Barber420

My Feedback: (1)

I'm trying to bring my buddies 6 cell NiMh battery back to good condition for him. I discharged it on my old timed charger and plan on charging on this charger with a .1 amp trickle charge. It's a 4200mah pack, so if I'm charging at .1amps how many hours should it take? I'm thinking it's going to take about sixty hours at that level. The timed charger has no amperage setting so it's all(4amps) or nothing(.1amps). I would charge it at .4 amps, but I want it to get a real good form charge and my MRC 977 is peak detecting and I don't think I can turn that off. Will this work properly?

rcairflr

My Feedback: (44)

Here's my $.02 worth. In order to properly Form or Reform a battery, you need a non-Peak detecting charger. Check the below link to see what I use.
You would have a very hard time getting it Formed using your charger at 100mA, it would take upwards of 3 days to Form charge that 4200mA battery. Your odds of not Peak detecting would not be good. I would Form that battery at a rate of at least 300-400mA rate with a non-Peak detecting charger.

http://www.chiefaircraft.com/rcmsec/...rs/Sirius.html

guver

My Feedback: (325)

My best guess is 126 hrs, but 200-300 hrs won't hurt it.

Barber420

My Feedback: (1)

200-300 hours, WOW!!! Alright, good to know. I'll just keep checking the voltmeter every 12 hours or so. It should still do a good job of form charging it like this right? It's just going to take forever. I would look into another non-peak detecting charger that I can charge at like .5amps with, but I'm spending all of my RC money on two RC10 goldpan restorations. One is for driving the other is for the shelf. Therefore, I'm not really looking to get yet another charger just to form charge with, because I don't want to spend the money right now. Thanks for the help guys, and if you think of anything else I should know please tell me.

guver

My Feedback: (325)

It should still do a good job of forming (from 100 - 500 ma) Maybe you have an old wall wart, power suply, power pack lying around from an old device? that has specs around 200-500 ma and 5-12 volts.

Barber420

My Feedback: (1)

I don't think I have any old wall warts or anything laying aroung that I can use. If my old timed charger will work then I'll just be patient and use that. It's an OLD Astroflight Model #114 with charge and discharge capabilities. The batt has been on it for ~18hrs and is taking a charge so hopefully it'll work. I'll just let it sit for a million hours!! No, I'll take it off after 200-250 hours!! Another quick question, when I discharge a battery I should go by the voltage reading I get when I plug my voltmeter into the battery(plug) right? Not the reading it gives with the voltmeter plugged into the charger. Thanks.

guver

My Feedback: (325)

Oh, this is the charger that does 100 ma then. Yes.

The voltage should be almost the same with the battery being slightly higher reading. The more current being pulled causes the readings to seperate more.

It can probably pull the reading at the battery down to about 6 volts.

Here's what a forming charge for 15 hrs may look like with a c/10 rate. Your rate is much slower at a c/40 or so. Many people say the battery doesn't peak, but I have obversed many peaks at a c/10 . I also beleive at c/40 it will stil peak and drop at around 100-200 hrs. I've never used that slow rate.

Barber420

My Feedback: (1)

Hopefully it works, if not, it's no big deal, because I doubt it's going to work any worse than it did before. I figure this will either do nothing or make an improvement. Wish me luck. I'll let you know how it turns out doing it at this slow of a rate in about a week +.