I want a rechargeable power bank that will supply USB, and a 12V car "cigarette lighter" accessory output. Power poles would be awesome but I can make adapters. It should have the option to charge from USB, 12V, or solar. Preferably with a good OLED display that tells you charge status, etc.
Every one of these I can find is sealed up and designed to be disposable. The thing is, the vast majority of these power banks use common 18650 lithium cells inside.
Does anyone make a power bank that allows you to easily access the insides and replace the cells? I am not opposed to soldering in new cells myself, and I don't mind if it's screwed together.
But most of these are assembled in such a way that you would damage or destroy the case trying to open them up to replace the batteries.
This will be for a specific emergency power use (backup for other devices, and for portable ham use) and if I am unable to periodically cycle the cells through some charge/discharge cycles, they will eventually develop high internal resistance and fail.
The trouble with lithium rechargeables is that you have to use them periodically, and that isn't practical when I have so many devices that use them. I have cameras, tablets, computers, radios, test equipment, gun optics, power tools, flashlights, video game consoles, headphones and earbuds, toys, and more, all of them powered by internal, non-user-serviceable lithium cells.
I want the backup device, (this power bank) to be user servicable.
I absolutely despise the trend towards disposable electronics with proprietary internal batteries.
Yes, recharging is cheaper than buying alkalines. But not for devices you only use a few times a year. And I have a ton of devices that only get used a few times a year.