Lipo Question

Old 08-25-2009, 07:29 PM
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I just bought an extra lipo off ebay and plugged it into my balancer and charger. It is a 4c lipo and it being reported as 16.5V even though the max should be 14.8?

Should I not use it. Is it OK to discharge and use?

Thoughts?
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Old 08-25-2009, 07:46 PM
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The max voltage for a lipo is 4.2v per cell. So you are allowed 16.8v for a 4 cell lipo. Your pack is just fine. It is actually close to fully charged. You could run it and then charge it.
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Old 08-26-2009, 06:54 AM
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Originally Posted by TimV
The max voltage for a lipo is 4.2v per cell. So you are allowed 16.8v for a 4 cell lipo. Your pack is just fine. It is actually close to fully charged. You could run it and then charge it.
+1 maybe check that it's balanced or just don't run it down to far before charging and checking that it's balanced, you do balance your lipos don't you
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Old 08-26-2009, 01:19 PM
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Lipos can be confusing cause there are 3 voltages talked about - a min voltage, a max voltage and a nominal voltage. Min voltage is somewhere around 3v/cell (don't discharge below this), max voltage is 4.2v/cell (this is what the cells are charged to by a lipo charging protocol) an the nominal voltage of 3.7v.cell. This is supposedly what the cell voltage is when the cell is being discharged.

4S can be as much as 16.8v (4.2 x 4), so your lipo is fine as pointed above.
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Old 08-26-2009, 04:57 PM
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Originally Posted by Duster_360
Lipos can be confusing cause there are 3 voltages talked about - a min voltage, a max voltage and a nominal voltage. Min voltage is somewhere around 3v/cell (don't discharge below this), max voltage is 4.2v/cell (this is what the cells are charged to by a lipo charging protocol) an the nominal voltage of 3.7v.cell. This is supposedly what the cell voltage is when the cell is being discharged.

4S can be as much as 16.8v (4.2 x 4), so your lipo is fine as pointed above.
Thanks a lot for all the help.

When I was charging another 4 cell lipo on my TP-1010C with a 210v balancer I let it get to 16.8V expecting it to shiut itself off. When it hit 16.8, I was surprised to see it kept charging. I needed to shut it down manually.
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Old 08-26-2009, 05:10 PM
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Originally Posted by Garet Jax
Thanks a lot for all the help.

When I was charging another 4 cell lipo on my TP-1010C with a 210v balancer I let it get to 16.8V expecting it to shiut itself off. When it hit 16.8, I was surprised to see it kept charging. I needed to shut it down manually.
Lipos use cc/cv, it will charge to 16.8v (about 90% full) and then the charger will hold the pack at 16.8v and then continue to charge lowering the input amps as it reaches 100% and then shut off. Freaked me out the first time too It simply wasn't done charging yet.
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Old 08-26-2009, 06:10 PM
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You let it charge thru the constant current stage (CC). Lipo charge protocol switches to constant voltage (CV) when the cells reach max voltage. You watch next time and you'll see the current decrease at constant voltage as the lipo finishes topping off. Current will get very close to or down to zero and if the balancer is satisfied with balance between cells, charger will signal charge complete and terminate. Try it next time.

Freaks nearly everybody out the 1st time if you don't know whats going on. Chargers that have a "fast" lipo charge setting - they just stop after the CC stage to save time. The CV stage takes the longest and puts in the smallest part of the lipo's capacity.
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