How hot should batteries be out of the charger?
- Thread starter Caesis
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VidPro
Flashlight Enthusiast
burning your hand is to hot IMO, and it hurts too 
TakeTheActive
Enlightened
Specs please... (X.XX VDC @ Y.YY mA; Series or Independent Channels)
Specs please... (mAh, manufacture date, # of cycles, etc...)
Well, room temp is 70°F, so 2x is 140°F - that's pretty darn hot. For example, the La Crosse BC-900 automatically shuts down at 127°F. Maybe they're just 'warm'?
Healthy, vibrant cells charged at 0.5-1.0C in a properly terminating 'Smart Charger' only get 'warm'.
Not unless you're charging already charged batteries at a high current and not terminating properly.
funkychateau
Enlightened
Older cells seem to heat up worse than fresh, new ones. If you have some batteries that seem to heat up a lot more than others, they may be marginal anyway.
In my LaCrosse BC9009 charger at 500 ma, my oldest batteries reach about 120 degrees Fahrenheit (surface temp) just before completion of the charge cycle.
VidPro
Flashlight Enthusiast
hmmm, older cells often higher resistance, high reistance with constant currents is higher heat output. lower resistance when charging with constant current usually means terminations of higher voltages.
me thinks a pattern doth form here.
P=I/R squared or some such thing
meaning the cell has become a big hot resister (so to speak) and more of the power going in is wasted as heat, and the smart charger with say a 2V peak max voltage just keeps cranking away on the poor thing, even if the voltage has gone all up to 1.7v. then because its all loose and high resistance, the V-drop termination doesnt get observed as easily, because the voltage is going through the ceiling, and the termination that should occur still has not. and well you get the picture.
its dead, and if it wasnt it certannly will be after that
112-120*F temps when at the final stages of a reasonably fast charge are actually common, i have measured those kinds of temps in a about 76*F room temperature on a finishing cell many times.
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funkychateau
Enlightened
Actually, 600 °F is twice as hot as 70 °F.
(why is there no wise donkey symbol?)VidPro
Flashlight Enthusiast
Actually, 600 °F is twice as hot as 70 °F.
is that in Kelvins? because with batteries were measuring in Jewels instead you know :tinfoil: or do we call them James Prescotts?
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Mr Happy
Flashlight Enthusiast
Not Kelvin but Rankine.
70°F is 530°R, and twice that is 1060°R, which is 600°F. (You add 460 to Fahrenheit temperatures to get absolute temperature on the Rankine scale.)
VidPro
Flashlight Enthusiast
Not Kelvin but Rankine.
70°F is 530°R, and twice that is 1060°R, which is 600°F. (You add 460 to Fahrenheit temperatures to get absolute temperature on the Rankine scale.)
oh ok now i understand , , , why we keep sending out sofisticated scientific messages to aliens in space, and none of the aliens ever write back. :thumbsup:
TakeTheActive
Enlightened
[Need you get your total post count up, eh?Actually, 600 °F is twice as hot as 70 °F.
]Not Kelvin but Rankine.
70°F is 530°R, and twice that is 1060°R, which is 600°F. (You add 460 to Fahrenheit temperatures to get absolute temperature on the Rankine scale.)
Yep, you caught me!
Certainly Caesis *MUST* have been referring to 'Rankine / Kelvin / WHATEVER' when he originally stated "...they are still like 2x hotter than room temp...".
Mr Happy
Flashlight Enthusiast
If the cells came off the charger at 600°F they would be ... SMOKIN'!
Turbo DV8
Flashlight Enthusiast
Not Kelvin but Rankine.
70°F is 530°R, and twice that is 1060°R, which is 600°F. (You add 460 to Fahrenheit temperatures to get absolute temperature on the Rankine scale.)
Actually it doesn't depend on the scale as long as the temperature is absolute. If you converted the temperature to Kelvins and back to degrees Fahrenheit the result would be exactly the same. So VidPro was also right
You still use degrees Fahrenheit in scientific messages to aliens? Probably imperial units too
No wonder they don't understand. AFAIR they completely switched to the metric system two or three years before the UK started the transition. Stupid, stupid NASA...
Lightcrazycanuck
Banned
Egsise
Banned
Have you ever thought why we don't speak to ants?
VidPro
Flashlight Enthusiast
I do, but then my sanity is not in question here :naughty: The ants and me are just having a minor conflict on the "My Stuff" "Your Stuff" thing, but we will work it out eventually.
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