that developed high internal resistance. Will it help by cycling those batteries in REFRESH mode?
[A] The problem with higher internal impedance cannot be reversed. Your best hope is to charge them at the slowest rate, then use them for less demanding appliances such as wireless keyboards. But if they also suffer from rapid self-discharge problem, then you should just recycle them.

[Q19] How do I find out the firmware version of my charger?
[A] When you first connect the charger to AC adapter, the rightmost column shows the firmware number. For example, '35' means firmware v35.

[Q20] How does the AccuPower IQ-328 Battery Charger compare to the BC-700/1000?
[A] Except for some very minor differences, the IQ-328 is identical to the BC1000, down to the same bugs. See details here: http://www.amazon.com/review/R1W62S0X09QMMQ/

[Q21] Is the BM200 Battery Charger Analyzer Tester same as the BC1000?
[A] The BM200 has a similar looking LCD panel, but offers many improvements over the BC1000. Read me review on it for details.

===============
Original Review titled "Handicapped version of BC900" follows:
===============
Just in case you were looking for the La Crosse Technology BC-900 AlphaPower Battery Charger: please be advised that ths is NOT the same charger.

Except for the color, the BC700 looks exactly the same as the better-known BC900. However, it is actually a "handicapped" version of the old charger. Its charging current can only go up to 700mA in three steps (200/500/700). The BC900, on the other hand, can go up to 1000mA for 4 cells, or 1800mA for 2 cells. Also the BC900 package includes eight NiMH rechargeable cells (4 AA and 4 AAA), eight C/D cell adaptors, and a carrying case. The BC700 does not come with any bonus items.

This is not to say that the BC700 is a bad product. Quite the contrary, it is better than any other NiMH AA chargers in the market except for BC900 and Maha MH-C9000. If you can find it at a substantial saving (like maybe 30% off from the price of BC900), it is still a good buy. But as it is right now, I recommend getting its older brother instead.

[update on June 13, 2008]
Recently the price of BC700 has settled to a level much lower than that of BC900 (partially because the price of BC900 has gone up), so it is now an excellent buy - especially if you intend to buy some low-self-discharge NiMH cells separately. In light of this, the criticism in my original review now seems unnecessarily harsh. Read more ›

374 of 380 people found the following review helpful

5.0 out of 5 stars Best charger I ever owned April 28, 2008

By Nuknuk TOP 100 REVIEWER

Amazon Verified Purchase

UPDATE: (08-12-2012) It has been 5 years since I wrote this review. This charger is still working great!

I have owned at least 8 chargers in the past, Maha's, Panasonic, etc. It is nice to see that this charger shows you the mAh on the LCD panel as the battery charges up. Most chargers you only see an LED indicator to signal when charging is done.

Compared to the specs of BC-900, the BC700 can only go up to 700mA (the max) which means it is somewhat slower than the BC900. But the faster the battery charges, the hotter it gets. And one of the worst enemy of rechargeable batteries is heat. Less heat means longer life for the batteries.

Pros:
- 3 adjustable charging speeds
- Will show you the actual capacity in mAh. This is good so you know which battery needs to be refreshed. You always want to use batteries with the same capacities in pair or in a group.
- 4 independent charging stations with individual LED readouts. "AA's" and "AAA's" can be charged in different combinations. Don't you hate those gadgets that only use 3 batteries like portable radios? (walkie-talkies). You end up with 1 un-used battery if you bought a 4-pack. How will you charge it if your charger only charges in pairs?
- Reasonable price for an excellent charger
- Small and light. Better portability
- Multi-volt up to 240v. Very useful if you travel a lot to other countries.

Cons:

Now I have to stop myself doing impulse buying on NiMh's because I enjoy using this charger too much.

135 of 151 people found the following review helpful

1.0 out of 5 stars 700 vs WizardOne March 10, 2010

By Romeo Dog

Amazon Verified Purchase

I own both the Lacrosse BC-700 and the Maha WizardOne chargers. The Wizard is larger and it spaces the batteries nicely for cooling and the lighted display, very bright and large, is all-informative. I don't mind that the display toggles between cells, rather than displaying the information on all cells at once. This is my main at-home charger. I keep the Lacrosse at work. More compact in size, the Lacrosse's unlit LCD display is also smaller than the Wizard's but it also is very informative. The BC-700 charges at 200, 500 and 700 Ma, while the Wizard can charge much faster if needed. Frankly, most of the time, I charge at a low 200 Ma on either the Lacrosse or the Wizard for the benefit of longer battery life. The Lacrosse is cheaper and a little more compact, but if you need faster charging (higher than 700 Ma) then the Wizard will fill the bill.

October 2010 update: The Lacrosse now has developed a bad habit of undercharging batteries placed in charger bay #4. Even though the display indicates that all the batteries are fully charged, if one toggles to the accumulated charge screen, it shows that the battery in bay #4 is only half-charged. Sure enough, when I charge that battery again, it will take another half charge to fill it. I now have to do this each time I charge batteries--always have to replace the fourth battery in another bay and continue to charge it for about 6 more hours. This works, but is very frustrating. I would not purchase the Lacrosse again.

December 2010 update: The Lacrosse 700 now is totally unreliable. Several charging bays are indicating full prematurely. I now put batteries back in and watch the 700 continue to charge for hours after it initially displayed "full." Even then I can't trust its readings.... I have replaced it in my office with a GP charger--I don't get all the readouts, but it does the job. This after perhaps charging only one set a batteries a week for less than a year with the Lacrosse. Sad. Meanwhile, back at home my Maha Wizard One is humming away charging batteries with no problems whatsoever. That is one great charger and worth the extra expense! Read more ›