Toronto Electric Model Aviation Club Forum

Toronto Electric Model Aviation Club (TEMAC) => General Discussion => Topic started by: Frank v B on October 09, 2018, 09:22:06 pm

Title: Winter storage- lipos
Post by: Frank v B on October 09, 2018, 09:22:06 pm
Could someone please post an idiot's guide on "How to store lipo's for winter"... in plain english with words no more difficult than "see Spot run"*.  This is both for new members and old ones like me. ;D

Frank

* that should pretty well eliminate Andy on two counts- he flies in winter and is a walking dictionary.... not containing any simple words. ;) ;) 8)
Title: Re: Winter storage- lipos
Post by: mawz on October 09, 2018, 09:36:49 pm
Discharge to storage voltage - 3.8-3.85V per cell. Most chargers will have a discharge setting to do this. Note if they're already discharged beyond that, you may need to charge first.

Store in a secure, contained storage, preferably fireproof. A BatBox or ammo can is good, or in your lipo bags. If using an ammo can, do make sure it's not airtight. Don't store near flammable items (especially not that half a jug of glow fuel that's been sitting since you discovered the joy of Lipo's)
Title: Re: Winter storage- lipos
Post by: bweaver on October 09, 2018, 11:15:38 pm
The article I always refer to found at https://www.rchelicopterfun.com/lipo-batteries.html, is the most informative I have read on the subject of 'lipos do's and don'ts', including guidance on storage and charging practices. 

I think it is a must read, even you could understand @Frank v B . (Because I can - I think)
Title: Re: Winter storage- lipos
Post by: Andy Hoffer on October 10, 2018, 08:59:50 am
The article I always refer to found at https://www.rchelicopterfun.com/lipo-batteries.html, is the most informative I have read on the subject of 'lipos do's and don'ts', including guidance on storage and charging practices. 

I think it is a must read, even you could understand @Frank v B . (Because I can - I think)

Excellent article @bweaver .  But I do fear for the impact on @Frank v B due to all the multi-syllable words.  8)

ANdy
Title: Re: Winter storage- lipos
Post by: bweaver on October 10, 2018, 09:14:01 am
Re: Excellent article @bweaver .  But I do fear for the impact on @Frank v B due to all the multi-syllable words.  8)

ANdy


There are pictures in the article too.  ;D
Title: Re: Winter storage- lipos
Post by: Andy Hoffer on October 10, 2018, 11:31:58 am
Re: Excellent article @bweaver .  But I do fear for the impact on @Frank v B due to all the multi-syllable words.  8)

ANdy


There are pictures in the article too.  ;D


Whew!!  Thanks @bweaver . I feel much better now!!  I'm sure @Frank v B  will too!!  8)

Andy
Title: Re: Winter storage- lipos
Post by: AlexShao on October 10, 2018, 02:31:57 pm
Usually, I use the storage mode to charge all the LiPo batteries every month.
Title: Re: Winter storage- lipos
Post by: MarcV on October 10, 2018, 10:39:26 pm
As I understand it, the lower the charge level the better for storage.
I've stored my lipos as low as 5 or 10% (3.7V/cell) over the winter.
The disadvantage of that is that if you have a poor quality lipo, it will self discharge to below 0% over the winter and be damaged.
Or if you don't use that lipo the next summer, it will eventually self discharge to below 0%.

I now store my lipos at the 25% level (3.75V/cell) over the winter.
The lipos that I stored over the winter at 25% and don't use during the summer,still have enough charge to make it through the next winter.

How much better it is for the lipo to be stored at the 25% (3.7V/cell) level compared to the 50% level (3.80 to 3.85V/cell) I don't know.

Marc
Title: Re: Winter storage- lipos
Post by: mawz on October 11, 2018, 01:01:43 pm
As I understand it, the lower the charge level the better for storage.
I've stored my lipos as low as 5 or 10% (3.7V/cell) over the winter.
The disadvantage of that is that if you have a poor quality lipo, it will self discharge to below 0% over the winter and be damaged.
Or if you don't use that lipo the next summer, it will eventually self discharge to below 0%.

I now store my lipos at the 25% level (3.75V/cell) over the winter.
The lipos that I stored over the winter at 25% and don't use during the summer,still have enough charge to make it through the next winter.

How much better it is for the lipo to be stored at the 25% (3.7V/cell) level compared to the 50% level (3.80 to 3.85V/cell) I don't know.

Marc

That's not the case, storing discharged lipo's is just as bad for them as storing fully charged lipos.

You want to as close to 50% charge as possible for a long shelf life. 25% is not terrible for them, but you'll get better results and a longer lifespan at 50%.
Title: Re: Winter storage- lipos
Post by: Frank v B on October 11, 2018, 06:31:04 pm
Hey, @Andy Hoffer,

You can now translate Mawz's simple English instructions into a Websterian masterpiece:

Please translate the following:
Discharge to storage voltage - 3.8-3.85V per cell. Most chargers will have a discharge setting to do this. Note if they're already discharged beyond that, you may need to charge first.

Store in a secure, contained storage, preferably fireproof. A BatBox or ammo can is good, or in your lipo bags. If using an ammo can, do make sure it's not airtight. Don't store near flammable items (especially not that half a jug of glow fuel that's been sitting since you discovered the joy of Lipo's)


Frank ;)
Title: Re: Winter storage- lipos
Post by: MarcV on October 16, 2018, 01:29:41 am
Adam, do you have the source of information for the 50% storage value?

I got my information from Sony's Lithium Ion Rechargeable Batteries Technical Handbook.  I enclose the relevant section that shows that storing a battery at "0% (3.3V)" is slightly superior then at "50% (3.8V)".

This is also backed up by personal correspondence with Walter Van Schalkwijk Ph.D. (who's written a few books on lithium ion batteries) and is a user of my battery analyzers.

Marc