Battery charging warning

royfellows

royfellows

Well-known member
Just a heads up with the weather
Its dangerous to charge Li Ion batteries in sub zero temperatures.

Laptops, mobiles etc are usually kept in the house. Caving gear often in garden sheds. If that is where you keep your lamps dont charge them there, its dangerous.
I would not recommend keeping them there, or leaving them in the car.
 
Simon Beck

Simon Beck

Member
Thanks also!

Confirms my suspicion. Had charging issues with one of my 18650 (FX) after a period of subzero storage in car. 
 
royfellows

royfellows

Well-known member
Electronics can and do pack up as well in sub zero, you will all have experienced this I expect. Dont forget also that Li Ion cells are under electronic control to prevent over charge, over discharge, and short circuit.

 
F

Fulk

Well-known member
Thanks Roy for the warning; we walked back from County Pot on Sunday, then put our stuff in the back of the car, so I guess our 18650s were very cold by the time we got home. I put them straight on charge, but they seem to have survived; in future, I'll make sure the batteries travel in the front of the car!
 
M

MJenkinson

Member
So cold is OK but not sub zero? Scurion Manual says to store batteries in a refrigerator or cellar.  Fairly sure my garage is currently below freezing so I best move the battery into the house.
 
royfellows

royfellows

Well-known member
MJenkinson said:
So cold is OK but not sub zero? Scurion Manual says to store batteries in a refrigerator or cellar.  Fairly sure my garage is currently below freezing so I best move the battery into the house.
Click to expand...

Note the the word "charge"

Some stuff, all one ever has to do is a little research, never mind.

https://electronics.stackexchange.com/questions/263036/why-charging-li-ion-batteries-in-cold-temperatures-would-harm-them

Wikipedia, about half way down "Extreme temperatures"

https://en.wikipedia.org/wiki/Lithium-ion_battery

In effect, charging will fail at sub zero, if it doesn't you may want to consider putting a fire extinguisher close by.

 
royfellows

royfellows

Well-known member
aricooperdavis said:
Thanks Roy - I bought one of those "dodgy" ebay bike lights (and, so far, it's really good), but don't really know anything about Li-Ion batteries. I should probably do some research!
Click to expand...

If you remove the handlebar mount and fit a home made bracket, seal it with silicone. Other point is the silicone grommet that covers the switch, it may fix in better with some kind of seal, I dont know. Objective is to increases its resistance to water ingress.
If you buy a battery case with matching plug rather than the Chinese battery pack with junkfire cells, you can use you own choice quality cells.
So you end up with a half decent lamp for a few quid. But never as good as one designed for the job.
 
manrabbit

manrabbit

Member
How do car companies such as Tesla overcome this issue, is that a different Lithium chemistry to the 18650 cells that loads of us use. I think some of the Tesla batteries used to be made by Panasonic and seem to remember these also being 18650 cells. I suppose an intelligent charger could start of by warming the bank of cells before charging them. 
 
aricooperdavis

aricooperdavis

Moderator
I'm actually using mine as a bike light so water ingress isn't too big a worry for me, although I would rather charge with my own charger as I'm not sure I trust the built in charging circuit, so I'll take your advice and seal it up - Thanks! Any recommendations for good chargers and reputable batteries?
 
alastairgott

alastairgott

Well-known member
aricooperdavis said:
Any recommendations for good chargers and reputable batteries?
Click to expand...

I've seen a lurker use one of these (I've seen him lurking on his phone!). I think his has been used with a petzl duo upgrade. no idea how that works? but a nifty idea.

http://ledcaplamps.com/batteries.htm

Perhaps you could do the same? (sorry for the Fellow's plug, but he's the only one I know of doing reasonable aftermarket battery packs).
 
paul

paul

Moderator
manrabbit said:
How do car companies such as Tesla overcome this issue, is that a different Lithium chemistry to the 18650 cells that loads of us use. I think some of the Tesla batteries used to be made by Panasonic and seem to remember these also being 18650 cells. I suppose an intelligent charger could start of by warming the bank of cells before charging them. 
Click to expand...

Apparemtly:
When the battery pack is below freezing the car will not permit charging, as this will damage the cells.
Click to expand...


from https://teslamotorsclub.com/tmc/threads/cold-weather-driving.64591/
 
royfellows

royfellows

Well-known member
This is just opinion but I would think that electric cars have a battery compartment with a controlled climate. Also to answer other questions Sanyo and Panasonic are now the same company and work in partnership with Tesla. Tesla are producing battery cells, the 2170 which is 21mm X 70 mm and has a claimed 6250 mAh at nominal 3.7V

A lot of watt hours in a single cell, frightening, but also the future.
Reading tealeaves Tesla home or neighborhood powerbanks will become commonplace, kept topped up by solar and renewables. This carries quite a few implications, some political. A fall in demand for fossil fuels and a decline in dependency on Arab oil states.

Down to lamps, I am now offering power packs utilizing 2070 4250 mAh cells with high discharge rate. 3 of these in a helmet mount power pack powers my new X12 up to over 7000 lumens.

Its exciting stuff
 
Vulcan

Vulcan

Member
alastairgott said:
aricooperdavis said:
Any recommendations for good chargers and reputable batteries?
Click to expand...

I've seen a lurker use one of these (I've seen him lurking on his phone!). I think his has been used with a petzl duo upgrade. no idea how that works? but a nifty idea.

http://ledcaplamps.com/batteries.htm

Perhaps you could do the same? (sorry for the Fellow's plug, but he's the only one I know of doing reasonable aftermarket battery packs).
Click to expand...

I have a petzl duo (with an custom duo insert in) that I have upgraded to use li-ion batteries. I simply removed the old battery box and soldered an XT60 plug on to the cable to enable me to use the above battery. I have only used it twice underground, but it I liked it and no issues where found.

I had looked at other options including making\buying an battery box or modifying  the duos box but that was the easiest and cheapest option.
 
royfellows

royfellows

Well-known member
No, they were  low voltage, 4.2V off charge. I still make these for existing customers although no longer manufacture low voltage lamps.
 
Vulcan

Vulcan

Member
royfellows said:
No, they were  low voltage, 4.2V off charge. I still make these for existing customers although no longer manufacture low voltage lamps.
Click to expand...

What he said.

I use a custom duo V5 on which the battery meter can even be programmed for use with 4.2 V battery so it reads the correct amount of charge left.
 
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