Charging 36V pack with Powerlab8? - RC Groups
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Aug 16, 2017, 11:44 AM
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Charging 36V pack with Powerlab8?


Sorry about the idiot question. I bought a hundred 36v packs, wired 10s 2p with a BMS. I would very much like to use my Powerlab 8 to charge/discharge as they are but I see no way of doing this. Is it possible?
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Aug 16, 2017, 03:03 PM
BVH
BVH
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There's at least a couple problems. You need 42 Volts, give or take for your Lithium Ion/Polymer packs. The PowerLabs are for 8S max so a max of about 34.8 Volts, give or take. You can do only balanced charging on packs 3S and greater so no-go there, too. icharger has some reasonably priced 10S chargers.

Even if your packs are using LiFeP04 cells, the max PL8 voltage would work but you still need to use a balanced charge and with the BMS, chances are you don't have a balance harness wired in so out of luck there, too.
Aug 16, 2017, 03:40 PM
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Quote:
Originally Posted by BVH
There's at least a couple problems. You need 42 Volts, give or take for your Lithium Ion/Polymer packs. The PowerLabs are for 8S max so a max of about 34.8 Volts, give or take. You can do only balanced charging on packs 3S and greater so no-go there, too. icharger has some reasonably priced 10S chargers.

Even if your packs are using LiFeP04 cells, the max PL8 voltage would work but you still need to use a balanced charge and with the BMS, chances are you don't have a balance harness wired in so out of luck there, too.
Fyi - we are working on support for unbalanced charging for BMS-equipped packs on the Powerlabs. For safety reasons, it will require the use of the Bump Co troller and BumpTags, but it will enable all charges, up to the limits of the charger.
If you give us the chemistry and target charge voltage, we can tell you if it will work for your use case.
Aug 16, 2017, 06:34 PM
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I have LG (LGEAMF11865) li ion that I would like get 41v. I can access the balance connector under the shrinkwrap if needed.

If it cannot be done with the Powerlab, what can I find that will? Thanks for your help..

THIS is a killer deal.
Aug 16, 2017, 10:20 PM
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Quote:
Originally Posted by twaeker
I have LG (LGEAMF11865) li ion that I would like get 41v. I can access the balance connector under the shrinkwrap if needed.

If it cannot be done with the Powerlab, what can I find that will? Thanks for your help..

THIS is a killer deal.
That is a good deal, assuming they really are new cells.

If you can split them into 2x 5S strings for charging, then PL could do it later this year when it supports unbalanced BMS charging.
If you can also get to the balance connector and disable BMS, then you could obviously charge them now with PL.

The CellPro 10XP can do full 10S charging, but it will always require access to balance leads.
Aug 17, 2017, 08:55 PM
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Quote:
Originally Posted by RevoKelly
If you can also get to the balance connector and disable BMS, then you could obviously charge them now with PL.
This I'm not understanding, it only see 8S. I get 'Safety Warning 17: Cells No Add Up'. Could you explain?

Thanks.
Aug 17, 2017, 10:46 PM
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Quote:
Originally Posted by twaeker
This I'm not understanding, it only see 8S. I get 'Safety Warning 17: Cells No Add Up'. Could you explain?

Thanks.
Not understanding your question, please elaborate.
Aug 17, 2017, 11:38 PM
Registered User
You said "If you can also get to the balance connector and disable BMS, then you could obviously charge them now with PL."
I can access the balance connector and bypass the bms but I don't quite know enough about how to charge a 10 pack and get an error. A special plug?
Aug 18, 2017, 08:06 AM
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Quote:
Originally Posted by twaeker
You said "If you can also get to the balance connector and disable BMS, then you could obviously charge them now with PL."
I can access the balance connector and bypass the bms but I don't quite know enough about how to charge a 10 pack and get an error. A special plug?
That comment was in addition to the previous, which was that the 10s pack would have to be split into a pair of 5s packs. The 5s packs could then be charged separately or parallel charged together.
Splitting the pack means disconnecting the series connection between cells 5 and 6 and running external leads from those 2 connections - this gives you separate main power connectors.
For the balance connector, its pretty much the same idea - with the connection broken between cells 5 and 6, you will now have separate balance leads coming from each cell and cells 1-5 will be completely separate from cells 6-10 ..... electrically 2 separate 5s packs. Of course you will need to solder/crimp the appropriate 5s balance connector on each pack for charging. You can Google plenty of resources on balance connectors and wiring for the details.
There are other chargers that will handle 10s charge, but Im not sure about unbalanced BMS support. Since you have access to the balance lead, the CellPro 10XP with the 10s XH balance adapter cable would do the trick. If you require multiple packs, then it may be worth it to find a 10s charger rather than spend the time modifying packs.


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