Storing LiPo batteries

[GAP]

Righto can of worms time.

I am after experiences of people who have stored LiPo batteries at the storage charge level for a period of time.

As my layout is virtually been mothballed I have removed the LiPo batteries from my locos and charged them with a "storage" charge using my smart charger, so that I can transport them to the new location ( Australian regulations will apply).

Particularly interested in how long between maintenance charges I can get away with.

I know I can google the world and get all sort of advice about doing this but I would like personal or someone's friends experiences from anybody who has done this and how they did it.​

 

[Zerogee]

The only experience that I can offer is that I bought a couple of the Ansmann Li-ion packs from Rapid at least a year to eighteen months before I actually got round to using them - in that time they were just in a box, untouched and with no top-up charging. When I did get round to installing them in locos and charging them up, they were still effectively almost fully charged (it took about twenty minutes or less on a standard (not fast) charger to top them off to absolute "full"), and that may very well have been their charge level while they were in stock in Rapid's warehouse.....
So from that, I think that unless you're literally going to mothball them for years on end, they should be fine.

Jon.

 

[PhilP]

Tend to agree with Jon..
My experience is 'power tool' batteries... These can appear form the depths of a warehouse with many months of dust on them! - Quite often with a three-year-old 'manufacture' date..

All I would do (if you have the charger to do it) is give them three charge-discharge-charge cycles, when you come to bring them back into use.

 

[G-force1]

So what we're saying is, ions last eons?



H-C-D. . . .

 

[Slawman]

Store LiPos at about 3.8 volts per cell. There is usually a "storage" option on LiPo chargers, do you have that?

They don't last very long (compared with Nicads or Lead acid) overall. I have only ever got two years out of most of them, three at the outside running RC cars.

LiPos are great for a high discharge application like brushless motors in RC cars but I would not have thought to use them for a train. Why do you need LiPos?

 

[Zerogee]

Store LiPos at about 3.8 volts per cell. There is usually a "storage" option on LiPo chargers, do you have that?

They don't last very long (compared with Nicads or Lead acid) overall. I have only ever got two years out of most of them, three at the outside running RC cars.

LiPos are great for a high discharge application like brushless motors in RC cars but I would not have thought to use them for a train. Why do you need LiPos?

For the very good energy density - I have been using packs like a 14.8 volt 4S2P, 5.2 Ah capacity, 8 cylindrical cells with built-in protection board - only fractionally larger physically than an 8-cell pack of AAs with less voltage and much less capacity.
Of course for train use we're not ramming the power in and dragging it out again at massive rates, like you would with RC cars and aircraft, so i would hope the operational life would be significantly better.....

See this thread for where I'm using the pack described above.....
https://www.gscalecentral.net/threads/building-the-multi-power-loco.309298/


Jon.

 

[Greg Elmassian]

Slawman, I am impressed... most people insist on trying to store lithiums at full voltage, which is actually not good. I see that the Battery University finally updated their stuff on Lithium technology... I have an all electric car and it's interesting trading off getting more discharge cycles vs. the amount of charge vs capacity.

I'd expect a year storage, most important in storage is not at full charge and kept cool, but not frozen.

LiPo batteries are really no more suited to high discharge over LiIon as a CHEMISTRY, you can design any battery to handle more current inside. LiPo's got favor because the flexible pouch is lighter than the cylindrical cans of most LiIon, and it can be flexed/stuffed into a space.

Lithium technologies were slated for 300-500 charge/discharge cycles... as opposed to NiCads for example which can easily exceed 1000 cycles treated properly.

It's all about energy density and weight. Imagine your cell phone with nicads!!!

Greg

 

[PhilP]

It's all about energy density and weight. Imagine your cell phone with nicads!!!

Errrr.. My first cell phone DID have NiCads!!

In fact, the very first one I used was like a brick, with a 'phone on top?? - That could have been a SLA of some sort??

 

[GAP]

Store LiPos at about 3.8 volts per cell. There is usually a "storage" option on LiPo chargers, do you have that?

They don't last very long (compared with Nicads or Lead acid) overall. I have only ever got two years out of most of them, three at the outside running RC cars.

LiPos are great for a high discharge application like brushless motors in RC cars but I would not have thought to use them for a train. Why do you need LiPos?

Yes I have a storage option on my charger which is what I have used to give them their storage charge.
The LiPos I have are "Graphene" type recommended by a model plane enthusiast at work supposedly give better output compared to standard ones.
1 x 4000mAHr and 1x5200mAHr they are charge at 1/10C ie 0.4A and 0.5A respectively, the smaller one runs a single motor (Connie) while the larger runs 3 connected in parallel (Shay). I ran AA NiMH in the shay and they lasted about 1.5-2 hours run time the LiPos I have not been able to get down to cutoff so I do not know jow long they will give but I did have over 3 hours with no noticeable sign of performance degradation.

 

[Slawman]

Yes I have a storage option on my charger which is what I have used to give them their storage charge.
The LiPos I have are "Graphene" type recommended by a model plane enthusiast at work supposedly give better output compared to standard ones.
1 x 4mAHr and 1x5.2mAHr they are charge at 1/10C ie 0.4A and 0.5A respectively, the smaller one runs a single motor (Connie) while the larger runs 3 connected in parallel (Shay). I ran AA NiMH in the shay and they lasted about 1.5-2 hours run time the LiPos I have not been able to get down to cutoff so I do not know jow long they will give but I did have over 3 hours with no noticeable sign of performance degradation.

