How would store your battery for 5 months?

[Neverlost99]

Luna Eclipse with a 874 whr battery that is in the frame
Battery will be left at 40-50%
House AC at 78 degrees and humidity control
We will be gone for 5 months
Is there anything to worry about?
Should I put a Bluetooth smoke detector or security camera on the bike?
Should I just take the battery with me to North Carolina and leave it inside instead?
I can’t take the bike ( small car) just the battery.
The cells are LG and supposed to be high quality but since I am a newbie and don’t want to be responsible for leaving a battery unattended in a wood frame building if it’s dangerous.

 

[AHicks]

The wife and I are snowbirds, commuting from Florida to Michigan and back every 6 months. We have bikes on each end, with a total of 5 bikes beteen us. I can share I like the batteries at around 50% as well (not THAT critical though), and that all I do is pull the battery from the bike and put it on the workbench. I do this to prevent any residual drains on the battery - like an internal clock for instance. Been working fine for us so far (2 years). Batteries not loosing any charge to speak of in our absence.

 

[Taylor57]

I take mine off the bikes after I run them to 50% and store on a pillow in my office guest chair at 78 Fahrenheit. No problems so far. I also sell insurance and have a comprehensive homeowners policy

 

[PatriciaK]

I take mine off the bike (try to have it down to about 60%) and store it on the kitchen counter. NC house air con set at 80, WA house heat set at 55. Never had a problem... Also have comprehensive HO insurance .

We're gone for 3 months at a time...

 

[Neverlost99]

Thanks guys. Great response

 

[DaveMatthews]

Agree with the other posters. That said, my Giant charger has a storage mode that sets the battery at 60%.
Doubt there's much difference.

 

[tomjasz]

Batteries not loosing any charge to speak of in our absence.

I had an EM3ev battery, never used stored at 3.8v/cell. It discharged to low to recover. Probably a BMS failure but still… My former shop gifted a new pack when I resigned.

 

[Gionnirocket]

I had an EM3ev battery, never used stored at 3.8v/cell. It discharged to low to recover. Probably a BMS failure but still… My former shop gifted a new pack when I resigned.

3.8v is a little on the high side... But it also depends on how long you store it.
Samsung recommends 3.6v

 

[tomjasz]

3.8v is a little on the high side... But it also depends on how long you store it.
Samsung recommends 3.6v

When I trained to be a certified shipper 3.8 was the suggested level.

3.8v is a little on the high side... But it also depends on how long you store it.
Samsung recommends 3.6v

35E 3.49V ~ 3.69V Charging voltage range
50E 3.43V ~ 3.63V

In fact it varies between versions and brands. When I trained for certification originally it was 40% later second session it was 30%.

See batterybro.com for a discussion comparing several cells.

Exact storage is rated by time and temperature if we want to split hairs.

How to store 18650 batteries safely

Automated warehouse for small electronic parts What is the best way to store an 18650 battery? In this blog post, rather than do my own testing - I will rely on the specification sheets provided by Panasonic, Samsung, and LG. We'll look at the storing section of these spec sheets, and break down...

batterybro.com

 

[Gionnirocket]

When I trained to be a certified shipper 3.8 was the suggested level.

35E 3.49V ~ 3.69V Charging voltage range
50E 3.43V ~ 3.63V

In fact it varies between versions and brands. When I trained for certification originally it was 40% later second session it was 30%.

See batterybro.com for a discussion comparing several cells.

Exact storage is rated by time and temperature if we want to split hairs.

How to store 18650 batteries safely

Automated warehouse for small electronic parts What is the best way to store an 18650 battery? In this blog post, rather than do my own testing - I will rely on the specification sheets provided by Panasonic, Samsung, and LG. We'll look at the storing section of these spec sheets, and break down...

batterybro.com

I concur.. Definitely brand/model specific.
The common specs you show are below 3.8v, more so if you take the mean of the range.
I typically follow manufacturer specs over training as sometimes instructors can have some personal experience that skew

 

[m@Robertson]

Agree with what AHicks and others said. The key is to ensure there are no drains on packs that you are unaware of. The owner of Luna has said he stays away from Bluetooth BMS' specifically because of the tiny drain they put on the pack (and this is why I stay away from Bluetooth BMS as well) so you're safe with regard to the pack draining itself on its own.

Ideal storage is around 60%. Partly because a punctured cell at 100% goes boom and one at 60% goes fizzzzzz. There is more to it than that but rest assured its well known/documented that storage at 100% degrades the cells, so never do that.

My daughter and son-in-law just returned from living abroad for a year (work) and the bikes are fine and still at 60% as they left them. I did have them get someone to check monthly by plugging in a charger I had them dial to 60%, but only a few months in their checker sadly passed away so the packs sat for most of the year and came out fine.

 

[Mr. Coffee]

I have a large (6 by 8 feet) shower, all concrete or tile with a galvanized steel ceiling. If I am not home I park the batteries there charged between 40 and 60.

