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Re: (ET) motive power sources

Many 18 to 20V  ( and the 40V Ryobi & 56V EGO and others) tool batteries use 18650 or 21700 cells.
The big name brand tool manufacturers often use Samsung, LG, and other high quality cells. The off-brand replacement packs are frequently much poorer quality.
Study Battery University website for great general info, or any cell manufacturers data sheets for the specific cells in your various packs.
Look at the discharge curves (high amp draw reduces the stated capacity of the cell).
Look at lifespan curves - deep discharge reduces the total number of cycles and life of cells.
A weak cell will usually cause the BMS in the pack to shut it down, make it non chargeable. 

Cells in the packs are spot welded together.
Replacing a damaged/dead/weak cell can be challenging, and MATCHING a NEW cell into an old pack requires individual cell analysis for the old/good and new cells, else they might not discharge and recharge together correctly. 



On 5/12/24 15:05, Mike Finck via Elec-trak wrote:

I recall reading/hearing that an Electrak can be motive by plugging in the 
charger (with an extension cord) and using it as a power source, sans 
batteries. Comments?

Also i was wanting a temporary/portable battery pack just for short 
distance moves for an  E-16 that i do not keep batteries in. Seeing the 
battery powered ZTR mowers using multiple tool batteries for power I 
schemed up a tote box using 4 Ryobi 18v tool batteries wiring them to 
produce 36v. I had found caps/sleeves/adapters that slip over the battery 
post with 12ga leads. Perfect. And the tractor worked! However, one of the 
off-brand batts failed. I disposed of it months ago but recent reflection 
i believe I used 2-3amp/hr and 2-1.5amp/hr batts. Perhaps that is relevant 
info.
As an aside, what might the range be for 4-3amp/hr batts?
Thanks for any discussion 🙂
Mike
Pix would be fun but i don’t know how to keep them from being scrubbed.


Sent from my iPhone

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