Current supply for 1.5v batteries?

[gooseEL34]

I need to build a mobile 9v supply.  Anyone have the current supply ratings for AA AAA and C and D batteries?
Tim

[gooseEL34]

I am building a mobile guitar rig that uses a Roland cube amp.  This will be used to power a Boss GT3 multi effects unit which has an AC to DC wall wart that supplies the 9v source

[dannyf]

I assume that all aaa/aa/c/d batteries are the same, regardless of make and chemistry,...?

[gooseEL34]

Ooh.  Good point.  I was making an assumption.  Guess it is a battery by battery issue.

[grumpydoc]

Anyone have the current supply ratings for AA AAA and C and D batteries?

Not off the top of my head but I suspect that Google can find a few datasheets for you.

Don't forget that capacity depends on multiple factors including temperature and discharge rate and, of course, chemistry.

[mariush]

See http://www.batteryshowdown.com  - they tested a bunch of batteries at 200mA and 1A :

200mA : results and chart with all batteries: http://www.batteryshowdown.com/results-lo.html



1A : results and chart with all batteries : http://www.batteryshowdown.com/results-hi.html



So it depends on how much current the battery needs to provide and the battery type and the quality of the battery.

I don't know the capacity of C or D type batteries but I suspect it would be around 3-4000mAh but then you're probably better off with some lithium 18650 or regular flat batteries.

--
Now I don't get exactly what has to be powered from 9v, because you talk something about an amp and other things.

Measure the current consumption of the device that needs 9 amps then go from there. If that thing only needs 10-100mA, you could do something like I did for my multimeter, a dc-dc boost regulator:  https://www.youtube.com/user/HelpediaVideos 

Basically, the multimeter I have takes a 9v battery but it shows low voltage indicator at around 5.5v so I used a LT1307 to boost 1-3v to about 5.7v (just above the low voltage battery). The boost regulator can output 5v from 1v, from about 1.15-1.2v it can probably do 7-8v, well within a 9v battery range.  So you could replace the 9v adapter with as little as one 1.5v alkaline battery (but it would be more efficient to use 2 or 3 batteries) and this boost dc-dc converter, as long as the device doesn't draw more than 100mA (the maximum limit this LT1307 can do)

If you need more current, you'd be better off with putting 8 batteries in series and just running it directly, or maybe through a switching regulator in SEPIC configuration.

[Psi]

Modern D cells can be up to 18000mAh but 99% of the D's you see for sale are actually AA or C inside a D container so are more like 2000-4000mAh

They fake them like that because it's cheaper and modern AA and C cells have the power handling capability of the original D cells many years ago.
Products are no longer made that need D cells so all the products that people buy D's for are really old and can work fine with modern AA's.

I wouldn't recommend making a new product that uses C or D cells, they will start to get hard to find pretty soon.

If your product needs to have batteries available for the user to purchase, use AA's.
If it needs high current add a sticker that says "use rechargeable only" or have a battery holder that can be wired to have multiple banks of AAs in parallel.

If you still need more current use those larger lithium cells you find in cordless drills, i forget their name.
But then the device needs a built in charger.

I wouldn't recommend those cells that look like AA but are 3.8V lithiums, it's too easy for people to install a normal AA and wonder why it doesn't work.

You can also get single use 1.5V lithium AA's which work well for high currents but are expensive.

[IanB]

D cells can be up to 18000mAh but 99% of the D's you see for sale are actually AA or C inside a D container so are more like 2000-4000mAh

Mainly because it's cheaper and modern AA cells have all the capacity and power handling of the original D cells many years ago.
Since products are no longer made that need D cells all the products that people buy D for are really old and can work fine with modern AA's.

I wouldn't recommend making a product that uses C or D cells, they will start to get hard to find pretty soon.

If we are talking NiMH rechargeable cells then it is true that C and D cells often have a compact sub-C cell inside them. I think real NiMH D's can be up to 12000 mAh or so. A genuine (not marketing sham) 18000 mAh is more than I have seen in a D cell.

For alkaline cells, the C and D sizes are fully genuine. No way can an AA alkaline handle the load and run time that a D cell can.