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Finding out how many MaH are in my batteries

Vysium

Member For 4 Years
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I opened one of my old laptop's batteries up (They're Sanyo) to take the 18650 batteries out of it and I have no idea how many MaH are in them. is there any way to test them or check them to see?
 

Vysium

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Alright, that's good to know before I actually tried using them. Thanks.
 

Jon@LiionWholesale

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To answer the question, without testing equipment devoted to this purpose it's pretty tough but it's possible. Theoretically if you put a known load on it, for example a resistor, and measure it with a voltmeter as it discharges while recording times and voltages, then pull the resistor off when it gets to 2.5-3V, you could back-calculate a close estimate of mAh from that. Or if you have a constant power regulated device and time how long it's running the device that's an easy calculation.

But Sanyo is more in the energy cell business as opposed to high power cells, so while it's possible it would work with a low power regulated mod it definitely won't be able to sub ohm as Number3124 said.
 

Jon@LiionWholesale

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My understanding is that the new Xtar VC2 and VC4 can show you mah capacity of a battery assuming it is completely drained before charging.

Just looked into it, you're right it does do that. That's kind of a cool feature, don't know why no one's put that in a charger before. Of course you shouldn't be draining your batteries down that low, it will lessen the life of the battery, but still you should be able to estimate it based on a normal partial charge. It will also give an indicator of how much usable mAh you're getting which is probably what's actually useful in the real world anyway. Then once you get a sense for what that is you can compare different batteries.
 

Slurp812

Bronze Contributor
Member For 4 Years
I got a VC2, and I liek to note the MAH it takes to charge them. Typically when my G/F runs them down till her tub mod wont fire, its like 3.2-3.3 volts or so. The LG HE2s take around 1800 mah at that level. Keep in mind they do have some mileage on them. She had a vamo fry, and left the battery in it. When I got to it it was around 3.1 volts, more than usual I was going to note the capacity, but accidentally took it out midway through the charge, and just popped it back in, and forgot to note the numbers.
 

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