Customer Reviews

Energizer CHVCWB2 Overnight NiMH AA/AAA Charger With 2 2000mAh AA Batteries

5 star:		(4)
4 star:		(4)
3 star:		(0)
2 star:		(3)
1 star:		(12)

 

 

The light comes on when it's charging, but never goes off, so you never know when it's done. Also, you have to charge 2 or 4 at a time, not one or three. Seems to work OK.

It is not clear enough from the earlier reviews -- This charger DOES NOT automatically shut off when the batteries reach full charge. It just keeps cooking them, and they do get quite hot. Can't be very good for them....

I don't have this specific model of charger (I have CHVCM with the same green lights), but I want to give some input on overcharging. It is only safe to leave NiMH batteries charging indefinitely if the charging current is less than 10% of the cell's current rating (The mAh rating.) If the charging current is higher, then you definitely do not want to leave the batteries charging past full charge.

To calculate the charging time, just divide the battery's mAh rating by the charging current output by the charger (measured in mA.) I couldn't find a spec sheet on this charger, so you'll have to flip it over and look at the writing on the back or sides. It will be around the other electrical specifications (AC input voltage and DC output voltage ratings.)

My charger lists the charging current as: 260 to 300mA (~15% of cell's rating). So with 2000mAh batteries, that's an average charging time of about 7 hours. Of course, chargers and batteries vary, so I would let it run a little longer. (My spec sheet reads 8.5hrs for 2000mAh and 10.5hrs for 2450mAh. It also says that there is an 11 hour shutoff timer. Nice!)

You don't need to be totally paranoid about how long you let the charge go, but it does need your attention. Going by the math above, I don't think you'd run into any trouble if you let the charge run for 10 hours, but I would be nervous to let it run for 15 hours. If you want to let it run overnight, but are worried of charging too long, just use a simple AC lamp timer to decide how long to run the charge while you're sleeping. You can pick one up for $10 or less.

That being said, you may be able to charge the suckers for 24 hours without starting a fire or causing the batteries to explode (but maybe not), but it would definitely hurt the battery's ability to hold a charge.

This is a good inexpensive trickle charger. My only quibble has been expressed once before. The green led lights come on as soon as the unit is plugged in. I guess this is to let the user know the socket isn't dead or something??? It doesn't change color or go off. You just have to charge by the suggested times for the specific mAh.

Indeed, like the others said, there is NO WAY to know when the batteries are fully charged because the green light stays on forever. This is wrong.
I am not even sure if this charger actually stops charging when the batteries are full. If not, this means it is a serious hazard.

Works great for the price,Overnight charging is no problem for me and unlike a couple of reviews I read it fits the electrical outlet fine.I got the 2300 mAH batteries so they last pretty well in my camera

Do not buy this product. It doesn't stay in the outlet (falls out) and therefore won't charge your batteries. I returned it back to Energizer and they wrote back saying "thank you for bringing this to our attention" and they didn't even have to fix anything. They knew that something was wrong with it.

I'm sure some of the others from Energizer work, but not this one.

Yes, there are some features and wuality issues here that you probably wouldn't find on a more expensive model: There's no indicator light to singal when your batteries are fully charged. I just leave it on for 12 hours (overnight). You can also look up the suggested amount of time.

And, yes, it's not an immediate fit in your wall socket, but this is not at all an insurmountable problem. You just have to work with the excessive play a little until it stays in place. It's prone to falling out if someone bumps into it. With this in mind, however, I have not had problems other than a slight taxing of my patience.

Bottom line: If you just need to recharge once in a while, and you want to save some money, get this. If you want to pay a few extra bucks for a little more quality, you'll probably want to look around, For me, and others whose demands are similar to mine, this unit works and meets the requirements I need.

What a waste of money. left on charge overnight, i thought my house was gonna burn down with the heat generated from this crappy charger.
Lights come on but never turn off so its impossible to know when they are at full charge ( if they ever reach full charge).
Battery life is woefully low, i used it for my Radio Controlled racing car and got about 3 mins of constant use then, zip ! batterys flat dead. charged them again overnight. woke up, same deal. batterys scorching hot to the touch and 3 or so minutes use in my RC car before dying out completley.
This charger now rests comfortably in the bottom of my garbage bin, awaiting for the bin man to come and take it where it belongs, in a land fill.
kept the actual batterys that came with it and now charge them in my brand new Duracell charger, works like a charm.
very surprised and disapointed with Energizer ??? WTF

Duracell Value Charger With 4AA Pre Charged Rechargeable Nimh Batteries, CEF14DX4N

There are smart chargers, there are dumb chargers, and then there is this Energizer Overnight Charger.

A 'smart' charger monitors each battery's status individually, and stops charging when each battery is full. This is the only way to ensure that your batteries are fully charged but not over-charged.

A 'dumb' charger typically charges batteries in pairs only, and relies on a safety timer to terminate charging after 8-12 hours.

This Energizer CHVCWB2 Overnight charger (also called 'Basic Charger') is dumber than dumb. It has no charge termination mechanism at all. It simply charges each pair of batteries at a low current (190mA for AA, 90mA for AAA) FOREVER. It is up to you to remember to remove the batteries after certain number of hours, as estimated by:
[ Charge Time (hour) = Capacity (mAh) / Current (mA) ]

For example, if the battery capacity is 2000mAh _and_ they are completely discharged, then it takes roughly 11 hours to fully recharge them (2000/190 = ~11 hours). But if the capacity is lower _or_ they are only partially discharged, then the required charge time is shorter.

NiMH batteries can typically be over-charged at 0.1C current (which means 200mA for a 2000mAh cell) without immediate damage. So if you forgot and left your batteries in this charger for an extra day, they are not going to leak or explode. But in the long run, over-charger will lead to reduced capacity and shorter lifespan.

Instead of this primitive Energizer Basic Charger, you should consider a better product such as the Sony Cycle Energy BCG34HLD4KN Power Charger. The Sony charger is smarter, faster, and takes better care of your batteries. It will save you time and money in the long run.