Passthrough charging of power banks

[SawMaster]

Haven't heard of Mi (powerbanks aren't my specialty) but Anker, Aukey, and real Xiomi (watch for fakes there) are good choices. LiIon cells made by Sony, Panasonic, Samsung, and LG are the ones to look for but without opening it up (or buying one of the recommended brands) you can't know what's inside and many sellers will claim anything to get your money.

There are some other LiIon cells which are good but that does not apply to all their brand-name cells, only specific ones, so not knowing that I can't recommend any other powerbank brands but I do trust Dashmellow's recommendations completely- he knows his stuff with LiIon's too.

Phil

 

[Dashmellow]

Normally no. Hot interior temps such as a car sees parked in the summer will reduce the lifespan of LiIon batteries but only in extreme cases would I be concerned about safety. The quality of the cells and charger are the critical parts of LiIon safety (though not the only parts) and the best cells generally fail less catastrophically than 'venting with flame' like you see on the youtube vids. But there's always going to be a tiny percentage of catastrophic LiIon failures due to unseen manufacturing issues and also failures in safe use and charging. Just keep the powerbank out of direct sunlight and you should be OK anywhere save for a desert environment.

With good equipment and proper care, you're far more likely to be struck by lightning than to experience thermal runaway or venting with flames using LiIon. With low quality stuff anywhere in the mix or improper care the risks increase greatly.

Phil

I basically agree with your comments here but you are speaking in terms of using "proper care". Keep in mind that this thread up until now has been about the desire to keep a powerbank constantly charging (and discharging) in a vehicle 24/7 in a tropical climate where it would be subjected to ongoing heat, shock and vibration. This is hardly "proper care". There is a huge amount of energy stored in a good sized powerbank and abusing one in this manner is pushing your luck regardless of the quality of the cells, especially as the cells age. Since power banks were never really intended for the way we use them with dash cams I think an abundance of caution is a wise approach.

 

[SawMaster]

Since power banks were never really intended for way we use them with dash cams I think an abundance of caution is a wise approach.

Agreed completely. LiIons are like racehorses- very specific needs and very little room for deviation from them. When you push the envelope with these the resulting failure can be extremely bad. With LiIon's you MUST respect their limits.

Phil

 

[DavidUK]

I found a while ago thanks to @Dashmellow and the battery university that LiFePO4 internals appear to be the safest.

There's a few here: http://www.colorfly.eu/DEBOCH T12000/index.html

So far I've not taken the plunge for parking up, as my car's 12v sockets remain live for 30 minutes which is often enough for "dangerous" situations where I park.