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Do I smell 20W IR 18650 handhelds?

Toke

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Sorry, I misunderstood the battery type and simply thought you wanted to charge 3 3,7V batteries at a time. :oops:

Here is a charger for batteries with at a cut-off of 3,6V.
At $20 it is more expensive than regular chargers, I doubt there is much to do as those cells are not that common.

ETA: The charger you have found at $13 is not likely to work unless you figure out how the output plugs are connected. It
looks like there is a common + and then a - for each battery in the packs, but you will still need a plug of that type, or some other way to connect.
 
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DTR

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Ordered that charger yesterday. Report back on how it works out.:beer:
 

DTR

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Got the charger today for these Lifepo4 batteries. I did not end up needing the PVC tube to hold them while charging. Just needed a few of the earth magnets that I got of DX.




I was wondering since these are designed to work on packs where the batteries are in series and discharged together. If I take one and use it then try to charge the two charged ones with the one dead one in series will I run into the rapid charge problem? I know this is a problem when the batteries are in parallel if they are discharged to different voltages.
 

Toke

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Yes, I am afraid so.
Trying to put the full charging current through a flat and two full batteries cannot be healthy for the full ones.

You will get a over voltage at the full ones, which may or may not make them explode. The other charger you mentioned, the one for the specific pack had a wire for each battery in the pack, to monitor/charge them individually even though they would be discharged together as a pack.

You will have to use all 3 before recharging them.

ETA:
I thought you went for the single cell charger, that would have eliminated this particular problem.
Do you know if your cells are protected or not?
It would make even discharge through a small resistor a lot simpler.
Otherwise you will have to make an arrangement like a LD test load with 4-5 diodes and a resistor to discharge them gently down to 2,5V.
 
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DTR

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Thanks Toke. That is what I thought and I will be using this in a 3X18650 setup anyway.:beer:
 

Toke

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Thanks Toke. That is what I thought and I will be using this in a 3X18650 setup anyway.:beer:
Ok, then you will likely be alright.
Just make sure they stay together and none is used elsewhere. :)
Perhaps some tape and magnets would be in order to make a pack/cylinder and reduce the risk of mistakes.
 




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