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Old Jul 10, 2012, 07:15 AM
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Joined May 2010
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charge rate for lipo

hi all

i have only ever had glow planes to date, just got my first electric and have an imax 6 charger. i have 3 cell 1800mah lipo battery.

* what is the recomended charge current, the charger has a range of .5 to 5 amps.
* should i balance everytime i charge
* how often should i dicharge the battery
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Old Jul 10, 2012, 07:37 AM
no discrimination, I crash all
ncsky's Avatar
United States, NC, Raleigh
Joined Nov 2011
272 Posts
I'm no expert but I would recommend start with charging at 1C for all your batteries. As you get more comfortable with lipo's you can charge at higher rates (depends on battery). Alot of the newer batteries you can charge at higher C rates (charge rates) which will get your batteries charged much faster. You will have to read on each battery to see what the manufacturer recommends.

For your battery above set charger to 3cell type lipo, and your charge rate would be 1.8amp (1C rate).

I don't usually discharge my batteries on any regular basis. I do this by flying the battery.

Another important thing to remember is to not drain your lipo's down to low (below 3.2 volts per individual cell).

The other thing to remember is it is always a good idea to store your lipo's at around 3.85 volts per cell. Most new chargers will have a storage mode on them. You should also charge in a lipo bag or fire safe container. Also I store them in ammo cans on concrete floor. And NEVER charge unattended (go to bed etc...)

ALOT of the horror stories about lipo's come from over/undercharging or discharging lipo's.

I balance charge every charge, but others state that you are ok with only balance charging every few charges.

There is a thread on here all about lipo charging and safety. A good idea to read up on it first.

Good Luck.
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Last edited by ncsky; Jul 10, 2012 at 07:39 AM. Reason: more information
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Old Jul 10, 2012, 07:43 AM
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United States, MN
Joined Feb 2011
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We really need a charging 101 sticky...

The max charge rate will depend on the battery but you can always charge at 1C which for an 1800 mah battery is 1.8A. Most lipo's can be charged at 3C or higher if your charger can do it. Usually the max charge rate is printed on the battery some place. Just take the C rate you want to charge at and multiply the capacity by it to get your charge rate.

You don't have to balance every time but you should at least do it every few charges, it adds a small bit of time to the charge cycle depending how out of balance your battery is. There is no reason not to balance every time though other then wanting to save those few extra min.

You should never store the battery fully charged or fully discharged as it reduces the battery life. Once discharged or if you do not use it that day you should use the storage function of your charger to set it to storage voltage (3.7V to 3.85V per cell). You should never leave a battery fully charged for more then a day or so.
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Old Jul 10, 2012, 03:08 PM
A man with too many toys
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Most LiPos have a label with the max charge rate and sometimes it’s on the manufactures web page. It’s usually stated in “C”. For 1800 MAH (or 1.8 amp hour) that’s 1.8 amps. Many of the new LiPos are rated to higher charge rate like 5C. 5C would be 1.8 * 5 = 9 amps

.
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Old Jul 10, 2012, 03:30 PM
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Lets have a contest to see how many times we can repeat the same info in different words
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Old Jul 10, 2012, 03:54 PM
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Ventura CA
Joined Aug 2007
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How about we say "Thank you" for all the answers, including those that cover the bases for those that may not be as knowledgeable as the experts!

Michael
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Old Jul 11, 2012, 03:04 AM
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Joined May 2010
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lipo charge

thank you for the answers and it was very helpful,

The batteries i have are turningly from hobby king and they have no charging information with them or on the label. the key information you gave me was the c rate.

So if i set my imax charger to charge and balance at 1.8 amps will it turn it self off at the end or do i need to pre set some max charge paremetors
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Old Jul 11, 2012, 09:23 AM
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Quote:
Originally Posted by captain wise View Post
thank you for the answers and it was very helpful,

The batteries i have are turningly from hobby king and they have no charging information with them or on the label. the key information you gave me was the c rate.

So if i set my imax charger to charge and balance at 1.8 amps will it turn it self off at the end or do i need to pre set some max charge paremetors
It will turn off at the end. The way lipo charging works is in two stages called Constant Current (CC) and Constant Voltage (CV). It starts out in CC providing the amps you specify, when the battery reaches 4.2V per cell it switches to CV providing only the amps needed to keep the voltage at 4.2V per cell. As the battery fills the amps needed to keep it at 4.2V drops, once it reaches 1/10 the amps it started at and the battery is balanced it will stop.
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Old Jul 11, 2012, 11:47 AM
no discrimination, I crash all
ncsky's Avatar
United States, NC, Raleigh
Joined Nov 2011
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No problem. Captain. Glad we could all help.

I'm getting ready to order a new charger this week (have only had 50watt one for a while) and jump into parallel charging

Good luck and have fun.
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Old Jul 12, 2012, 11:43 AM
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Colorado Springs, CO.
Joined Mar 2009
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Quote:
Originally Posted by elecfryer View Post
How about we say "Thank you" for all the answers, including those that cover the bases for those that may not be as knowledgeable as the experts!

Michael
I agree 100%. What I would like to see is a list of math formulas for all these LiPo charging questions in a sticky. I think that would go a long way towards answering alot of repeat questions.
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Old Jul 12, 2012, 03:38 PM
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Joined Mar 2004
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If your charger has max charge parameters, use them! If I am charging an 1100mah pack that I've mostly used, I set the max charge capacity at 900mah. Just in case.
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