How do I charge a Zippy 8s that has 2 balance leads?

I tried searching the forums for a solution but I couldn’t find any related topics.

So I kinda messed up and bought a Zippy Compact 8s 5800mah.

I received it today and instant regret occured. (Why didn’t I buy 2x4s instead??)

This battery for some reason has 2x4s balance leads and I don’t know how I’ll be able to charge it. I don’t have a BMS or even a balance charger capable of 8s. My charger is 6s maximum.

Again, I don’t know why I bought this damn battery in the first place. Late night browsing isn’t the best idea.

What are my options here? Buy a BMS or a new 8s charger and a series balancing board? I’m guessing I can’t charge them in my current balance charger as 4s using one balance lead at the time?

The balance lead is split into two 4S leads, probably because 8S is not very common. Honestly, I would return it to HobbyKing, especially since you already have a 6s max charger. You’ll lose a bit on restocking fees but overall it would be cheaper than finding an 8S charger. 8S balancers are $100+, usually about $140-ish

Your other option would be to buy an 8S BMS and get rid of the Lipo balance charger all together. I use lipos with a BMS at 12s

Which BMS do you use? Do you only use it for charging? If possible could like explain how it is hooked up? Thank you!

I think it might still be ideal if ur not agAinst taking off the shrink wrap and carefully splitting the pack into (2) 4s packs. Don’t even electrically disconnect them and leave the tabs alone. Reshrink wrap or duct tape.

Charge in parallel. Battery-medic-like balancers I like and use

I’m curious what the two balance leads look like? Is there any way to distinguish between the two (without using a voltmeter)? The order in which you connect your 2x 4S leads will matter

@Hummie: I guess I could open it up. At this point I have nothing to lose because I’ve already written this purchase off as stupidity kinda. Do you have a link to the battery-medic-balancers? Are there any guides to splitting lipos?

@jmasta: The look exactly the same on the outside. Same color leads in the same order. I’ll post some pictures after opening it.

if you search for splitting lipos you’ll find details but it’s straight forward…with a credit card and patience maybe. or maybe you’ll get lucky and there will be no glue. but since you’re just making one split and no electrical disconnect it’s very easy. peel and split and don’t zing yourself.
search for battery-medic or cell balancer or something and there’s a couple out there but you could just use your charger and do in parallel, bulk charge or set it to some other chemistry on your charger, and put the medic things on. or risk plugging your balance plugs in the wrong order. zing again.

Ok, this is where I’m at right now. If I’m splitting this into 2x4s, I guess I have to solder new wires for pos and neg, right? How do I know where to solder them?

I wouldn’t bother disconnecting any tabs or wires, just split it in the middle from the bottom. the wires will need to be insulted from each other as they fold in upon themselves. put some well chewed gum in there or something. double bubble or some other insulator. make sure it won’t wear away or else zing again. then re shrink wrap it or duct tape or something and then it’s longer and not as thick

I don’t get why you want to make 2x4S batteries out of them. Just leave them as they are and charge one 4S part after the other part via only the balance leads.

yea I’m just saying you can do that with them thinner. same wires don’t mess with them.

What? why would that even matter?

i don’t know what we’re talking about. I’m saying if he want to make it flatter he can by simply cutting the pack in half (not the wires) and that’s it. charge the same. longer and thinner same battery

Haha, what the hell… Can I hook the + and - to my charger and then one of the balance leads to the charger?

Will this charge 4 of the cells at the time? Or will it balance 4 of the cells and not the other 4?

don’t connect the main lines because there the entire voltage of 8S will be present. But with low charging currents (~2A) you can safely use the balance wires + and GND as main lines.

oo yea you can’t do 8s on your charger. so program it to a different chemistry that doesn’t require balancing. then charge using the main leads still and you’ll need battery medic like balancers to monitor . more dangerous maybe as the balancers (battery medic things) are slow to balance

Do you have a more detailed explanation? How do I set this up and how would I use + and GND from the balance leads as main lines to the charger? I really don’t want to blow anything up here…

Really appreciate your input here.

same for second balancer cable after you have charged the first 4S part. You will have to make yourself a custom balancer wire to get the main lines connected.

Edit: just realized I made 5S balancing cables - but principal is the same.

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If ur charger will allow u to charge through just the balancw leads.

A custom main lead wire as he says will let the charger have half the full Voltage through the main leads and charge at 4s. Alligator Clips to Half the pack

You have option

I’d rather charge the whole pack at once rather than twice by setting the charger to another chemistry that willl do cc/cv and plug some balancers on (battery medic)