Success with a Battery Doctor

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MyRants
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Success with a Battery Doctor

I recently purchased 4 Samsung batteries which were delivered in the guise of Panasonic(Sanyo) NCR18650GA high drain cellsin an EVVA wrapper.  I've been assured the batteries I received are as good as or better than the ones I ordered.  Okay, I'm new at this I can roll with it.   

As part of my ongoing education and current obsession with all things related to LED flashlights and the batteries which power them I ran them through the mAh detecter mode of my relatively new Hohm Tech Base 4 Bay Digital Battery Charger.  As I understand it, the charger charges the batteries (cells?) until the voltage stabilizes and then discharges them measuring the output in the process.  Then it charges them back to full capacity.   

These named/rated 3500 mAh cells completed the process indicating the following capacities:   

1 @ 3322 mAH

1 @ 3328 mAh

1 @ 3039 mAh

1 @ 2381 mAh 

I'm pretty sure the first two are considered within acceptable levels by battery people.  The last two not so much.

This charger has something called a Battery Doctor Mode.  It apparently oscillates and pulses with constant and stepping current to "revive, repair and nuture" weak or tired cells.

Well, after 10 hours or so, the cell previously measured at 3039 mAh finished up with 3322 mAh.  After 13 hours the cell previously measured at 2381 mAh had increased capacity to 3328 mAh.

I don't know a lot about chargers but I believe Martha Stewart would call this one a "good thing".

I'm pleased.

I purchased the charger at the 18650batterystore

The owners manual (little sheet of paper actually) is here .

 

 

 

 

"This too shall pass." -- Ancient Persian saying

Lightbringer
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Yeah, one thing battery-sellers seem to like telling people who complain that the cells they just got don’t meet spec is to “give them a few cycles, then test them again”.

Dunno if that applies to Li cells, but hey…

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carpmon43
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remember the voltage when you start charging, as most batteries are at around 3v when fully discharged, not the proverbial 2.5v. It’ll depend on who’s battery for that one.

but, if 1 cell is at 3.4v and another at 3v, they’ll both have a different total Mah input at the end.(hense the charge them a couple three times thing).

Lightbringer
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What I’ve noticed when doing tests is that once the cell hits about 3.0V, the voltage starts dropping like a rock very quickly, so there’d likely be minimal juice between 3.0V and 2.8V, even less between 2.8V and 2.6V.

Just lookit some of the discharge curves, say, from HKJ and such.

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carpmon43
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Lightbringer wrote:
What I’ve noticed when doing tests is that once the cell hits about 3.0V, the voltage starts dropping like a rock very quickly, so there’d likely be minimal juice between 3.0V and 2.8V, even less between 2.8V and 2.6V.

Just lookit some of the discharge curves, say, from HKJ and such.

that’ll be the ‘of no real use’ part of the battery, and the bit that does the most damage trying to squeeze what’s not there out for those extra few seconds of life. and of course under load the voltage sag gets awful close to the less than 2.5v kiss of death limit.