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Valence U27-12xp BMS reconfiguration

Banche1235

New Member
Joined
Jan 17, 2020
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5
Hello!

So for the last year I've been running 2 U27 - 12xp batteries in a 24v configuration utilizing the onboard "BMS" in tandem with a laptop running the diagnostic software to monitor and balance. This system works just fine in most aspects but I'm at the point where I'm interested foregoing use of this system and installing a different BMS that simplifies balancing and monitoring. Even though I haven't had any issues to date, the added features of bluetooth monitoring as well as low voltage disconnect feel like assurances that are worth having.

I purchased an 8s 100A BMS from Overkill solar and at this point am feeling a little unsure about how to proceed with the installation. I feel clear about how to connect the cells to the BMS but am unsure of how to configure the blue wires running from the BMS to the cells without removing the cells from the housing they're currently contained in.

Is there a way I can configure this BMS without removing the cells from their packaging in order to connect them in the way that the installation diagram indicates?

Below are some pictures of my current setup & the installation pdf provided by Overkill
 

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I took one of these apart last night and it's extremely cumbersome. I used an oscillating tool carefully around the case after removing the top sticker and bms board. You can see the 5 bms wires in the photos. After you remove the pack you could cut and solder the new leads to the 4p's. Hope this helps!
 

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Appreciate your write up!

Question - are the 5 balance wires (for 4s battery) available somewhere in the top compartment containing the proprietary BMS? Or does it require cutting into the lower battery compartment to gain access?
 
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