How to charge large battery in parallel

General Discussion
#1

Hello!

I am working on an underwater RC vehicle. I want to have a large battery capacity so the vehicle runs for a long time. Unfortunately, I don’t have the space available for a large 5000mAh battery so I am resorting to using x4 individual 14.8 volt, 4s, 1400mAh batteries.

I know how to connect the batteries in parallel and use them, however I don’t know how to charge this large battery altogether. What I am trying to say is that I want to keep this large battery (made of 4 smaller batteries) together and be able to connect but also charge it in this configuration for ease of use. Other than the XT60 with power and ground, I know these batteries have cell equalizer connectors.

I would appreciate any guidance on how to charge this large 16s battery or ideas.

Thanks!

#2

It seems like you are confusing series and parallel coupling. We denote the batteries as 4s because there are 4 cells in series. If you are connecting 4 4s packs in parallel, we call it 4s4p.

When two LiPo cells are connected in parallel, they will balance each other out until they are equal. If you connect the balancing leads in parallel (making sure each cell pair has the same voltage first), you should be able to use a 4s bms for balancing all the batteries. The optimal way would be to use one bms for each battery when charging, and leaving them outside the vehicle saves space and weight.

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