I've run into a LiPo problem

ESK8 Electronics
5

They were both the same age, and they were both balance chargedā€¦ kinda. I usually charge them until at 4.4Ah for about 100 minutes. The reason I say about 100 minutes is it charges for 80-90 minutes at like 4.4Ah then I let it balance as it goes between 0-.1 for another 10-20 minutes till I stop it (all the cells are within 0.01V) If I donā€™t stop it, it goes on for another 30 minutes being completely anal about the cell balance. Yes, I realize that makes me sounds ignorant.

I was under the impression that they will all equal out and drain equally because the battery will pull from the highest cell. Is this not correct?

6

Is it possible to instead hook up the balance plugs as 1 6s battery so I donā€™t have to charge separately?

So charge them at 6s, 4.4Ah.

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I donā€™t think that is correct. Thatā€™s why itā€™s so important to charge on balance mode and let the charger run its full cycle until it says itā€™s done.

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Well shitā€¦ Guess I learned a $60 mistake. I guess it could have been worse and blown up, and been a $200 mistake.

So I should probably buy two more packs?

9

Yes, you can charge them in series as a 6s. Your battery puffed because you drained it too low. I did that once with 2 brand new 6s packs. better not go below 3.6v when riding. The lower your battery gets the lower its voltage goes and the more amps you pull out of it so the faster it goes. Its like a vicious cycle. and voltage sag makes it even worse because the closer your amp drain is to the batteryā€™s capability, the lower the voltage sags under load.

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How can I monitor this when I cant set the LVC of the escā€¦ Just keep an eye on it with the little balance plug meters?

I donā€™t know what LVC is set to nor how to change it.

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get an alarm meter that plugs into the balance harness and monitors each individual cell.

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https://www.amazon.com/gp/product/B0064SHG0Y/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

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The problem with that is the batteries are in the enclosure so if/when it goes off I canā€™t really turn it off.

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you set the alarm for 3.4v and if it goes off you stop riding

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So if Iā€™m far from home I can just turn the board off and push back and it wonā€™t make a peep?

Will it go off from voltage drops while Iā€™m going up hills because the batteries are only 20C/30C

Iā€™ll probably get this basic one from HK because I gotta get my new packs from there.

http://www.hobbyking.com/hobbyking/store/_58827__HobbyKing_8482_Lipoly_Low_Voltage_Alarm_2s_6s_AR_Warehouse.html

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If going up a hill sags the voltage below 3.4 then it would go off and you would want it to go off.

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The one from hobby king looks good. as long as the alarm is loud enough

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I just checked the cells on my puffy pack:

Cell 1: 3.54V Cell 2: 1.89V Cell 3: 3.10V

Thereā€™s something terribly wrong with this pack. :astonished:

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This also means it would always be plugged into the pack under the enclosure and it would drain the packs eventually then just go off and scare the crap out of me.

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You could run your balance leads to a series adapter cable and run it outside to enclosure and mount the alarm on the bottom of your deck outside the enclosure

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Thanks for your help dude!

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your welcome

23

Could also check the IR of the individual cells if your charger is capable of that. Looks like you had a bad cell and could have possible noticed it earlier if you periodically checked the IR. Like Namasaki said if you set it to 3.4 it will beep but the lipo is almost always sagging alittle when your riding and if you stop when it beeps volatge should raise up to ā€œresting voltageā€ and the alarm will go off. Cells with high IR will drain faster (sag more) then lower IR cells and will make your charger work double time to try and balance that bad cell. Just my 2 cents

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24

i had the same puffy problem and i had to throw the battery, i think that i over discharged it too much :frowning:

I created some threads to better understand the lipo batteries:

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