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Quick electrical one
Ninehigh - 30/4/12 at 03:18 PM

I have a small speaker powered by 3 AAA batteries, now if I was to solder each terminal up to a D cell battery it would last longer right? My thinking is that the larger cell holds more amp hours (or kilowatt hours etc) than a AAA.

Am I right?

MikeFellows - 30/4/12 at 03:25 PM

but surely the 3 AAA give 4.5v to the speaker where as one D would only give 1.5v?

ReMan - 30/4/12 at 03:34 PM

Yes it will last for ever
Edited to add, I was wrong, I was remembering D as this one
http://www.conrad-uk.com/ce/en/product/650802/High-Energy-45V-flat-battery

D is indeed 1.5 and you need 3, then they will last forever

[Edited on 30/4/12 by ReMan]

owelly - 30/4/12 at 03:35 PM

AA, AAA C and D are all 1.5volt

scudderfish - 30/4/12 at 03:38 PM

Short answer, yes.

http://en.wikipedia.org/wiki/D_battery#Dimensions_and_capacity

vs.

http://en.wikipedia.org/wiki/AAA_battery

Ninehigh - 30/4/12 at 03:39 PM

Sorry yes it would be three D batteries too in order to keep the same voltage

MikeFellows - 30/4/12 at 03:40 PM

both those articles list the batteries at 1.5v

if the AAA batteries are inline they will be running 4.5v (if parallel then 1.5v but ive never seen anything run parallel)

a single D battery will not be enough to power the speaker


eta:

oh you meant 3 - yes this is fine

[Edited on 30/4/12 by MikeFellows]

Ninehigh - 30/4/12 at 03:50 PM

Thanks guys, now to go find some d-cell holders

cliftyhanger - 30/4/12 at 04:21 PM

However.....check the capacity of the batteries. Many of the small batteries, especially rechargables, have equal or better capacity to the larger, less used types.
However, AAA are small and therefore tend to be low, but have a peek at AA size, you may be surprised!

ReMan - 30/4/12 at 04:26 PM

quote:
Originally posted by Ninehigh
Thanks guys, now to go find some d-cell holders

either that or a.n. otehr alternative.
I presume a mains adaptor is not possible?

MikeRJ - 30/4/12 at 05:47 PM

quote:
Originally posted by cliftyhanger
However.....check the capacity of the batteries. Many of the small batteries, especially rechargables, have equal or better capacity to the larger, less used types.
However, AAA are small and therefore tend to be low, but have a peek at AA size, you may be surprised!


Plenty of rechargeable C and D cells are simply AA cells with a plastic sleeve around them!

You'd probably be surprised at the capacity of good Alkaline D cells; at reasonably low current drains (<500mA) they can have well over 15 Ah.

Ninehigh - 30/4/12 at 07:53 PM

quote:
Originally posted by ReMan
quote:
Originally posted by Ninehigh
Thanks guys, now to go find some d-cell holders

either that or a.n. otehr alternative.
I presume a mains adaptor is not possible?


Not really, it's a portable speaker.. I use it a lot in the car and such plugged into my phone (the car radio is a pita with the plugs)
I'm just thinking it would be cheaper overall to use larger batteries, as there's room in the housing for it.

I'll have a look for the mah numbers

Peteff - 1/5/12 at 08:56 AM

Get a car accessory phone charger to plug into the lighter, the USB type will do it. They run about 5v which should work.

Ninehigh - 4/7/12 at 08:11 PM

Another one!

I've got the holders, but the spring from one negative terminal is connected by the positive terminal from the other battery (so both batteries are in series)

Will I have to break that connection? It looks like the original set up is parallel, so I'm not sure if I could get away with running a 3 sets of wires if one of them is also going to be connected in series