Power Bank Below Feezing

The summit series has a temp sensor(s) on the battery cells. When it drops, part of the battery is discharged (a very small bit) to maintain higher battery temperatures – this allows it to maintain voltage so the battery can discharge energy to the device it’s charging.

With conventional portable chargers that don’t have this, the voltage drops so low in cold temps that it can’t discharge energy well – if at all.

I have a summit bank and have successfully charged my phone in temps below zero with no issues. When I use my regular nitecore batteries it takes about 5x the time to charge the phone at the same temps.

I was just charging my Samsung phone when it was 32F.  The phone said it was slow charging because it was too cold.  The powerbank didn’t complain, but it couldn’t communicate with me.  When I got home it wasn’t excessively discharged. I just figure I have to put both phone and powerbank in an inside pocket.

Which is what you said you don’t want to do : )

Snowshoed for 5 hours Sunday at -12C and my phone didn’t lose even 5% battery or any function while stored outside my pocket in a bum bag, but kept in my DIY reflectix phone cozy.  Took it out only sporadically to check tracking while bushwacking down some ravines.

That thing’s a game changer in winter for keeping the phone temp up and battery charged.

It wouldn’t work for long on a standard power bank though because the bank has no circuitry running to generate heat.

So if one keeps the phone in a cozy during the day, and as close to your body as you can tolerate, and then you toss them both in the foot of your sleeping bag to warm up and then charge the phone up again, would that do enough for you?

Or if you had a DIY ReFlectix pouch for BOTH of them – all the inefficiencies of discharging, charging, and battery self-care would synergistically warm the other unit and that heat would be retained longer.

That’s a ringing endorsement of the Nightcore Summit, and good reminders to take the usual basic precautions.