Batteries hooked up in series

[sprintkat]

Hey guys
when i use 2 x 3s1p 5000 mah 30c discharge lipo batteries in series, arnt you supposed to hook the positive on the left side battery to the positive on the esc and then hook up the negative on the right side battery to the negative on the esc, then use a jumper to kook up the negative from the left side battery to the positive on the right side battery ??? is the correct way to hook up lipo's in series.

[dana]

yes you connect one pack to the other

[sprintkat]

Then why is it that it always drains the left side battery and sweels it up and doesnt touch the right side battery at all. after 3 minuets of run time, the soft cut kicks in and i immediatly bring the boat in. this has happened 3 out of 3 times. theres gotta be something wrong. cant keep buying lipo batteries. i know its not the esc, cause this is the 3rd esc also. all parameters are configured manually with the transmitter for the esc setup.

[dana]

i dunno… tell more about your setup. what boat, esc, motor, batteries> what have you tried so far?

[sprintkat]

29" inch sprint cat hull, got a leopard 40-82 motor, using a 100 amp continuous 150 amp burst esc rated at 35 volts with colling plates top and bottom. using 2 x 3s1p 4000 mah lipo batteries with a 20c continuous and 30c burst rate in series, no time limit on burst rate. use an octura 3 blade 440. i know this is a good setup, actually could use a 200 amp esc.
why does it always burn up the left battery ??????????. 3 different setups, 2 with hobbywing 180/360 esc , and 1 with 100/150 amp esc. all doing the same thing. ill pull the right side battery out and check the capacity, doesnt use any mah at all, but drains the left battery to zero volts, burns it up and swells, destroying the battery.

[dana]

Ihavenoidea. That has to be frustrating....

[BHChieftain]

Hi,
I'm just reaching in the dark here, but you said something about a "jumper" connecting 1 pack positive lead to the other pack negative lead. What are you using as the "jumper"? I'm thinking maybe that connection might have higher resistance than the rest of your connections.

Usually people run the packs with bullets so all of the connections have the same type of connector.

Chief

[FRED]

Jumper is used in Europe for safety by their rules. Here states, no required. Now for safety aspect, get a push-pull Du Bro switch. Take out jumper complelely and check wiring for soldering error and all round connectores are the same size and wiring is also same size.

[Chrisg81983]

Something has to be wired wrong because if any part of a series connection is bad you will get no power at all to anything

[Chrisg81983]

I am pretty suere Something has to be wired wrong because if any part of a series connection is bad you will get no power at all to anything Do you have pics of your setup with jumper installed

[Fluid]

29" inch sprint cat hull, got a leopard 40-82 motor, using a 100 amp continuous 150 amp burst esc rated at 35 volts with colling plates top and bottom. using 2 x 3s1p 4000 mah lipo batteries with a 20c continuous and 30c burst rate in series, no time limit on burst rate. use an octura 3 blade 440. i know this is a good setup, actually could use a 200 amp esc.It does not look like a good setup to me at all. Depending on the motor Kv, if you "could use a 200 amp esc" then you have totally inadequate batteries. 4000mAh at 20C is only good for 80 amps; if you are pulling over 100 amps then that is why your packs are going south so fast. 20C packs are only good for low performance use unless you parallel them - assuming they are decent quality. Better yet, get better batteries or get a lower Kv motor and run a lower amp setup.



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[Make-a-Wake]

Yep..............Jay nailed it........................160 amps continuous to feed a 4082 is way too little. I run my 4082 with 8000mah and 360a continuous.

[Chrisg81983]

Yea this is all true but besides that both batteries should still drain equally or somewhat equally he is having the problem with only one draining and the other is still at full charge

[Fluid]

Cheap packs may not drain equally. If they are hooked up properly in series, the only reason they'd discharge differently would be due to differences in the cells - poor matching, poor charging, etc. He hasn't told us the temperature or voltage in the other pack, it could be only slightly different. He may not be charging both packs fully - there are many logical explanations for what he is experiencing. Like most newbies, he doesn't know what information to give us to help him.....



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