# Adding another lipo pack in parallel?

Hi. I have a 10s setup. I am running 2 5s Turnigy lipo packs in series, making it 10s. I am only getting about 10 miles or so, per charge. I was wondering if I can add one more pack, of the same type, in parallel. I’m pretty sure of how to do it, if I added 2 more packs of the same type, in parallel. It would keep things even. However, I’m not sure of how to add just one pack. Any help, ideas, suggestions, are greatly appreciated. Here are some pics. Thanks.

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You’ll have to add two or else the draw will be disproportionate across series groups, leading to unbalanced cells.

Always make sure to charge all packs to the same voltage before connecting them.

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Yeah you need two otherwise you risk uneven discharge and uneven cell wear.

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You have to have everything that is wired in parallel have approximately the same voltage, so if you try to put two in series and then another lone one in parallel your voltages won’t match and you will just be limiting the maximum voltage output to then lone battery.

Additionally, hooking up your batteries like that will result in the higher voltage discharging into the lower voltage, which is very bad for the batteries or even dangerous. As a general rule never put anything in parallel that has constituent components that are not exactly the same battery units.

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I have the same packs, started with a 10s1p (2x 5S in series) and added 2 more after ~20 charge cycles to make it a 10s2p.

From what I gathered in the battery builders thread it’s better to not mix & match packs or cells that have differing amounts of usage time, but time will tell how good the pack holds up.
Only have 4 charges on the pack but so far so good.

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You can only parallel more cells with the same S count. 10s cannot parallel with 5s no matter what you do. If you find a smaller 10s pack, you can add it to your current 5s+5s without problems.

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This mostly applies to adding cells in series. 5s with 100 cycles + new 5s to make 10s will not play well. but 10s with 100 cycles in parallel with new 10s is generally no problem.

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Glad to hear since that’s the way they’re added. The newer packs will most likely trickle charge the older ones and see a bit more usage through the self balancing but I guess they will even out eventually.

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I thought that might be the case. Thanks.

Yep. We’ll see.

So I wound up adding 2 more packs to the 2 i already have. Now I am running 10s 2p (4) Turnigys…same as you. So far, so good. I do not have a bms however. I don’t mind using a balance board and balance charger. But I am thinking of selling this build. And I think I should add a bms, to make it simpler for whomever buys it. I’m thinking of making an external bms. Just wondering if you use a bms on your setup? And what charger do you use? Thanks

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There are some guides on how to wire balance leads to two or more lipos. Make sure who you sell it to is familiar with lipo batteries, and not just the average prebuilt customer.

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have you got a diagram how you addd the other 2 lipos?

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Sorry for the late response. It was a while ago, and I don’t have any pictures, that I can find. But I think I just made a wire harness, based on the original set-up. I just added parallel wiring into the new packs… positive to positive… negative to negative. Just more time, wire, and solder. As long as you keep the blacks, and the reds together, it should be fine.

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Oh…I also wired it with xt90’s at the joining packs. So I could add more pack in parallel, as I liked. It worked out nicely. Hope this helps

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