EGO battery salvage and repurpose

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I have an EGo Battery that does not qualify for the warrantee. It is a year old but I bought it from a non authorized dealer. The charger is all green. The battery is green until it is in mower. hen the battery is orange and the mower is red. Support says it is an electronics failure. So I have a whole lot of little batteries that are good. 1. can i discard the electronics and use the battery in my EGO or reconfigure the batteries into a 12 volt configuration for my garden tracter?
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Fred Clarke

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Posted 1 year ago

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(a)Typical Engineer

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1. the electronics are the BMS, battery management system.  it controls how the batteries are charged. 

2. so if you discard the BMS, you'll need a way to charge the cells individually.

There are youtube videos of people converting Ni-Cd and Ni-MH tools over to Lithium Ion.  Recommend you check out some of those if you want to adapter individual cells to a 12v application.
 
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Blue Angel, Champion

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The orange light could suggest the battery’s temperature sensors are not reporting properly. If that was the case you could look into replacing the thermistors.
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Fred Clarke

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Two great comments. Just what I am looking for. " charge the cells individually" does that mean each cell separatly?
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(a)Typical Engineer

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yes, pretty much any charger that will charge 18650 cells should work.
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Fred Clarke

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let me give u my simplistic view and then tell me why it won't work and what i would need to do. if i connected three of the cells together in series and creat more of these sets using my 42 batteries then hook these sets together in parallel for a 12 volt battery pack. Then use a twelve volt battery charger to maintain them...its not that simple is it?
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Blue Angel, Champion

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These lithium ion battery cells top out at 4.2 V per cell, which means a series string of three cells gives you 12.6 V peak. Most 12 V lead acid battery chargers float the battery voltage at somewhere over 13 V at full charge, so that won’t work.

Automotive electrical systems often work at up to 15 V so that illuminates the possibility as well. Using a series string of four cells would get you there but the charge capacity of the cells would be around half of their potential.

I think the best approach for a custom battery pack would be to use a BMS system that can be set up for the number of cells you want to use. That way you can be assured the cells are being managed properly.
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Fred Clarke

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Thanks again for your response.The number of cells is a detail and not to the main point of stringing these 42 batteries together for some usefull purpose. we are talking about a$300+ investment getting discarded. I will try to find out what a BMS system (Battery Management System) is in reality and where one gets one for my application.