Charge depleted battery

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I have a battery that was depleted to a point where the light would not turn on when I push the button. When I put it on either the standard charger or the quick charger the light on the charger just flashes red on and off is there anyway to get this battery to charge?
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Ben

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Posted 2 years ago

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Blue Angel, Champion

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Ben, how did the battery get discharged that low?  How do you know it's discharged too low and there's not something else wrong with it?  If this happened while using it on an Ego tool it should be covered under warranty.

Other than manually charging the battery back up to a reasonable voltage with a power supply, I'm not sure if there's anything else you can do.  Manually charging the battery may bring with it some risk and a voided warranty.
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Ben

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My very own Blue Angel reply I am honored.


I picked the battery up on the local classifieds for $20. So really at that point I didn't figure there was much of a warranty anyway. The person I bought it from bought it from a local sir plus center last fall and it was sitting since then because they didn't actually have a charger for it .


I put the voltmeter on it and it came in at 31 V
(Edited)
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Blue Angel, Champion

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Yep, the warranty is only good for the original purchaser who registers it with Ego.

If you have access to a DC power supply you could try charging it up, but I'd be hesitant to try that without going inside the battery to make sure all the cells are at the same starting voltage.

I got a defective battery from a forum member here a while ago, a 4Ah unit.  Same thing, I measured the voltage and it was low.  Going inside to have a peek, half the cells were nearly dead and half were still charged fine.  Had I just tried to charge the battery back to 56V I likely would have overcharged the cells that were not depleted, possibly damaging them or worse, causing the cells to rupture (or whatever these particular cells would do, they're all different).

If you're comfortable checking things out inside, go for it.  If not, you're better off not risking injury or property damage messing with it. It was only $20.  ;-)
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Ben

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I have no issue pulling it apart to test the cells. Are they soldered together I assume?
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Blue Angel, Champion

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Yes, standard spot welded tab construction. Be careful pulling the endcaps off, they tend to stick and the fine balancing wires are easily pulled out of their connectors.

The case comes off clamshell style and you should be able to identify the voltage steps. Just be careful not to short anything out... you're at your own risk! :-)
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Ben

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Alright thanks for the tips I will see if I can work a tear down into my weekend. I have a nice multi chemistry charger I could use to try and trickle the pack or individual cells back to life. If nothing else I paid $20 for an electronic adventure.
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Blue Angel, Champion

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If you can't save the pack maybe some of the cells will be salvageable. They're high quality high-drain cells.
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Ben

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Yeah I was thinking drill battery retrofit.
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Jacob

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If you have 2 batteries, cant you just connect the 2 positives together and negatives, shouldnt that equalize them? But keep an eye on them.
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With a resistor in between that might work. I'd be concerned about too much power transfer with no resistance.

Gotta be sure you don't over-discharge the donor battery as well. My main concern would be to make sure all the cells are at the same voltage before attempting a charge.
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Albert Connie Ross

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My 5.0 did that I just put it back in my lawnmower kept trying to turn it on until I got the normal red recharge light then it took the charge

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