SMALL - Telemetry SMALL - Radio
Thread Tools
Old Aug 18, 2015, 08:51 PM
omyen is offline
Find More Posts by omyen
Registered User
Joined Aug 2015
2 Posts
Help!
Batteries swelling inside urethane

Hi Everyone,

Sorry for yet another battery swelling post - I've had a search, but no-one seems to have had exactly the same issue.

I'm using LiPo batteries with about 1.48Ah capacity, they have protection circuitry on them, and I'm also using a charge chip to be extra nice to them (http://www.st.com/web/en/resource/te...CD00197120.pdf just in case you want to check it out). They're also potted in rigid urethane along with a PCB and solar panel.

The problem is that they seem to be puffing up a bit - I'm seeing bulges of about 1mm in the urethane. The previous generation of this system (with slightly different/smaller batteries, and a few other changes) was mostly fine.

Of course I'm not asking you to diagnose my problems, but does anyone have any experience in potting LiPo batteries in urethane? Or anything obvious I'm doing wrong? Or maybe it's just not a problem and totally expected?

Thanks!
omyen is offline Find More Posts by omyen
Last edited by omyen; Aug 18, 2015 at 10:43 PM. Reason: Edited to change mAh to Ah
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 18, 2015, 09:18 PM
ggcrandall1 is offline
Find More Posts by ggcrandall1
Registered User
ggcrandall1's Avatar
USA, GA, Marietta
Joined Aug 2005
7,209 Posts
Quote:
Originally Posted by omyen View Post
Hi Everyone,

Sorry for yet another battery swelling post - I've had a search, but no-one seems to have had exactly the same issue.

I'm using LiPo batteries with about 1.48mAh capacity,

Please, a link to the battery. Cell count?

they have protection circuitry on them, and I'm also using a charge chip to be extra nice to them (http://www.st.com/web/en/resource/te...CD00197120.pdf just in case you want to check it out). They're also potted in rigid urethane along with a PCB and solar panel.

The problem is that they seem to be puffing up a bit - I'm seeing bulges of about 1mm in the urethane. The previous generation of this system (with slightly different/smaller batteries, and a few other changes) was mostly fine.

Of course I'm not asking you to diagnose my problems, but does anyone have any experience in potting LiPo batteries in urethane? Or anything obvious I'm doing wrong? Or maybe it's just not a problem and totally expected?

Thanks!
Glen
ggcrandall1 is offline Find More Posts by ggcrandall1
Reply With Quote
Old Aug 18, 2015, 09:27 PM
omyen is offline
Find More Posts by omyen
Registered User
Joined Aug 2015
2 Posts
Hi Glen,

The batteries are a custom single cell from Master Instruments.

The base battery is: http://www.master-instruments.com.au...UF703450F.html

The protection circuitry added is: https://www.master-instruments.com.a...1SXP4APTC.html

And then Master Instruments adds leads and heat shrinks it.
omyen is offline Find More Posts by omyen
Reply With Quote
Old Aug 19, 2015, 03:30 AM
ggcrandall1 is offline
Find More Posts by ggcrandall1
Registered User
ggcrandall1's Avatar
USA, GA, Marietta
Joined Aug 2005
7,209 Posts
Thanks for the additional information. But even with the information you have provided I don't have a clue about the bulging you see. I suggest you go back to the manufacturer for help.

I suggest you provide the manufacturer with some good pictures of the battery. Also provide the operating voltage and current.

You might post that information here too. Someone else might have some ideas.

Glen
ggcrandall1 is offline Find More Posts by ggcrandall1
Reply With Quote
Old Aug 19, 2015, 12:46 PM
James_S is offline
Find More Posts by James_S
Registered User
United States, WA, Woodinville
Joined May 2014
2,288 Posts
Swelling is usually caused by either over-charging, over-discharging, or manufacturing defects. It's hard to say without actually looking at it. I don't see what urethane has to do with it though.
James_S is offline Find More Posts by James_S
Reply With Quote


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
For Sale Blade 300x with 3 batteries & AR7200 (PICS INSIDE) nappers Aircraft - Electric - Helis (FS/W) 0 Aug 07, 2015 09:45 PM
Discussion New 1S battery swelled when charging ohaya Batteries and Chargers 18 Mar 12, 2015 09:42 PM
Discussion Lipo Battery Swelling piper123 Batteries and Chargers 4 Jan 18, 2014 09:20 AM
Discussion Li-Po Battery Pack Swelling jet22b Batteries and Chargers 3 Oct 03, 2006 09:08 AM