4s2p full charge

my new truerc 4s2p 8000mah pack is at 16.6 volts and still charging, isnt it supposed to stop at 16.4 volts which is 4.2 volts/cell? should i let it keep going? im using a superbrain 989 with an lba10 balancer...its put about 3000 mah into it at 8 amps...the meter says the batt is only like 1/4 full

edit: it just entered trickle at 16.8 volts, how long should i let it trickle? the amps is slowly decreasing

thanks

[bl-is-future]

you shouldnt let lipos trickle at all. And if you do your math right the cut off for a 4s is 16.8v (4.2 * 4 = 16.8) And you may not have ran it down to the cutoff. Also you say it is new so i imagine you never ran the pack yet? It will ship with some charge in it (usually a little over half). Hope this helped.

[Matthew_Armeni]

LiPos are fine to trickle, it'll put in another 50-200mah once the trickle is done.

well now i feel dumb lol, thanks for correcting my mistake...i read somewhere that with lipos the trickle will keep decreasing until its at 0.00 amps and then the lipo is fully charged...or should i just take it off as soon as it enters trickle

thanks again

well now in addition to not being able to add i cant type fast enough either lol

[Matthew_Armeni]

When it reaches 0 amps it's done, like you stated.

Lipos charge using a sequence called CC/CV - constant current/constant voltage. It will charge at CC until it reaches full voltage for the cell count (2S = 8.4v, 4S = 16.8v), then charger switches to charging at CV and the charge current will slowly fall until its zero which is where the charge is finished. This is the special charging that is needed for lipos - CC/CV and is different from charging used for Nxxx, and other types of batt chemistry.

If your lipo is new, it will need a few cycles before it will show you what its really going to be like capacity wise. Keep temps reasonable during these early cycles to get longest life and best performance.

[lincpimp]

Yep, do what Duster says. Take it easy on the lipo for the first few cycles. This will help cheaper lipos more, as the cells may not be matched as well as the high end lipos. You may also find that you have a "strong" cell, that will hold its charge better. That is why it is important to set the lvc higher than 3v per cell. I like to go with 3.2v per cell, that helps if a weaker cell discharges faster than the others. Because the lvc reads the entire pack voltage, not individual cells, you can have a problem with a 3v per cell setting.

Example, if you dischare a 3s lipo (11.1v nominal) to the lvc setting of 3v per cell, 9v, all of the cells should be 3v. Now, if you have a strongf cell that has maintained voltage of 3.2v, the other cells will be 2.9v which is not good for lipo cells.

[bl-is-future]

now everything i have read says do not trickle lipos. Why would they says this if you can trickle them? Just really want to set myself straight here. I trust you guys more than anyone else.

[lincpimp]

As long as you use a LIPO specific charger, with a CC/CV charge cycle, you can charge the lipo till the amp input is zero.

What you have read is that one should never use a nimh or nicd charger to charge lipos...

[bl-is-future]

ic thanks