Currently using 10 AA li-on rechargeables. Thinking of bumping it to 12 AA to compensate for voltage drop in cold weather.
You could use some lithium AA batteries with a bms that hold a steady 1.5v all they way to just before low voltage cutoff like the Tenavolt batteries. I use these in my locks to give me longer runtimes. They are pricey but at least they're rechargable.
Could also run series parallel for longer runtime as long as you know what you're doing assuming you made your own battery box.
Could you post a link to the chime? There's a lot of different ways to go about this.
Regular li-ion rechargeables actually have nominal voltage of 1.2 and 12 of those would actually give you 14.4v.
LiFePo4 batteries do better in cold weather and have a nominal voltage of 3.2 so 4 of those would give you 12.8 volts. Plus side is you can get them in a bunch of different sizes.
Original thread here:
My mailbox is located about 300 ft from the receiver.
I'm heavily invested in 1.2v li-on Eneloops and use them (if I can't convert it to USB, which is my preference). The mod works pretty well until the temperatures get around freezing. I should probably add a remotely located 12vdc solar panel after this .