Storing rechargeable light over the summer

[Bristol Dave]

Just a quick question for those in the know: I have 2 rechargeable lights that I haven't used for a week and will be taking off of the bike at the end of the month. Is it best to store rechargeable lights fully charged or completely drained or does it not really matter? There was no advice in the one leaflet I had with the lights.

Loving the spring weather - sunny but cool enough to keep the perspiration low

BD

 

[BentMikey]

I dunno mate, but I think it'll depend on what type of batteries they use. I don't have this problem as I end up using mine all year round. Partly because I run them during the day, and partly because 3 commutes a week will be home in the dark even at midsommer.

 

[Brommie77]

I always reckon to store them fully charged, then give them a quick cycle when it starts getting dark again (eg leave it on one day to discharge any remaining charge), and fully charge them up again. Modern batteries dont have the 'memory' that that the older ones had, but I like to make sure that when I start the light is fully charged, and I'm not always sure that the charger sensor is accurate enough if you only need a small top-up charge.

 

[BSRU]

If there Li-ion then apparently best to store at 40% charge, how you know it's 40% god knows.

Li-ion Battery Care

 

[leemo]

If there Li-ion then apparently best to store at 40% charge, how you know it's 40% god knows.

Li-ion Battery Care

My naive brain draws an analogy with a spring, another store of energy. If you stored a spring fully streched or fully compressed its neutral state might become more stretched/compressed after a while and therefore it would not be as springy. Whereas if you store it in a more neutral state it would keep more springiness. I think; I could be talking bollox but it sounds feasible.

 

[gbb]

My naive brain draws an analogy with a spring, another store of energy. If you stored a spring fully streched or fully compressed its neutral state might become more stretched/compressed after a while and therefore it would not be as springy. Whereas if you store it in a more neutral state it would keep more springiness. I think; I could be talking bollox but it sounds feasible.

It may be bollox (it may not be) , but it sounds good

 

[gbb]

SLA batteries of course need a regular top up if being stored for the summer. Let em go flat, you virtually kill them, and they do discharge rather quickly, even from a full charge.
Does anyone still use them ?

 

[Tynan]

every day for me, they're certainly bright enough to make a difference

 

[Bristol Dave]

If there Li-ion then apparently best to store at 40% charge, how you know it's 40% god knows.

Li-ion Battery Care

Thanks for the link. I have a Li-ion and a Ni-Mh battery pack. As to the 40% charge I'll charge it and run it for a couple of hours (4 hours 'life' at full beam according to the leaflet) which should be close enough.

BD

 

[PatrickPending]

answers may be found here:-

http://batteryuniversity.com/

 

[Wobblers]

As has been said, lithium-ion batteries are best stored at 40% charge (half-charged is fine) in a cool place. Which, in my case, means guessing how much runtime I've used! Don't leave them flat, they'll probably just die on you, so check the charge every couple of months.

Nickel metal hydride batteries are a bit different. It seems they prefer to be stored charged. It also helps if you can cycle - charge and then discharge them - every couple of months. This "works" the chemicals inside so that they don't recrystallise into a less active form.