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Old 01-26-2013, 05:58 PM   #1
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Post How to properly charge and discharge a battery

Can someone tell me the proper way to charge and discharge a battery? my battery is a SMC Lightning Volts 4000mAH 3.7v 14.8 Wh battery. I have a Thunder Power TP1430C charger on it. The battery seems to rest at 4.20 volts fully charged and others seem to rest at 4.22 or higher and sometimes after alot of runs my car seems to just be slow even after full charges. I was told i need to discharge the battery sometimes and im not really sure how to properly do it as i was told there is a cycle to it. Any help will be appriciated i am new to the rc sport and currently run in the carpet oval 17.5 jr truck class with a Team Associated 10R5. Thanks in advance!
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Old 01-26-2013, 08:45 PM   #2
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Can someone tell me the proper way to charge and discharge a battery? my battery is a SMC Lightning Volts 4000mAH 3.7v 14.8 Wh battery. I have a Thunder Power TP1430C charger on it. The battery seems to rest at 4.20 volts fully charged and others seem to rest at 4.22 or higher and sometimes after alot of runs my car seems to just be slow even after full charges. I was told i need to discharge the battery sometimes and im not really sure how to properly do it as i was told there is a cycle to it. Any help will be appriciated i am new to the rc sport and currently run in the carpet oval 17.5 jr truck class with a Team Associated 10R5. Thanks in advance!
Assuming its a Li-po they don't really need to be cycled, my brand new li-po only goes to 4.21V per cell when fully charged.

More so cycling is just a waste of pack life. How many cycles have you roughly had on it and have you ever drained it or damaged it?

Other wise you shouldn't exceed the 1C rating of the battery for charging for example your battery should be charged at more than 4 amps

Last edited by Night; 01-26-2013 at 10:13 PM.
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Old 01-27-2013, 07:41 AM   #3
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No it has never been damaged or over discharged,i only asked about discharging because i was told if i dont discharge the battery as some do every heat, that it wont take a full charge
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Old 01-27-2013, 07:50 AM   #4
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I leave mine at 3.85 per cell, till I'm ready to charge/ use them...
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Old 01-27-2013, 07:56 AM   #5
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A lot of the top drivers discharge there 1s lipo down to 3 volts the day of the race and charge as normal after that.Storgae again after completing a full run Just leave till next race day.
Its important not to discharge below 3volts or it is goodbye lipo.
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Old 01-27-2013, 08:00 AM   #6
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I also run a 1s lipo i have discharged it and have a cutoff at 3.5v for safety, would 3 volts be better to discharge to? and you say they do that the day of the race. So would i discharge it to 3v before i do any racing then charge it fully as normal the rest of the day?
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Old 01-27-2013, 11:44 AM   #7
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yes
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Old 01-27-2013, 12:30 PM   #8
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I also run a 1s lipo i have discharged it and have a cutoff at 3.5v for safety, would 3 volts be better to discharge to? and you say they do that the day of the race. So would i discharge it to 3v before i do any racing then charge it fully as normal the rest of the day?
3.5 for cutoff is fine. Don't go below 3.0 volts or the pack could turn to junk. Fast guys will discharge after every run and then fully charge. The batteries get a little more umpf when they're warm. A little heat is fine. Don't be afraid to charge at higher amps either. Lot of us one cell guys in oval are doing 15-20 amps. Been doing mine this way since October with new packs and no drop off in voltage so...experiment a little but don't go nuts. Watch for any puffing also. Some cheaper quality packs don't like being mis-treated!
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Old 01-27-2013, 12:44 PM   #9
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well thanks for the replies, i charge mine at 30 amps, of course it automatically drops off as it charges but now i have an understanding of why they do it, any clue to why they put a heat gun on their cars after their runs? or it looked like a heat gun to me
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Old 01-27-2013, 12:47 PM   #10
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well thanks for the replies, i charge mine at 30 amps, of course it automatically drops off as it charges but now i have an understanding of why they do it, any clue to why they put a heat gun on their cars after their runs? or it looked like a heat gun to me
Must be a Temp. gun...checking for motor heat. (No reason to heat them after a run.)
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Old 01-29-2013, 07:54 PM   #11
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A lot of the top drivers discharge there 1s lipo down to 3 volts the day of the race and charge as normal after that.Storgae again after completing a full run Just leave till next race day.
Its important not to discharge below 3volts or it is goodbye lipo.
+1

Also, not all batteries are as good as you think!

Check them from time to time.
Here's how :

+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.
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Old 01-30-2013, 08:40 AM   #12
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I suspect they are discharging at the beginning of the day to "wake up the pack". When my packs sit for a week or two they are a bit slower (maybe 5-10%). For me I usually run them as is for practice then charge at 2C in your case 8amps then run them again. Usually by the 3rd charge they are at full power. In this kind of a class where everything is "stock" you are looking at a battery war & usually skills being = the one with the best pack wins.

Personally I do think they need to be cycled every once in a while and will run my packs down to 5% (3.7x per cell) or so every couple of months. I also charge all my packs at 2C (been doing this for 2 yrs) with no problems.
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Old 01-30-2013, 11:02 AM   #13
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when you store them -> 60 to 70% of charge

cut off -> 3.2v per cell or more

charge -> 95% of the lipo for me so that the balancing goes faster

rate -> 1C and up to 3C/4C when I'm busy

in three years I puffed one single lipo (bad brand)

if you can put them in the fridge when not in use

and most importatly use a good charger and balancer, a lipo can cost as much as you want if the charger isn't good it won't be good
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