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Old 02-13-2014, 12:33 AM   #1
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Default Battery cut off and voltage

Hi all,

how does a esc protect against a battery being overly discharged? I assume it monitors battery voltage and cuts the juice at a certain point? I know that lipos hate to be over discharged.

Also, I have lipos that have sticker saying dont charge over 4.2V per cell but my Swallow charger is pushing over that, is this a problem and should I bin the thing and get a shiny new something or other....?

thank you
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Old 02-13-2014, 04:57 AM   #2
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Quote:
Originally Posted by Fly'n Fish View Post
Hi all,

how does a esc protect against a battery being overly discharged? I assume it monitors battery voltage and cuts the juice at a certain point? I know that lipos hate to be over discharged.

Also, I have lipos that have sticker saying dont charge over 4.2V per cell but my Swallow charger is pushing over that, is this a problem and should I bin the thing and get a shiny new something or other....?

thank you
The esc monitors the battery voltage and will enter LVC (Low-Voltage Cutoff) at a preset figure which can usually be set by the user. I set mine to 3.4v per cell so in a 2s pack it would cutout at 6.8v on load.

You are correct in that one of the worst things you can do with a lipo is take it down too low. As a general rule I won't take my lipos down past 3.4v per cell at the extreme.

In competitions where you have 5 minute runs you rarely get anywhere near LVC and so many pro racers disable the LVC completely but I wouldn't recommend that for practice or bashing.

The max you should charge a lipo to is 4.20v per cell. Its actually against competition rules to charge above that nor is it safe. Ive seen lipos explode when charged above 4.20v per cell. Your charger may have a setting deep in the menus to set the charge voltage correctly - to me it sounds like its setup wrong or charging the battery in the wrong mode entirely. Check that it is set to LIPO mode.
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Old 02-13-2014, 04:58 AM   #3
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Forgot to mention that there are lots of LIPO/LVC/Charging discussions over on the Radios/Electronics forum....
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Old 02-13-2014, 09:01 AM   #4
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Best chargers are the ones that charges at 1amp, then drops in amps to when they're .02amp and shut off when Balanced cells. You can monitor cell charge per cell. Lipos say discharge should be 3.0v per cell. Better ESC you can turn up cut-off volt. to 3.2v. When charging multicell pack the charger drops to a average of volts per cell, one cell could be 3v opposite cell could read 2.98v. I'd always charge my cell equal to mah rating, cuz heat is the bad part. Never overcharge, anyway it a waste. Lipos are higher discharge rate.
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Old 02-26-2014, 09:05 PM   #5
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Most of the balance charger can help you avoid over-charge, as long as you set it in a proper way. And you can use the ESC's programing mode to set the LVC to 3.2V volts per cell with a hard cut-off; or 3.4 volts per cell with a soft cut-off. Of course, soft cut-off will be better, and do good to your battery and RC vehicle.
And you can get a balance charger from WtoToy.com , if you needed.
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