I ordered (and should receive today) one of these highly regarded ENB triple 18650 "power bank" / "mobile chargers" from FastTech. My intention was to keep this in my vehicle's glovebox for emergency use (it provides me an emergency flashlight, an emergency 18650 charger, as well as an emergency "power bank" / "mobile charger"). The three cells are in parallel of course. In my region outside temps range from about -15F to 105F (-26C to 41C for you weird people that use Celsius ). My car is kept inside an unheated garage overnight probably 98% of the time.
I have a few questions though. I'm mainly concerned about safety, not so much about battery capacity.
1) Is it safe to use used Laptop battery pack pulls in this device in the extreme weather conditions? If not, are three new matched cells ok? What about IMR or INR instead of ICR chemistries? (I don't have a hobby charger to check laptop pulls capacities, but I have a good idea of their condition based on charging them, monitoring them after charge for weeks and weeks, and now putting a couple to use.)
2) Am I only reducing the cells capacity / life using them in these conditions? Or are there other concerns?
3) Now a question on the use of my EDC 18650 light in these weather conditions: Just a couple days ago I was working outside in 18F (-8C) - on the top of a ridge where windchills were probably closer to -10F (-23C) - with my EDC (Convoy S2 with unprotected 18650 laptop pack pull) in my pants pocket barely protected at all from the cold. Should I be concerned about having my EDC exposed to such cold weather?
I think the heat will kill it fast, i bought a 2AA light specifically to leave in the car because i trust eneloop to last a lot longer then li ion
I don’t know a lot about cold, though in one thread someone mentioned that li ion will work at –20 where NiMH won’t, but i have no additional data to provide
li-ions usually work fine down to very cold temps, but hate being charged when cold. Being very hot shortens their life too. That said, we’re talking relative here (say 1000 charge cycles to 100 cycles) and they’re not going to be heavily used, so I think that they should be fine. Most li-ions maintain their charge well in my experience, so just check the bank every once in a while.
THis is something I’ve been meaning to do for ages, thanks for the reminder!
"Cold temperature increases the internal resistance and diminishes the capacity. Batteries that would provide 100 percent capacity at 27°C (80°F) will typically deliver only 50 percent at –18°C (0°F). The capacity decrease is linear with temperature. The capacity decrease is momentary and the level of decline depends on the battery chemistry. Li-ion also performs better at high temperatures than at low ones. Heat lowers the internal resistance but this stresses the battery."
I don't really know what to think. Guess I'm just going to try it with laptop pulls.
I am currently testing my new ENB charger/power bank and so far I really like it. Tested recharging 3 cells and then using the power bank to recharge my iPhone. The built-in flashlight feature isn't too bad either. I also like that it has a slow beacon mode, handy for roadside warnings. Picked up this 120v AC micro-USB charger and this DC 12v micro USB charger, both rated at 2A output (I wasn't sure how much Amperage I needed and felt 2A was safe and would suit future usage on other devices). Both chargers were well reviewed and seemed the best choice for the lowest price.
I’m keeping a bank in a day bag that sometimes stays in the car, but it gets periodic attention and often makes it indoors - so far it’s doing OK. I’m looking for another since I think it drains too fast.
I’m more concerned about the cells being dead when I want to use them than I am their life (mine were also free pulls). I keep an 18650 light in each car with primaries so that I should have something that works and has backups with charging capability.
Note - make sure the cells you select are LSD - out of ~150 some of mine seem to drain more quickly at rest than others.
). My car is kept inside an unheated garage overnight probably 98% of the time.