 

[tomjasz]

Agree with what AHicks and others said. The key is to ensure there are no drains on packs that you are unaware of. The owner of Luna has said he stays away from Bluetooth BMS' specifically because of the tiny drain they put on the pack (and this is why I stay away from Bluetooth BMS as well) so you're safe with regard to the pack draining itself on its own.

Good Hicks Al, crazy Hicks, Luna. IF the BT pack has an off switch there's no drain. That said a failed BT BMS on an EM3ev DID drain. New pack, stored is checked every other week while not using and I've seen ZERO drain. BT BMS from EM3ev on a pack I built using...

 

[FrankR]

I take mine off the bikes after I run them to 50% and store on a pillow in my office guest chair at 78 Fahrenheit. No problems so far. I also sell insurance and have a comprehensive homeowners policy

I, too, checked, and I have a comprehensive homeowner's policy that covers my bike.

 

[PedalUma]

I would take it down to 30% and set it on the fireplace grate. I like the tub idea. But Li and water do not mix. Stuff happens. A neighbor had an upstairs leak develop while he was gone for six weeks.

 

[Gionnirocket]

I think the refrigerator would be an ideal place if you can vacuum seal it to keep out humidity.
Also placing a rack of ribs above it in case there is a thermal runaway event could yield some tasty results.

 

[PedalUma]

Instant BBQ
I was just thinking.. An old toilet tank from a junkyard would be about ideal for storing batteries.

 

[JES2020]

Should I put a Bluetooth smoke detector or security camera on the bike?

I would do both. It's not worth loosing sleep over.
Also for safety of the battery, I would leave it at 70% charge for that length of time.
If it drains down too far , it is unrecoverable.

 

[Jason Knight]

There is so much noodle-doodle nonsense about the batteries on these bikes. Lands sake they're 18650 Lithium-Ion, same batteries used in laptops. IF you have a problem it's not the batteries, it's the controller.

Even though I'm not even a year into e-biking, I know the 18650 quite well from working with laptops. Hell my 12 cell for my old beach cruiser's headlight was built from cells recycled from laptop batteries.

These things are tough. The 12 cell pack I made from scrap has sat entire winters without being powered on in an unheated garage at temperatures ranging from -11F to 120F+, and still held almost 90% charge from full, without ever losing capacity.

So long as you don't have anything attached to suck on its power and it doesn't run completely flat, you SHOULD be fine. Unless it's the cheapest cells on the planet, there is no reason for it when not connected to lose more than 3-4% a month, without any damage to its max capacity.

Beyond that these crazy claims of battery storage methods are little more than placebo BS. If by specification they have an operating range of -10F to 185F, I really doubt you need to worry about temp when not under load.

The only real issue I would see is if the controller in the battery is too complex for its own good, and you drain it completely flat. Like... flatter than the level at which the controller turns off the flow to protect itself. Beyond that, I call bullcookies on most of these "tricks".

Give it enough charge to keep the built-in controller happy during your downtime, anything else is rubbish.

"Find the enemy and shoot him down, anything else is rubbish" -- Manfred Albrecht Freiherr von Richthofen

 

[JES2020]

There is so much noodle-doodle nonsense about the batteries on these bikes. Lands sake they're 18650 Lithium-Ion, same batteries used in laptops. IF you have a problem it's not the batteries, it's the controller.

Even though I'm not even a year into e-biking, I know the 18650 quite well from working with laptops. Hell my 12 cell for my old beach cruiser's headlight was built from cells recycled from laptop batteries.

These things are tough. The 12 cell pack I made from scrap has sat entire winters without being powered on in an unheated garage at temperatures ranging from -11F to 120F+, and still held almost 90% charge from full, without ever losing capacity.

So long as you don't have anything attached to suck on its power and it doesn't run completely flat, you SHOULD be fine. Unless it's the cheapest cells on the planet, there is no reason for it when not connected to lose more than 3-4% a month, without any damage to its max capacity.

Beyond that these crazy claims of battery storage methods are little more than placebo BS. If by specification they have an operating range of -10F to 185F, I really doubt you need to worry about temp when not under load.

The only real issue I would see is if the controller in the battery is too complex for its own good, and you drain it completely flat. Like... flatter than the level at which the controller turns off the flow to protect itself. Beyond that, I call bullcookies on most of these "tricks".

Give it enough charge to keep the built-in controller happy during your downtime, anything else is rubbish.

"Find the enemy and shoot him down, anything else is rubbish" -- Manfred Albrecht Freiherr von Richthofen

True , they are like the batteries in laptops...but laptops don't have so damn many !

Personally I would ALWAYS advise in the direction of maximum safety. I wouldn't want to be responsible for someone's fire, OR WORSE .
It's bad karma man... something S.T.E.s are unfamiliar with.