When I store mine I put them on the store charge and if I get really excited halfway through winter I put them on a store charge cycle again but they rarely need a top-up. If you have a good quality charger then I would rely on that to set them up around 3.8v per cell. Discharging them in my application is very hard on them (you always run flat out until they cutout and they are always very warm) so you may get a lot more life out of them for Locos than with RC cars....

From my experience I never leave them in a fully charged state for more than a few hours or they will start to go puffy.

Do you have a low voltage cutout protection in your setup? Discharging below a certain voltage will kill them as well (straight away).

 

[ge_rik]

No direct experience of storing lipos, other than having three lipo powered locos which sit on my shelves for varying amounts of time with various rates of charge. However, I recently had to replace a 3 cell lipo (with a puffy cell) with three 18650 li-ion cylindricals which I had bought as a job lot just over two years ago. All three of the 18650s were reading 3.6v, despite me not having touched them since I bought them. This suggests that, provided you keep them at their storage voltage, they should survive ok. As far as I understand, the chemistry of lipos and cylindrical li-ions is sufficiently similar for them to be treated the same as regards storage.

Rik

 

[PhilP]

Yes I have a storage option on my charger which is what I have used to give them their storage charge.
The LiPos I have are "Graphene" type recommended by a model plane enthusiast at work supposedly give better output compared to standard ones.
1 x 4mAHr and 1x5.2mAHr they are charge at 1/10C ie 0.4A and 0.5A respectively, the smaller one runs a single motor (Connie) while the larger runs 3 connected in parallel (Shay). I ran AA NiMH in the shay and they lasted about 1.5-2 hours run time the LiPos I have not been able to get down to cutoff so I do not know jow long they will give but I did have over 3 hours with no noticeable sign of performance degradation.

Rik,
A couple of "m's" seem to have sneaked into your battery capacities..
Not sure your loco's would even move with 4mAHr and 5.2mAHr batteries?

 

[No72]

I have several Li-ion battery packs and 18650 cells unused since 2014. Just yesterday I thought I'd have a look at them prepared to have to replace them. All of them were up to spec with an average cell voltage around 3.5v.... They have been stored inside in a climate controlled environment though.

 

[GAP]

When I store mine I put them on the store charge and if I get really excited halfway through winter I put them on a store charge cycle again but they rarely need a top-up. If you have a good quality charger then I would rely on that to set them up around 3.8v per cell. Discharging them in my application is very hard on them (you always run flat out until they cutout and they are always very warm) so you may get a lot more life out of them for Locos than with RC cars....

From my experience I never leave them in a fully charged state for more than a few hours or they will start to go puffy.

Do you have a low voltage cutout protection in your setup? Discharging below a certain voltage will kill them as well (straight away).

My ESCs have a LiPO cut out feature

 

[GAP]

Rik,
A couple of "m's" seem to have sneaked into your battery capacities..
Not sure your loco's would even move with 4mAHr and 5.2mAHr batteries?

Corrected

 

[Thomas Lambo]

Hi Gap,

I have over 15 years of experience using Lipo batteries (RC Airplanes and most recently racing Fast Electric Straight Line boats.... using just about every size Lipo battery). Needless to say, I've spent years figuring out how to prolong battery life while squeezing every once of power out of them

So, I can tell you from experience that Slawman is spot on target with his recommendations.

Also, if I could make only one recommendation to Lipo users it's to buy an "Intelligent/Smart" charger (I know you have one).

I'll be using battery power in all my trains if I ever finish the Railroad

 

[PhilP]

Also, if I could make only one recommendation to Lipo users it's to buy an "Intelligent/Smart" charger (I know you have one).

Google imax B6..
In UK look for one with suitable leads, many a copies, but seem good..

 

[GAP]

Hi Gap,

I have over 15 years of experience using Lipo batteries (RC Airplanes and most recently racing Fast Electric Straight Line boats.... using just about every size Lipo battery). Needless to say, I've spent years figuring out how to prolong battery life while squeezing every once of power out of them

So, I can tell you from experience that Slawman is spot on target with his recommendations.

Also, if I could make only one recommendation to Lipo users it's to buy an "Intelligent/Smart" charger (I know you have one).

I'll be using battery power in all my trains if I ever finish the Railroad

These are the ones I have, I run them off old ATX computer power supplys modified to be used as bench supply.

Chargers
https://hobbyking.com/en_us/turnigy...ncer-charger-lihv-capable.html?___store=en_us

https://hobbyking.com/en_us/turnigy-accucel-6-50w-6a-balancer-charger-w-accessories.html

PSU
http://www.instructables.com/id/ATX-->-Lab-Bench-Power-Supply-Conversion/

 

[Thomas Lambo]

GAP, your chargers are fine....I have several HK units myself. I buy from their USA warehouse to keep shipping costs down.

Hobby King is a good source for batteries and/or anything RC (very competitive pricing). I've got a half dozen of their Airplanes as well.

As you probably know, the higher end chargers will charge almost any chemistry battery, as well as include a large selection of connectors.