how to know batteries are fulled when Parallel Charging

[REX]

Hi Guys

I am very new and before making any mistakes, I decided to ask.

I am trying to parallel charge some 3s batteries.

I followed the recommendations mentioned in this forum, however, I have a very basic question.

When should I stop charging the batteries?


From the picture, you can see the voltage is 11.80 and 656mah, this is for two 3s batteries.

Batteries features:

3S
450MAH
70C
11.1 volts.


Thanks

 

[HighTechPauper]

For 2 x 450 MaH batteries you should charge at .9 (point 9) amps, and you should let it charge until it is complete and stops on it's own, they should read 4.2 per cell roughly and be at 12.6 roughly for a 3s battery. If a battery is completely drained (meaning below 3.7v or so) it can take over an hour to charge, that is one of the reasons I storage charge to 3.9v, it lets me balance at that voltage so the cells get re-balanced pretty well, and then when I go to charge to fly it takes usually less than 30 minutes or so to finish charging.

 

[REX]

Thanks a lot for your reply.

After 90 min, the batteries cells showed 4.2 as you said, and 12.6V.

However, I needed to leave thus, I could not know if the charger stops automatically.

Any advice to know if the charger stops automatically?

During and after flying, any advice on how to keep batteries for a faster charging time?


Thanks

 

[tevek]

Thanks a lot for your reply.

After 90 min, the batteries cells showed 4.2 as you said, and 12.6V.

However, I needed to leave thus, I could not know if the charger stops automatically.

Any advice to know if the charger stops automatically?

During and after flying, any advice on how to keep batteries for a faster charging time?


Thanks

You should never leave your batteries charging unattended as bad things may happen if there is either an internal fault with a battery or your charger becomes faulty. Most reasonable chargers will emit a beeping sound when the charging is complete.
I discharge to about 3.5v per cell and as @HighTechPauper has posted, you can bring the batteries up to a storage capacity so the next time you charge, the battery takes less time to bring it up to full charge and you’ll get better service out of them.
One final thing to consider, I have a spot in the back of the house that is always cool for charging batteries and close enough to keep an eye on them. Winter is not a problem, but moving into the warmer months over here can create problems for charging batteries, especially when we regularly see 35-40C days.

 

[HighTechPauper]

These LiPo batteries are very high energy devices, NEVER leave them charging unattended or your house can burn down, and have a plan on what to do if one does catch fire since you can't just pick it up and carry it outside to throw in the driveway with your hands. If you are charging at 1C and the batteries are good they will actually feel cold while they are charging, as for the charger, it should give a beep when a charge cycle is complete and the balancing function is done, there could be a setting in the charger to turn beeping off but by default it should be turned on. When you are done flying a battery and it has cooled completely you should storage charge the battery which as @tevek said will prolong the life and they will charge faster the next time you fully charge them to fly. Unless the charger is broken it will indeed stop once the charge is completed.

 

[Earthman]

Make sure you are using an automatic balance charger set to LiPo. Follow the instructions for the charger and use the Balance Charge setting rather than the Charge setting. Make sure you plug the balance connector(s) of the battery(ies) in to the charger.

Charge at a charge rate (amperage) of “1C,” which is what other folks are telling you to do.

When using a parallel board, the charger just sees a bigger ( higher capacity in Amp-Hrs) battery, which is why the charge rate is 1C x the number of batteries plugged into the board.

Only charge batteries with the same number of cells in the parallel board or you will damage the board or batteries, or may start a fire. I know from experience (stupid mistake).

I think of my batteries as “pet batteries” because they demand so much attention. You’ll get used to it.

Have fun!

 

[REX]

Thanks guys,

Thanks a lot for your help

 

[Erick Ford]

thnx guys, there was the same issue

 

[REX]

Hello all

I can not charge a 3s lipo battery.

The charger says "error connect"

It seems some cells are dead.

I check the battery and these are the readers:


1s: 0.00
2s 4.133 V
3s 4.190 V


How can know if a cell is dead? is perhaps only the cable?

Thanks

 

[HighTechPauper]

Hello all

I can not charge a 3s lipo battery.

The charger says "error connect"

It seems some cells are dead.

I check the battery and these are the readers:


1s: 0.00
2s 4.133 V
3s 4.190 V


How can know if a cell is dead? is perhaps only the cable?

Thanks

If you have a voltmeter check across the main power lead and that voltage reading will tell you if it is a bad balance lead or a dead cell. If it reads about 8.3-8.4 then the cell is dead, if it reads normal (something much higher than 8.4-ish) then it is the balance lead.

 

[coyote_dc5]

How does the charger know the correct voltage per cell? I do this and the charger only reports the four cells not eight. I understand if you just use a basic balance board then you need to start charging with all lipo cells at same voltage but this board is intelligent (apparently) so do you think it just manages and shuts off charging to a lipo when it's finished even if there is still a lipo on the board needing more ?