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Old Sep 06, 2012, 04:35 PM
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What am I doing wrong... first LiFe battery

Imax B6 charger, LiFePo4 tx battery, HK-010 watt meter/analyzer.

Charger has no specific setting for LiFe. Set to "auto" and it detected 3S. Charged to "full" @ 1.5A. No problem. Hooked up to HK-010 (which *does* have specific LiFe setting) to confirm full charge, its yelling at me and blinking "high voltage". Checked with a meter... charged to 11.95.

What's wrong? The charger or the analyzer?

- Steven
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Old Sep 06, 2012, 04:46 PM
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Nevermind... found a great answer:
Setting a 4-button charger to charge LiFePO4 or A123 batteries (2 min 12 sec)


Stupid how it works, but whatever.

The charger says right on it LiPo/LiFe so I figured I was safe. Hope I didn't turf my battery.
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Old Sep 06, 2012, 09:29 PM
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If you charged to full on Lipo setting you over charged it by a lot and it is definitely damaged. Somewhat surprised you didn't cause a fire. I would not trust it in my tx without a lot of testing first.

The method this charger uses for selecting lipo/life/lilo is quite common actually.
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Old Sep 06, 2012, 09:48 PM
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Common, perhaps... but no less stupid.

Of course, I should have been more sure before doing it, obviously. So I'm just as stupid.

In any case, as I read up more on it... I think you're wrong on a couple points. a) its not "definitely damaged". 11.95/3 = 3.98V per cell. LiFePO4 "have a maximum operating voltage of around 4.1 to 4.2 volts" (source). However, other sources (wikipedia) state 3.6V as the max, so really I don't know. It appears to be "fine" right now. It quickly self-discharged to 9.98V and has been there ever since. Not at all puffy, etc.

As for being suprised it didn't cause a fire... that's kinda the point of LiFe vs LiPo. From the same source: "Overcharging and overdischarging LiFePO4 cells will damage them, but generally without the explosive side effects." From another source: "Overcharging and overheating [lithium] can cause fire and explosions. The exception to this is the LiFePO4 battery."

Thanks for your input.

- Steven
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Old Sep 06, 2012, 10:58 PM
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Your battery may be perfectly fine.

Some have habitually 'overcharged' A123 Systems LiFePO4 cells on lipoly setting for 100's of cycles and never suffered any measurable cell degradation.

Whether the prismatic cells of the type that you purchased are tolerant of such abuse is unknown. Please do report back on how your pack performs. My guess is that no harm has been done.

Mark
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Old Sep 07, 2012, 02:34 PM
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United States, MN
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Quote:
Originally Posted by s_mack View Post
Common, perhaps... but no less stupid.
I'll give you that. I prefer the iCharger method where it's simply another item on the main screen you can select just like amps and cell count.
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Old Sep 08, 2012, 10:05 AM
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If your resting voltage is 9.98 then the pack is still not full. Even though you had a termination voltage setting that was too high , it didn't "hang" there long enough anyways. I only have 1 of these LiFe packs , but it sure appears to have a sharp knee at BOTH ends of the voltage graph.

Now where did I put my 10.8 sized voltage cramp?
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