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How to charge lipo's at the field

#1
I have been trying to find a solution to charging my lipos at the field in a quick amount of time. i have used an old 12v lead acid battery but it took almost 3 hours to charge a 4s 3000mah battery. I need something that is fast and will charge many batteries. I was looking at a few options.

https://www.amazon.com/dp/B018K7HXHC/?tag=lstir-20

https://www.amazon.com/dp/B07775VRFR/?tag=lstir-20

I was also looking at a generator but it is only $100 so maybe it is not as good as other ones that are a lot more expensive

https://www.walmart.com/ip/Sportsma...75035&wl11=online&wl12=21174255&wl13=&veh=sem
 

CarolineTyler

Well-known member
#2
The two batteries would easily take the load of charging I would expect, but neither state the capacity and without that you would have no idea as to how many flight batteries you could charge.
The generator is 800w continuous load so that is 6.6amps at 120volts - you should be able to charge most flight batteries from it.
 

Hai-Lee

Old and Bold RC PILOT
Mentor
#3
There safety rules when it comes ot recharging LiPos.
Never charge a hot battery.
Never leave a battery on charge unattended.
Fast charging generates heat and shortens battery life
Excessive discharge destroys batteries

I fly quite a lot and have a number of chargers BUT I cannot monitor my batteries on charge and fly at the same time,
At the field I do not have access to anything to fight a battery that catches fire and it also could endanger other users at the field.

My approach is to have a number of batteries, sufficient for a full mornings flying all charged. After flight I leave the batteries in a safe location until cool prior to packing in the discharged container. At home I check each battery and place the batteries on the charger and only charge at a 1C rate to reduce excessive heat build up. (normal charge time is around 1 hour).

When I charge a battery I do NOT ever use fast charging and ALWAYS balance charge!

After charging the batteries are left to cool down prior to packing away for tomorrows flying!

Being impatient with the charging of batteries will cost you money in lost and unreliable batteries. It could also have you labelled as "Smokey the Bear" after a few LiPo fires!

Think safety and be safe always!

Have fun!
 

Chuppster

Active member
#4
I took apart some old laptop batteries and made a huge 4s 15000mah pack that I charge up at home and take to the field with me. I 3d printed an 18650 holder for all the cells. If you can get your hands on some old laptops that may be the best option for you.

I should mention that I power my battery charger off of it.
 

Bricks

Active member
#5
Actually it sound like your charger may not have enough output to charge your batteries faster or you need to kick up your C rating . We are learning more and more that Lipo batteries can take a much faster charging rate then was first presumed and not hurt the battery. I normally charge my batteries at 3C and have not noticed any unusual degradation in there ability to hold a full charge or flight times. As batteries get more cycles on them the resistance starts to go up there is no way around this, high resistant batteries will start taking longer to charge.

I have a friend that runs a lot of 6S 5000MAH batteries his set up will recharge three batteries in a little more then 15 minutes from running them down to 40%, he has been doing this for the last 4 years and no noticeable degradation in his batteries.