Charger with 12 hr timer!

[tompen]

I just bought 2 Titanium CH-V6988 Chargers and 40 AA 2700 mah Titanium batteries. When I opened the charger and read the instructions it says that it charges and discharges at 250mah, and that it has a 12 hour timer to cut it off so that it doesn't overcharge. My question is can this charger fully charge 2700mah batteries in 12 hours @ 250mah? If not I need to return the chargers for something else.

Any help would be appreciated.

 

[SilentK]

Yes, they should so fine as far as getting full capactity into your cells. 12x250=3000. You still have a little free area as well

 

[VidPro]

nope it wont
that charger is 250ma but it pauses to check the voltage, so it is averaged current of 220-230 . there is some loss in charging, and so therin you will get about 2200-2300 max from full discharged battery.

its still a good little charger being slow and all, peaks out enloops beautifully. and still would work , if you use the discharge feature, then all the cells will have almost the exact capacity and no overcharge. they just wont be 100% charged. if you just use it to top off, and cells are therin at different levels, they wont work in series well. if you "reset" it and double charge the batts with a second run, for 8hours SOME of the batteries will be slow rate overcharged, which will not destroy them, but isnt nessisarily great for them either. (some of them will terminate)
it will work beautiffuly with enloops, given a discharge before charge.

but then your just going to send that back, and get a Timed 350ma 12 hour one (the one with no termination other than time), and the overcharge at 350 isnt going to be pretty either, because your in the CHEAP range of chargers that wont do well with a 2700 .

there is a 500ma and 800ma version of that thing, in at least a 8cell , because they are tight with the termination, the "fast" version of that style of charger should be better, it will charge them full up, and terminate usually properly because the rate is higher. about the same price, 2 less cells to charge a a time, and the best exchange $$$ for what you have.

it is either that or you get up into the $80 chargers (when doing more than 4 items), that work in more conditions correctally.

did i mention that they ALL have various issues so pick your poisen.

 

[tompen]

VidPro

Thanks for the information, that is what I suspected about these chargers. I will be returning them to Battery Junction for different ones.

 

[Mr Happy]

Personally, I would test the charger first before giving up on it. See if the batteries take the whole 12 hours to charge or if they finish sooner. Also measure the voltage when they come off the charger. If the voltage fresh off the charger is in the 1.40 - 1.45 V range you can assume they are fully charged.

Of course if you want a charger that is faster than 12 hours you will need something different anyway.

 

[travelinman]

First put in a discharged cell and then check what the charge rate really is! Don't rely on the manufacturer's specs. Some 250 ma chargers that I tested only put out 150 ma

It's easy if you have a volt/ohm meter. Just put 2 small strips of metal between the charger pos terminal and the cell with a piece of non conductive plastic between them. Clip the 2 pieces of metal to your v/o meter and read the amperage a few times during the charge cycle. You might be surprised.