RC India

RC Equipments => Batteries and Chargers => Topic started by: arvind kapoor on December 09, 2009, 09:40:18 PM



Title: LIPO with more MAmps
Post by: arvind kapoor on December 09, 2009, 09:40:18 PM
Hi ,

I want to buy 3.7V Lipo with more that 1000MAmp for my 4CH Heli.
can any one suggest me is it available or not.
I am using 3.7V /1000 Mamp Lipo but it is not giving good flight time and laso battery life is too short (20 flights ) approx i think

Any solution  ???

Arvind


Title: Re: LIPO with more MAmps
Post by: ujjwaana on December 09, 2009, 10:26:53 PM
Jugaard ...buy a 2S1P 1000mAH LiPo, Dissect it and disconnect the individual LiPo cells. You are landed with 2 nos of 1000mAH 1S1P LiPo. Seniors wouldn't that work ?

And for your battery lifetime issue, have you tried breaking in the battery (4-5 cycle of charge-discharge) before the maiden flight ?

Gerd Giese of Elektromodellflug.de recommends, based on his experience of testing hundreds of packs, the follwing slightly more elaborate procedure to remove the discharge inhibitor:

0.5C charge - 1C discharge to 3.5V/c
0.5C charge - 2C discharge to 3.5V/c
1.0C charge - 3C discharge to 3.3V/c
1.0C charge - full power use

<from : http://www.parkjets.com/building.html>

All the best!


Title: Re: LIPO with more MAmps
Post by: anwar on December 10, 2009, 12:01:29 PM
If a lipo is dying in 20 flights, that needs to investigated on its own.  Remember that we all tend to get carried away in terms of flying time, and in the process end up abusing lipos.

Lipos will die a quick yet painful death (they bulge out) if you over discharge them.  There have been multiple threads here on how to care for them properly (like this one http://www.rcindia.org/batteries-and-chargers/taking-care-of-lipos/).  Make sure you routinely only draw about 80% of the available mAH of a battery, and time your flights to stop at the point.  If you are unsure how to to this even after reading the above thread, please ask.

If you are looking for more flight time, add the number of batteries you have, and do not try to go for ones with very large mah rating.  They get heavier with capacity, and would affect the AUW of the plane. 

One more thing to note...  8 to 10 minutes is a good flight duration. If you are getting that far, then settle for it. Take a break, put in a new pack and fly for another 8 to 10 minutes.  As an activity that is to be done with a concentrated mind, long flights without breaks in the middle are not recommended.

Finally, as Ujjwal said, you can break down large mah 2cell lipos to get two 1cell packs.  Not recommended, so if you are doing this, do this with utmost caution and remember that you may end up with a battery that is too heavy for your aircraft.


Title: Re: LIPO with more MAmps
Post by: tg on December 10, 2009, 12:37:48 PM
Jugaard ...buy a 2S1P 1000mAH LiPo, Dissect it and disconnect the individual LiPo cells. You are landed with 2 nos of 1000mAH 1S1P LiPo. Seniors wouldn't that work ?

And for your battery lifetime issue, have you tried breaking in the battery (4-5 cycle of charge-discharge) before the maiden flight ?

Gerd Giese of Elektromodellflug.de recommends, based on his experience of testing hundreds of packs, the follwing slightly more elaborate procedure to remove the discharge inhibitor:

0.5C charge - 1C discharge to 3.5V/c
0.5C charge - 2C discharge to 3.5V/c
1.0C charge - 3C discharge to 3.3V/c
1.0C charge - full power use

<from : http://www.parkjets.com/building.html>

All the best!

Plus have medical, house insurance and a fire extinguisher at hand.


Title: Re: LIPO with more MAmps
Post by: arvind kapoor on December 10, 2009, 05:58:43 PM
Hi All,

Thanks for all VVVV usefull inputs.
I think I used battery to drain to 100% many times, that could be the reason.
Thanks for pointing to the thread, it will save my money by spending less on battery after following these instructions  {:)}

Regarding JUGAARD..... I have seen many videos of Lipos getting blasted so I am little affraid of doing what is suggested  >:D





Title: Re: LIPO with more MAmps
Post by: ujjwaana on December 11, 2009, 02:03:45 AM

Plus have medical, house insurance and a fire extinguisher at hand.

Hey TG, was the comment on split opening the batteries or the breaking-in process as I quoted from Parkjets.com ?




Title: Re: LIPO with more MAmps
Post by: vinay on December 11, 2009, 08:10:54 AM
Plus have medical, house insurance and a fire extinguisher at hand.

Tg, Its not that dangerous to play with Lipos. I do agree they flame up, when they are over charged, abused(crashes) or when people try to charge puffed ones, Other wise they are safe to work on, I really did split a FULLY Charged 3 Cell Lipo but I was VERY CAREFULL. that I didnt short anything when opening it up, small shorts happened twice when opening due to blade touching the contacts occasionally for milliseconds ;D. If you work on a discharged Lipo its still better. I also created a single cell Lipo out of the better ones with longer contacts, but the other 2 lipos had shorter contacts so I left them as it is. Below is a thread that I opened up in another site regarding the same.

http://www.wattflyer.com/forums/showthread.php?t=52063