Charging cell using rc charger, voltage jumps, is it normal?

So it will not overcharge it? how will the charger detect when the module is fully charged?

 

I'm not in front of my chargers right now, but I think you set the amps and the max charge at something like 8.4v or whatever the closest option is, but it will charge higher than that even at that setting. And I've never risked leaving chargers unattended. But I can tell you that battery packs that need reconditioning will fill up real fast and go above 9v. Then after three deep cycles and capacity is restored they barely will go to 8.7. Main thing is heat... Everything goes bad when it gets hot so keep things cool and recharge modules in stages, especially after the third discharge which generates the most heat when you recharge.

 

I see.

Also what do you mean with ''recharge modules in stages''?

I think that charging at 8.4v might be a little bit too high don't you think?

 

Yeah too high if you were using a battery it was designed for that's less than 20% of the weight of a single Prius module... Not for something 5 times larger...

And by stages I mean charge it up to 8v and let it cool down, then charge a different one then charge it more. A great deal of Mah sent to module is lost as heat, so don't expect an accurate measure of how much charge has been sent in Mah, but you can boost that amount by keeping things cool.

 

Well if i want to charge a module i have to put the voltage limit to 8 volts correct? and charge voltage of 8.4v, but if i want to charge the module slow can i charge it at 3v or just let the charge select automatically?

 

I'm sure you mean milliamp hours, but you've written Megaamp hours. The unit ampere, being named after a French physicist and mathematician André-Marie Ampère, means that the abbreviation, A, is capitalized. This, in turn, means the correct abbreviation milliamp hour is mAh (or more correctly mA⋅h). Just thought you'd like to know.

 

Thanks... Things wouldn't go well if you tried to put a mega amp hour into a module. Wouldn't be safe!

 

Default capacity is 6.5Ah, typical charge put in battery is 20% higher so limit for new battery should be 7.8Ah. But if you charge with low current like 350mA, it is safe to overcharge the battery. This is how prius itself is balancing HV battery if it see abnormal voltages.
Charger you use, for nicd and nimh batteries is using minus delta V charging method, it periodically stop charging, measure battery voltage and if it is lower by certain amount than previous measurement charging is finished.

 

I see, thank you very much.