LIPO BATTERIES CHARGING AND DISCHARGING

[rockthemonkees]

Sure this has been asked before but need some help.

finally joined 21st century have a lipo charger balancer as well as BL motors esc etc and now need to work the following out.

charge rates: i own the following batteries which have arrived over last couple of weeks

the charger is an imax B6 that charges disvcharges and balances .on ebay if u wanna have a look

the manual that arrived is good but does not explain clearly certain points.

Venom 20C 2S 4000mah 7.4v LiPO HardCase

Venom LiPo 3S 11.1V 800mAh 10C

overlander 2s 7.4v 60c

what should i set charger at? ie how many amps, ie the 800mah is 3s so is it still 0.8a charge rate?

how long can i leave them charged before i use them?

if i dont use them for a few days do they lose the charge?

should they be fully discharged after every use or can u top them up if only 1/2 used?

how often do they need balancing?

am i right in saying they arrive fullly charged?

thanks in advance

[tonysmini]

Venom 20C 2S 4000mah 7.4v LiPO HardCase

Venom LiPo 3S 11.1V 800mAh 10C

overlander 2s 7.4v 60c

what should i set charger at? ie how many amps, ie the 800mah is 3s so is it still 0.8a charge rate? The specs for the Venom 3s say up to 1.2amps, but I'd use 0.8. It should say on the battery or on the packaging what the highest rating is that you can use, I usually balance charge mine on 1-1.5 amps for my car packs and 0.3-0.8 for my small crawler/scaler packs, I have a few so am never short of a charged one. Just remember to change the cell count when swapping the 2s for the 3s.

how long can i leave them charged before i use them? If you are not going to use them for a few weeks, then set them on a storage charge, the charger should have a setting in the Lipo menu for this and they can last for months, if not years in this state.

if i dont use them for a few days do they lose the charge? No, I have left them for 2-3 weeks and lost nothing.

should they be fully discharged after every use or can u top them up if only 1/2 used? NEVER fully discharge a Lipo, if one of the cells drops below 3v, it nosedives and is useless. I set my lipo cut offs for 3.1 or 3.2 volts, not that I ever seem to hit them. You can top up a Lipo from any charge state.

how often do they need balancing? Depends on the quality of the battery, but I do mine every time, if the charger can handle it, why not do it.

am i right in saying they arrive fullly charged? Most turn up in the storage state 50-70% charged, but I've had some turn up fully charged. I give them a shot on the balance setting anyway.

[Backlash]

You typically charge LiPo's at 1C, or one times the battery's capacity..

For the Venom 2S 4000mA 20C, that will be 4 Amps.

For the Venom 3S 800mA 10C, that will be 0.8 Amps as you have written..

The Overlander 2S 60C pack, you have not specified a capacity, so I cant help you there..

It it not recomended that you store LiPo's fully charged, but I have charged mine a day before wanting to run them and had no ill effects..

LiPo's do not loose charge as fast as NiMh batteries do.. After a week, they may lose a few mA, which is generally not noticeable..

LiPo's DO NOT need to be completely discharged before re-charging, and it is better for them if you dont... If you discharge a LiPo battery below 3V - 3.2V per cell, you can damage the battery beyond repair.. For this reason, I suggest using a low voltage cutoff or alarm when running them..

You do not need to balance charge, every charge, but balance charge them as often as you can.. I try to balance charge mine every charge, except for the second charge they get at racing as balance charging often takes longer, and you often dont get time at racing.. I would recommend connecting the balance lead to the charger EVERY CHARGE, as it allows the charger to better monitor the battery's voltage..

They will most likely arrive partially charged, as you shouldnt store LiPo's fully charged..

[fatboyslim]

Sure this has been asked before but need some help.

finally joined 21st century have a lipo charger balancer as well as BL motors esc etc and now need to work the following out.

charge rates: i own the following batteries which have arrived over last couple of weeks

the charger is an imax B6 that charges disvcharges and balances .on ebay if u wanna have a look

the manual that arrived is good but does not explain clearly certain points.

Venom 20C 2S 4000mah 7.4v LiPO HardCase

Venom LiPo 3S 11.1V 800mAh 10C

overlander 2s 7.4v 60c

what should i set charger at? ie how many amps, ie the 800mah is 3s so is it still 0.8a charge rate?

General rule is charge at 1C i.e 1 x capacity,so charge the 4000mah at 4 amps and the 800mah at 0.8amps,just make sure your charger is set for Lipo

and the correct cell count(i.e. 2s,3s,4s etc)

how long can i leave them charged before i use them?

If you use them fairly regular then it's not a bad thing to leave them charged

if i dont use them for a few days do they lose the charge?

They do but only a small amount nowhere near as much as a nimh or nicd would

should they be fully discharged after every use or can u top them up if only 1/2 used?

NO,NEVER fully discharge a Lipo,if you do then chances are it WILL be unusable,if you're not going to be using them for a week or two then run them till you

low voltage cut off/alarm cuts in,then charge them to to around 50%,this is the best way to store them long term

how often do they need balancing?

I balance my Lipos every charge,some people don't,but given the dangers of overcharging it gives me peace or mind,also balance charging everytime means both

cells are charged evenly and it doesn't do them any harm,so why not do it?

am i right in saying they arrive fullly charged?

None of mine ever have,always around 50%

Just remember to charge them correctly and always keep your eye on them whilst charging,IF the packs show any sign of damage or swelling then be very wary of them

If you want for extra safety charge the batteries in a charge bag or something fireproof(I know someone who uses a .50 cal ammo box)

NEVER short circuit them

So long as you're careful and don't abuse them or do anything stupid you should be ok

Coupled with a brushless system Lipos are great you'll wonder why you never changed before!!

thanks in advance

[rockthemonkees]

Tony, thanks very much, clear and simple answers much appreciated.

[rockthemonkees]

thanks if u wondered have spent the last ten years restoring old vintage kyoshos, so all cars have period running gear..

but have bought new 1/5 scale bike hence the batteries.. and yes the performance of BL and lipos is astonishing from what i can see

will be testing my venom bike and anderson bike today, batteries fully charged..

Cheers guys.