D cell Ah ratings

[chris French]

Would have thought this was easy to find, but i've goggled and it's not straight away obvious.

Anyone know what the Ah ratings for typical Alakaline or Zinc carbon D cells is?

I've picked up an LED lantern to use for camping that takes D cells. I was wanting to check on the ratings of disposable D cells to compare them to NiMh to see if I think it's worth buying some for the amount of use it would get.

Cheap NiMH seem to be hardly anymore than AA in capacity, decent sized ones (5000 mAh - 10000 mAh) cna be pretty expensive

TIA

[David WE Roberts]

ISTR that the cheap ones are basically an 'AA' battery in a larger shell. This would tie in with the capacity.

No idea of the rating of disposables, though.

Cheers

Dave R

[Andrew Gabriel]

I think a real full-spec alkaline D cell is around 13000mAh. Trouble is that lots of the cheaper ones won't come even close. It will also depend on how quickly you drain the battery, and what you regard as the level at which it's no longer usable. Zinc carbon will be much less, but I don't have a figure.

About 18 months, I made a toy for a newphew which uses three alkaline D cells, partly as weights, as well as for powering it.

've not yet needed changing, even though it has been used a lot, and left on when they went away on holiday for several days.

Rechargable NiCds and NiMh have always lagged some way behind the higher-end non-rechargable technology. That's part of the price you pay for reusability.

Back in the days of NiCds, a proper high temp D cell was 4Ah. However, a large number of the D cells were actually C cells in a larger package (1.2 Ah IIRC). It seems that this practice continues with NiMH too, using even smaller real cells.

[Man at B&Q]

It depends how you use them.

Look at the datasheets on the Farnell website, or similar. They (the duracell ones at least) have graphs of service life against cell voltage and load.

if your LED lantern has a switch mode supply to drive the LEDs then it will probably carry on working to quite a low cell voltage, allowing you to get the most out of the cells.

MBQ

MBQ

[Simon C.]

From memory, Duracell D cells claim to be 15,000 mAh.

Last week my local Lidl had D cell NiMH for £2.49 for 2, and they were 'proper' D cell, ie not AA in a case. I think they were 5000 mAh. Far cheaper than others I've seen.

[Bruce]

My local Lidl still has some in stock, or did on Sunday. They are among the higher capacity NiMH D cells available, and excellent value for money.

[NT]

a start

NT

[robgraham]

I do like your 'toy', Andrew - an impressive bit of engineering in a very short time, Well done. Rob

[dennis]

I think they were C cells in a D case, they had the same mAh.

[Simon C.]

Ah, in which case you're probably correct. I just went by the weight and they seemed about right for a D. Didn't know they did C disguised as a D trick.

[John Rumm]

Some eBay sellers are touting 8 and 10 Ah D cells now.

I have quite a number of AA Vapex branded 3Ah cells that have done very well. I Note you can get 10Ah D cells from them also:

[John Rumm]

Hmm, looks like that could do with some updating...

[Man at B&Q]

:

they've been available for a while.

9Ah for =A37.04+VAT 2 for =A316.95+VAT

[Bruce]

from Lidl by saying that they were "among the higher capacity NiMH D cells available on the High Street".

[John Rumm]

> Thanks John. Perhaps I should have qualified my praise for the ones

Well to be fair, 5Ah, used to the top end for a NiCd D cell for many years. NiMh has pushed past that more recently. The lower capacity ones are still better in terms of purchase price per Ah though.

[chris French]

Thanks for the comments everyone. Found the info I was looking for.

Given the price for higher capacity NiMH D cells, and given it's useage pattern - where it sits in a crate in the trailer waiting to go camping (for a few days or a few weeks), gets used for a weekend or week and then goes back to wait around for a while. So I'd just have another thing to think about to make sure the cells were charged up at the right time (cells I wouldn't use for anything esle, unlike AA's which we have lots of), and would need a different charger etc to take with us (we have a small AA/AAA only charger for camping/travelling).

I think I'm probably going to stick with Alkaline cells for now. I might experiment with AA's in D cells adapters to see what run time I get.

[PeterC]

In that case (sorry) and given the pattern of use, the Eneloop or similar might be best: lower capacity but at least it's there when required.

[NT]

:

Another possible might be to make the torch chargeable from the cig lighter socket. With so little use though its hardly worth it.

BTW I found gas lighting far more reliable than any battery solution for occasional use lighting.

NT

[chris French]

Like I said, I'll probably try them out, but it depends on the run time as to wether I think it's worth it.

[chris French]

In message , NT writes

No I don't think it is. I found also with a previous rechargeable lantern that I'd tend to forget to recharge it until it was dark.....

We have gas lanterns as well, ands we much prefer the quality of the light from them for camping. But they have their own issues.

I don't really like them around in the tent (especially our smaller ones) with the kids around (yes they know to be careful around them, but they aren't always and we can do without the hassle). You can't really hang them from the tent roof for area lighting because of the heat. Gas in disposable cylinders is pretty expensive. They are prone to breakages of the fragile mantles or of the glass globes.

A petrol lantern would in many ways be a sensible choice, as we use a petrol stove. But generally use unleaded petrol in it. Don't feel so happy about the additives in unleaded petrol being released into the air when used inside a closed tent (I accept this may be unfounded, but there you are).

The stove doesn't really concern me so much as it is normally used outside, or under a sheltered area, not in the tent.