This thread is privately moderated by roballoba, who may elect to delete unwanted replies.
 Jan 30, 2012, 03:00 PM Registered User Joined Mar 2006 505 Posts The 460mah rating is the battery capacity. The battery can supply 460 milliamps of current for one hour. (should not drain the battery that low though, 80% is a good point). You are correct in that a 1C charge is 460ma, a 2C charge is 920ma, etc... The battery discharge rate is not a consideration for charging. The thing to be careful with when charging is to not exceed the battery voltage by selecting the wrong number of cells on the charger. Charging a 2S battery with the charger set to 3S will cause problems if the charger allows cell overvoltage. (assume it will)
 Jan 30, 2012, 03:45 PM Registered User United States, IL, Forest Park Joined Jul 2011 116 Posts Thank you for the response. So in general, is it ok to charge a battery at 1C (which I am assuming will take 1 hour)? Also, I know each cell holds 3.7V in a lipo battery. However, when I charge it, my charger says each cell has a higher voltage than that (and I did double check that I charged my 2s battery on the 2s setting). Thanks!
 Jan 30, 2012, 05:08 PM characters welcome! United States, CA, Bear Valley Springs Joined Feb 2000 27,072 Posts A fully charged lipo cell is 4.2 volts. mw
Jan 30, 2012, 06:31 PM
Easy on the Sticks!
United States, WY, Crowheart
Joined Aug 2011
4,699 Posts
Quote:
 Originally Posted by thebuckeye Thank you for the response. So in general, is it ok to charge a battery at 1C (which I am assuming will take 1 hour)? Also, I know each cell holds 3.7V in a lipo battery. However, when I charge it, my charger says each cell has a higher voltage than that (and I did double check that I charged my 2s battery on the 2s setting). Thanks!
Yes it is perfectly fine to charge at 1C, which in the case of the 460, that would
.46 amps. Like Mark says, 4.2 volts is fully charged, 3.7 volts is the minimum that you do not want to run your battery below. 3.85 volts is about half charged and where your batt should be for storage of longer than about a week.

Keep in mind that a typical 12v car battery, is fully charged at 12.6v, 75% charged at 12.4v, 50% charged at 12.2v, and dead at 12.0v. Somtimes it helps to explain it this way. Some peeps may assume that the batt would have to be at 0 volts to be dead. Not true.

Don't let Spog's post confuse you, I am sure what he means to say is never use more than 80% of your batt, leaving 20% or more at all times.

In theory, 1C should take 1 hour, but they usually charge in a bit less time than that, because remember we are not running them down to a completely dead state.

Some battery makers are claiming a charge rate of up to 5C or 6C, but I don't like it and still charge at 1C.
Last edited by BattleDude; Jan 30, 2012 at 06:43 PM. Reason: Spelling
 Jan 30, 2012, 06:44 PM Registered User United States, IL, Forest Park Joined Jul 2011 116 Posts Ok. That is what I have been doing. How do I know when there is about 20% life left? Just play around with it until I get the timing right and it takes about 45-50 minutes to charge (at 1C)? Would the battery go bad if it dropped below 3.7V? Thanks for all of the help! I really appreciate it.
Jan 31, 2012, 09:15 AM
Easy on the Sticks!
United States, WY, Crowheart
Joined Aug 2011
4,699 Posts
Quote:
 Originally Posted by thebuckeye Ok. That is what I have been doing. How do I know when there is about 20% life left? Just play around with it until I get the timing right and it takes about 45-50 minutes to charge (at 1C)? Would the battery go bad if it dropped below 3.7V? Thanks for all of the help! I really appreciate it.
You can't be accurate that way, because you don't know how much is left in the battery you are fixing to charge. What if you have 50% left when you begin to charge? Then it is going to take much less time to charge the batt.

Battery will go bad quicker if you drop the voltage below 3.7v, again and again.

If you have a digital charger, or DVM you can use either one to calculate 80/20%. Here some info that may help you do that:

If you don't have anything to measure volts/amps/ohms with, and are using the stock Celectra charger, it would be better to time your flights, when using a fully charged batt. Limit your flight time to 4 minutes, maybe 5 minutes for a stronger batt.

