# How come you never see any B batteries?

**URL:** <https://boards.straightdope.com/t/how-come-you-never-see-any-b-batteries/1163>\
**Category:** Cecil's Columns/Staff Reports\
**Created:** [April 8, 2000, 1:41am UTC](https://boards.straightdope.com/t/how-come-you-never-see-any-b-batteries/1163 "2000-04-08T01:41:00Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![ralphredan](https://avatars.discourse-cdn.com/v4/letter/r/f4b2a3/32.png) [@ralphredan](https://boards.straightdope.com/u/ralphredan)\
**Post date:** [April 8, 2000, 1:41am UTC](https://boards.straightdope.com/t/how-come-you-never-see-any-b-batteries/1163/1 "2000-04-08T01:41:00Z")

</div>

How come you never see any B batteries?[http://www.straightdope.com/classics/a4\_005b.html](http://www.straightdope.com/classics/a4_005b.html)

The letters A, B, C, and D were used to describe the batteries in old RCA radio sets, which had 4 independent circuits. One for the tuner, one for the speaker, etc.

They were named in order of size, but A and B were too close to C to be popular and a smaller size was needed, hence AA, then AAA.

---

<div class="post-metadata">

**Author:** ![egkelly](https://avatars.discourse-cdn.com/v4/letter/e/db5fbb/32.png) [@egkelly](https://boards.straightdope.com/u/egkelly)\
**Post date:** [April 8, 2000, 5:26am UTC](https://boards.straightdope.com/t/how-come-you-never-see-any-b-batteries/1163/2 "2000-04-08T05:26:00Z")

</div>

Wrong! B-batteries were high-voltage batteries (100 - 500 volts), used in the days of portable TUBE radios-yes Virginia, there were tubes before transistors. I can remember them-they were large and very expensive-if you wanted to play your radio at the beach, it would cost you quite a bit! (they were not rechargable).

---

<div class="post-metadata">

**Author:** ![Morrand](https://avatars.discourse-cdn.com/v4/letter/m/a3d4f5/32.png) [@Morrand](https://boards.straightdope.com/u/Morrand)\
**Post date:** [April 8, 2000, 11:17pm UTC](https://boards.straightdope.com/t/how-come-you-never-see-any-b-batteries/1163/3 "2000-04-08T23:17:00Z")

</div>

I dunno, I buy into Cecil’s explanation more than the separate supplies one. If I remember correctly, the supplies broke down like this:

A - filament supply, about 1-12 volts maybe

B - plate supply, abt. 40-200 volts

C - grid bias supply. Negative and small valued, maybe -1 to -10 volts?

D - never seen that, and since filament, plate and grid supplies pretty much cover all the bases, I don’t know what it would power.

Somehow, I don’t think they would label the B-supply battery a “B battery” on the shelf, since not all receivers would use the same B supply voltage. I built a one-tube regenerative radio once, and its “B battery” was simply labelled a 45 volt battery (the A supply was a C cell, oddly enough).

---

<div class="post-metadata">

**Author:** ![justwannano](https://avatars.discourse-cdn.com/v4/letter/j/7ab992/32.png) [@justwannano](https://boards.straightdope.com/u/justwannano)\
**Post date:** [April 9, 2000, 3:23am UTC](https://boards.straightdope.com/t/how-come-you-never-see-any-b-batteries/1163/4 "2000-04-09T03:23:00Z")

</div>

I thought B batteries were those that we used in jr high science class. A little larger than a large water glass. 1 1/2 volts dry cell brown paper cover .Mine was the only dead one.