Why are there no A or B batteries?

Related questions

1. What are the disadvantages of lithium ion batteries?
2. What voltage is a 1.5 volt battery considered dead?
3. How long do coin batteries last?
4. What is the smallest battery?
5. What voltage is AC battery?
6. Are cr2016 and cr2025 batteries interchangeable?
7. Does a battery weigh more when fully charged?
8. Does mass change when body is charged?
9. Will AAA replace my battery?
10. What is the most powerful small battery?

Tags

1. #devices
2. #provide
3. #battery
4. #tubes
5. #vacuum
6. #specifically
7. #radios
8. #longer
9. #primarily
10. #voltage
11. #batteries
12. #plate
13. #sometimes
14. #commonly
15. #bonus
16. #because