present timer, and if I add another Tesoro or two, they will also be using 9-Volt batteries.
I never use rechargeable batteries for a few reasons. Cost, annoyance, down-time for charging, frequently they are off-sized in length and/or width to properly fit a Tesoro, and the main reason is that a decent quality alkaline battery lasts a long, long time. I use ONLY alkaline batteries.
I usually use Duracell, and if they are not available then it is Energizer, and I still keep an eye out for off-brands of alkaline batteries, and most often I can find them on a sale and they last just about as long as the Duracell brand 9-Volt does.
Monte