Logo
Builders' Plan Gallery  |  Hip Pocket Web Site  |  Contact Forum Admin  |  Contact Global Moderator
September 22, 2019, 01:36:23 AM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with email, password and session length
 
Home Help Search Login Register
Pages: [1]   Go Down
Print
Author Topic: lipo batteries  (Read 861 times)
0 Members and 1 Guest are viewing this topic.
wingnut
Nickel Member
*

Kudos: 0
Offline Offline

United Kingdom United Kingdom

Posts: 5

Topic starter


Ignore
« on: April 18, 2015, 12:23:41 PM »

hi folks
i would like to ask a question please
i have built my first plane but i have a problem with my lipo batteries i bought 2 1500mha 11.1v lipos
and an imax b6 charger new last xmas and both batts were fine i have charged each one once since then
after a few months laying dormant i tried them in my plane but they were both low on power so i charged
them both up but they still lacked power
i get an over voltage error and they wont charge at 11.1v only at 7.4
and one of them now has a bulge in it i have now bought a new charger and one new lipo but i do not
want to try and charge my old batts on my new charger
is it possible that either my old charger or a faulty esc could have damaged both of them
any advice would be appreciated
regards - AL
Logged
mjmccarron
Silver Member
****

Kudos: 5
Offline Offline

United States United States

Posts: 149




Ignore
« Reply #1 on: April 18, 2015, 12:53:55 PM »

Al,
The subject of LiPo batteries is both lengthy and diverse. I believe that your problem is in the batteries and not the charger. LiPo batteries should not be stored at full charge and if over discharged even by self discharge during storage, they become very unstable. The bulge you describe is the first sign of trouble. The next sign is usually the cell bursting and emitting smoke, gas and usually flames.

Rather than write a lengthy article here on the forum, I would like to refer you to two links which should help to shed light on the workings of LiPo's and if I can help you to understand any of it please don't hesitate to ask. In the mean time, I would not try to charge those batteries. The cost has gone down enough to make replacing them a viable option.

Mike

http://www.rchelicopterfun.com/rc-lipo-batteries.html

http://batteryuniversity.com/learn/
Logged

Light travels faster than sound. That's why some people seem bright until you hear them speak.
wingnut
Nickel Member
*

Kudos: 0
Offline Offline

United Kingdom United Kingdom

Posts: 5

Topic starter


Ignore
« Reply #2 on: April 18, 2015, 01:22:01 PM »

hi mike
thanks for the  info much appreciated
regards - AL
Logged
Balsa Ace
Gold Member
*****

Kudos: 25
Offline Offline

Canada Canada

Posts: 466


FAC Member



Ignore
« Reply #3 on: April 18, 2015, 01:33:36 PM »

Hello & welcome,Al.

Scott
Logged

Hawker Sea Fury FB.11
HMCS Magnificent
VF-871   Royal Canadian Navy
wingnut
Nickel Member
*

Kudos: 0
Offline Offline

United Kingdom United Kingdom

Posts: 5

Topic starter


Ignore
« Reply #4 on: April 18, 2015, 05:05:33 PM »

hi scott
thank you for the welcome
hope to have a chat with some of you guys on here sometime
im kind of new to rc planes i had a couple years ago but had no luck
with the flying although i did enjoy building
regards - AL
Logged
Robmoff
Silver Member
****

Kudos: 3
Offline Offline

United Kingdom United Kingdom

Posts: 219




Ignore
« Reply #5 on: April 18, 2015, 07:35:00 PM »

I am just wondering if your charger is a genuine IMAX, there are a lot of clones available here. Some might be OK but I had one that was a positive menace. Inconsistent charging, and balancing would actually throw the cells MORE unbalanced, which can be very dangerous. So does yours have the holographic logo on the back?
Logged

Never underestimate the innate hostility of inanimate objects.
wingnut
Nickel Member
*

Kudos: 0
Offline Offline

United Kingdom United Kingdom

Posts: 5

Topic starter


Ignore
« Reply #6 on: April 19, 2015, 03:54:40 AM »

hi
i have three of these same chargers now and all of them have a small holographic disc with qc passed on them on the reverse
but i am sure they are not all genuine as the sellers i have bought them from on ebay sell a lot of the cheaper chinese items so it would be hard to tell as everything nowadays is easily copied
buying a capacity controller next week so i can tell when the cells are unbalanced (chinese apparently) lol
regards - AL

Logged
cvasecuk
Gold Member
*****

Kudos: 5
Offline Offline

United Kingdom United Kingdom

Posts: 254



Ignore
« Reply #7 on: April 19, 2015, 05:02:52 AM »

I wonder if your original cells were only 2 cell? Trying to charge 2s lipos as if they are 3s would certainly damage them in the way you indicated. If they are 3s then one of the cells might be U/S but that is unlikely on both!
Ron

Logged
wingnut
Nickel Member
*

Kudos: 0
Offline Offline

United Kingdom United Kingdom

Posts: 5

Topic starter


Ignore
« Reply #8 on: April 19, 2015, 10:08:51 AM »

hi ron
they are 3 cell 1500mha 11.1v after i tried to charge them i checked them with the multimeter
the cell voltages were battery 1 c1=2.62v c2=4.67v c3=4.67v
and battery 2 (the one with the bulge) c1=dead c2=3.74v c3=3.75v
the batteries worked fine before i left them lying i did not know that you cant leave them for any
length of time without discharging them
costly mistake i wont let that happen again
regards - AL
Logged
Pages: [1]   Go Up
Print
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!