Keeping batteries healthy during the cold winter

[newbie2011]

Hello All, I'm after some advice regarding my battery. I have to say despite loving my bike I'm not very good at using it during the winter. It is stored outside in the summerhouse where it's dry but quite cold. I'm wondering how I should ensure the battery is kept healthy during the winter and would be grateful for any advice.
I've kept it fully charged. Is there anything else I need to consider.
Many thanks
Newbie

 

[NRG]

Dont let it freeze! Bring it indoors and put it in an unheated under-stairs cupboard or similar...the best charge state for long term storage is approx 40% of full charge, but a few months after a full charge should be OK.

 

[amigafan2003]

What chemistry is it?

 

[Kudoscycles]

The Lithium Manganese,Ion or Polymer are more fussy than the Lithium Phosphate. We have some bikes at work that were delivered prior to our selection of LifePo4 and they need recharging more often and kept at about 20deg C....the LifePo4 has a very low self discharge rate and can accomodate considerable temperature range(it was originally developed for weather stations)-all Lithium batteries do not like to be stored fully charged or flat,ideally keep between 80-20%.
Dave
KudosCycles

 

[flecc]

The key thing is not to leave it for three months or more without a charge, preferably charge every two months if completely out of use.

The lithium batteries of all types that we use have internal circuitry management (BMS), which on most is on all the time using a tiny amount of current. If left for a long time without recharging, the battery's cells can be discharged to unrecoverable levels eventually.

 

[newbie2011]

Thank you

Thank you all for your advice. The batteries are lithium polymer with compound cathodes.

 

[flecc]

Thank you all for your advice. The batteries are lithium polymer with compound cathodes.

They are the most popular with the manufacturers at present and perform well compared with the earlier simple cathode types.

 

[avronb]

Any advice on storing SLA batteries during the lower use winter months?they are at present stored in the house at about 65f

 

[flecc]

Any advice on storing SLA batteries during the lower use winter months?they are at present stored in the house at about 65f

No special advice other than charge at least once every three months if out of use. For example, the Quickstart that has an 18 Ah lead acid battery within, I top-up charge every two months all year round. I don't worry about it's storage temperature though it is stored in the coolest room in my home.

I've had it several years, lost count now, but it still spins up any size of petrol or diesel car or van engine.

 

[morphix]

Just as an aside to this thread..I've noticed the cold weather this month has really affected my Lithium-Ion battery, performance dropped noticeably with the temp..as it's getting frosty now I've stopped using it for the last few weeks and the battery was fully charged so I guess I need it to run it down a bit.. This is my first winter with an electric bike..I've only had my bike coming up to a year this Feb... I guess I should go on a long ride to celebrate

 

[flecc]

Just as an aside to this thread..I've noticed the cold weather this month has really affected my Lithium-Ion battery, performance dropped noticeably with the temp..as it's getting frosty now I've stopped using it for the last few weeks and the battery was fully charged so I guess I need it to run it down a bit.. This is my first winter with an electric bike..I've only had my bike coming up to a year this Feb... I guess I should go on a long ride to celebrate

It will already have run down quite a bit over those weeks of no use, since the internal BMS uses some current all the time. The only exception to this is the Panasonic unit battery which has a sleep mode, shutting down the BMS after about two weeks.

In any event, don't forget to charge the battery at least once every three months it's out of use, and preferably every two months to make sure. If you don't the BMS will flatten it and can destroy the cells.

 

[indalo]

For the first time ever, my battery has failed to produce all 5 lights on the press-and-hold test. Only 4 lights this week but it shan't cause me to rush out for a new battery. I'm sure I can get another year out of it.....hopes!

Indalo

 

[flecc]

For the first time ever, my battery has failed to produce all 5 lights on the press-and-hold test. Only 4 lights this week but it shan't cause me to rush out for a new battery. I'm sure I can get another year out of it.....hopes!

Indalo

It could recover to five lights with warmer weather. Also worth remembering that a full conditioning cycle will return the meter to accuracy, but it's not worth bothering with that while it's cold, best done in the Spring.

 

[Jimod]

OK, I've got the perfect solution to the problem of keeping batteries in use during
winter. Now, you're going to laugh at me but that's OK I'm a big boy and can take it. My wife bought me one of those indoor training things where you ride your bike on rollers. Now I can fully understand the irony of an E-bike on a set of training rollers but it gives me a bit of a work out and uses the battery as if I were riding on a flat level road.

Hopefully by the time the weather turns better, my batteries will be in good condition and so will I. Well I might be in better condition than I would be without the trainer.

BTW have any of you tried keeping your balance on these things? So far I've done loads of miles but never more than 1 mile without having to reach out and touch the garage wall to stop myself coming off.

OK you can all start the jokes now but it IS working.

 

[flecc]

I think that's brilliant Jim, reduced effort training! Get the video camera out, it could be a hit on YouTube.

Joking aside, you could be getting training benefit anyway. Many members have posted how having e-assistance has got them cycling and increased their fitness, so the same concept can work for trainers. Better some activity on an assisted trainer than not using it at all and using the armchair instead.

I can understand some types of e-bike making balance on a trainer more difficult though, there isn't the instinctive compensation for effort that using ones own body has.
.

 

[rog_london]

Any advice on storing SLA batteries during the lower use winter months?they are at present stored in the house at about 65f

The best storage temperature for SLAs is just above freezing. Provided they are in good condition and fully charged they can drop well below freezing but not for weeks at a time. Sulphuric acid at battery concentration doesn't start to freeze until well below the freezing point of water BUT if the battery remains below freezing for long periods water 'sublimes' in the air spaces - what happens is that the water vapour (which contains no acid) does freeze without going through the liquid state, and ice crystals can build up. It's the same thing that happens in your freezer when that pack of frozen turkey steaks has been in there for too long....

The ice crystals can themselves cause damage if allowed to build up. The problem becomes worse if the battery is not fully charged or in good condition as the acid will be at a lower concentration in the first place.

In most of the UK temperatures are never low enough for long enough for this to be a problem - just don't store your batteries in the freezer. The battery in my company van is now 11 years old and the vehicle gets left outdoors for weeks at a time unused - but it still starts at the first turn of the key even in mid winter.

If you wish to charge or use your SLAs let them warm up - as with all batteries (some more than others) the chemical reaction they depend on is very sluggish at low temperatures. However, storage close to freezing when not in use will prolong the life of the battery almost indefinitely.

Rog.