Or, after breaking in your batts with 6 easy 2-3 minute flights, you could time your flight to see how long it takes to reach LVC(not a good thing to do again and again as it will shorten the life of your batt) Say it took 5 minutes to reach LVC, multiply 5 minutes by .8 (80%) to reach a figure of 4 minutes. See?

It is best to have a DVM which can be bought for 5-10 bucks. Let the battery rest 15 minutes after flights, and check the batt voltage. Keep increasing flight time untill resting voltage starts to come down to 3.7v.

Or just get yourself a good digital charger, which takes care of much of this for you:
http://www.amazon.com/Thunder-Balanc...8023428&sr=8-1

Presto! There you have it!

Cheers!
Last edited by BattleDude; Jan 31, 2012 at 09:42 AM. Reason: Spelling
 Jan 31, 2012, 02:40 PM Registered User United States, IL, Forest Park Joined Jul 2011 116 Posts Ok. Perfect! Thank you for all the help!
Jan 31, 2012, 06:29 PM
Easy on the Sticks!
United States, WY, Crowheart
Joined Aug 2011
4,699 Posts
Quote:
 Originally Posted by thebuckeye Ok. Perfect! Thank you for all the help!
Sure Bud, anytime!
 Feb 06, 2012, 09:21 PM Registered User Joined Nov 2011 6 Posts Finally, I find this post was started in 2007, it lasts five years.
Feb 08, 2012, 07:48 PM
Yo R Wee Too Lo
United States, OH, Cleveland
Joined Oct 2011
894 Posts
question

Quote:
 Originally Posted by Batter Finally, I find this post was started in 2007, it lasts five years.
I usually charge my batts when I get home from flying. then I might not use them for 4 or 5 days , they seem not to have a full load of power,

another thing I do which could be a factor I have a nine eagles charger 3.7 volt from my sp328 instead of charging one battery at a time I made a connector (spider) to charge 3 at a time , I charge them at the lowest rate , could the charger be not charging them to full power along with the downtime between sessions be a factor. may be one at a time is better??
Thanks
Tonytester
Feb 09, 2012, 09:08 AM
Things that do fly
In my house ;-) The uk
Joined Dec 2008
2,714 Posts
Quote:
 Originally Posted by tonytester I usually charge my batts when I get home from flying. then I might not use them for 4 or 5 days , they seem not to have a full load of power, another thing I do which could be a factor I have a nine eagles charger 3.7 volt from my sp328 instead of charging one battery at a time I made a connector (spider) to charge 3 at a time , I charge them at the lowest rate , could the charger be not charging them to full power along with the downtime between sessions be a factor. may be one at a time is better?? Thanks Tonytester
You need to measure the voltage of each lipo after charging ,only way to know dude.
 Feb 09, 2012, 12:04 PM like a rock! Finland Joined Oct 2007 2,473 Posts your batteries will perform better when you charge then immediately before use. One obvious reason is that charging warms them up slightly. A couple of degrees can make a huge difference.
Feb 09, 2012, 05:56 PM
Yo R Wee Too Lo
United States, OH, Cleveland
Joined Oct 2011
894 Posts
thanks

Quote:
 Originally Posted by gravityKills your batteries will perform better when you charge then immediately before use. One obvious reason is that charging warms them up slightly. A couple of degrees can make a huge difference.
I did try that today was great
TT
Feb 09, 2012, 06:00 PM
Yo R Wee Too Lo
United States, OH, Cleveland
Joined Oct 2011
894 Posts
thanks I also checked all my batts

Quote:
 Originally Posted by gravityKills your batteries will perform better when you charge then immediately before use. One obvious reason is that charging warms them up slightly. A couple of degrees can make a huge difference.
Quote:
 Originally Posted by Magic k2 You need to measure the voltage of each lipo after charging ,only way to know dude.
4.21 when just off the charger. also 3.79 when I quit flying.
one morning it was 19F batteries lasted only a short time I had them sitting on the porch I should put the on my pocket .
thanks
TT
 Feb 10, 2012, 01:32 AM like a rock! Finland Joined Oct 2007 2,473 Posts yea I toast mine under a halogen lamp before flying