Battery charging
- Thread starter Fulk
- Start date
You would indeed want a spare fully charged, so ideally charge it before going and allow it to drop off slightly between trips. I don't think it loses a lot of life leaving it fully charged, and the convenience outweighs the cost of replacing it a bit sooner. It's when the batteries are in something like an electric car that you really need to pay attention to battery life.
Cantclimbtom
Well-known member
I'm intrigued, wormster, as to how you manage your 18650s; your post suggests, perhaps, that you have a number of these (for group use?). How do you maintain them at 30%? Obviously you know in advance when they ae likely to be needed, and charge them up. But after use, do you somehow run them down to this specific level?
wormster
Active member
Ah we have 'fasands of the little buggers at work, they get shipped in bulk from the manufacturer, at 30% S.O.C. we then put them through a rigorous screening process, that happens over an 8 week period, don't arsk how the software works (it's beyond my pay grade) but that does all mean nasty charge and discharge cycles and eventually returns them to resting voltage, when the cells are not being used they're stored under ideal conditions of 20 Celsius, and 5% relative humidity.
I can't say anymore due to NDA agreements in my contract of employment
I can't say anymore due to NDA agreements in my contract of employment
Very interesting. I'll continue my maintenace schedule of not charging them after previous trips until needed. Thank you
alanw
Well-known member
My charger cuts out at 4.2V. I have a single cell pack (Panasonic) with board (ie not a button top) that was at 4.08V after over a year and it seemed to be holding the appropiate charge when I tested it yesterday. I find this to be the case for all our spares. Just in case this was a bit spurious for some reason I previously ran various packs through discharge cycles and saw nothing you wouldn't expect based on the initial voltage.
I keep the batteries in the garage and I see very little voltage decline over time (I measure them before use). I normally charge the packs just before we go caving apart from the spares which are left as above. I am still using two Scurion packs I got with my lamp ten years ago and see little difference to when new. I think if you buy something like a Panasonic buttontop from a supplier in the UK you are unlikely to have an issue. You need to make sure there is plenty of headroom on the current cutout if using it in a fenix type lamp - at least 10A would you believe. On a purpose-built caving lamp this should not be an issue as they have better current control. If it trips out it may need connecting to a charger to reset which could be chastening underground.
I keep the batteries in the garage and I see very little voltage decline over time (I measure them before use). I normally charge the packs just before we go caving apart from the spares which are left as above. I am still using two Scurion packs I got with my lamp ten years ago and see little difference to when new. I think if you buy something like a Panasonic buttontop from a supplier in the UK you are unlikely to have an issue. You need to make sure there is plenty of headroom on the current cutout if using it in a fenix type lamp - at least 10A would you believe. On a purpose-built caving lamp this should not be an issue as they have better current control. If it trips out it may need connecting to a charger to reset which could be chastening underground.