Ever since purchasing rechargeable batteries, I only have to replace these batteries every 5 years. Never had a problem with them and they last longer then regular batteries. I've used them with remote controls and other electronic devices. Take note not to mix this up with regular batteries as some labels may be confusing from those that are chargeable from those that are now. Lasts long and saves money.
These batteries are about 3 times more expensive than your traditional Alkaline batteries, but you can charge them 1,000 times. Alkaline batteries last quite a long time and are ready from the box, but rechargeable NiMh batteries last 2/3 the same and only take 8 hours to charge. Really, would you rather play $6,000 for convenient, but environmentally damaging battery or $24 for a single set of batteries you will use for a few years. They're not perfect, but I still prefer responsibility.
A:AnswerYes and Yes to both your questions. PS -- I have read some reviews that 1.2V may not work as well for devices designed for 1.5V, but I have never had a problem -- 1.2V works perfectly on all my stuff. I also think the quality of rechargeable batteries has increased a lot in the years. I have a few old Radio Shack batteries that died early.
A:AnswerThese are claimed to be 850mAh but I have not found any definitive test info to verify this. There is at least one data sheet online that shows them to be only 700mAh. As most of these rechargeable batteries, the voltage is usually 1.2 volts. Sorry I can't be more precise.