Cells in Batteries

biffvernon · Post by **biffvernon** » 28 Dec 2011, 11:18

Lots of AA cells are hidden inside larger batteries. This is American but does the same apply here?

http://www.youtube.com/watch?v=cV6kxQYGVs0&sns=fb

emordnilap · Post by **emordnilap** » 28 Dec 2011, 11:25

It does happen over here, though I don't know how much. I've come across this. Edit: meaning multiple (usually four) cells - but never as many as shown in the video.

Also, some small 'rechargeable' appliances that come with a wall adaptor to charge them up use an internal 'pack' of AAs or Ds.

Funny, in the video it shows the same camera I have, which does not take AA batteries.

Post by **adam2** » 28 Dec 2011, 11:41

This is generally accepted to be an urban myth.
Someone, somwhere, may have manufactured 6 volt lantern batteries containing numerous AA cells but this is not the norm.

Cheap 6 volt lantern batteries contain 4 cells each D size and an expanded polystyrene spacer.
The better makes contain 4 cells each F size.

I have disected numerous 6 volt lantern batteries and have NEVER found one to contain AA cells.

Post by **adam2** » 28 Dec 2011, 11:47

This video shows the inside of a typical 6 volt lantern battery.
Contains 4 F cells
http://www.youtube.com/watch?feature=en ... 4YDGWd8vvo

biffvernon · Post by **biffvernon** » 28 Dec 2011, 12:09

Thanks Adam, that's pretty convincing.

biffvernon · Post by **biffvernon** » 28 Dec 2011, 12:32

I got that video from a facebook friend. I replied with your video, Adam, and he said

in fact the 17 I have so far dissected have yielded 272 AA cells and they are still spewing out from the cornucopia Lantern Batteries I have bought from the post office next door. They are old models and, as the shop never sells anything other than emergency sticking plasters due to peoples' preferences for the 12 mile round trip to ASDA's, the very last ones ever made in western civilisation.

Maybe it all depends. The trick is to know what's inside before wrecking it.

JavaScriptDonkey · Post by **JavaScriptDonkey** » 28 Dec 2011, 13:42

24 Duracell AAs in Sainsburys are £14.
I'm pretty sure I saw 18 packs in B&Q for £8.

Why bother even trying to liberate el cheapo cells from old lantern packs at all?

JohnB · Post by **JohnB** » 28 Dec 2011, 16:48

I think it's more useful to know how to replace odd sized and built-in batteries with something easily available!

Tarrel · Post by **Tarrel** » 28 Dec 2011, 20:08

JavaScriptDonkey wrote:24 Duracell AAs in Sainsburys are £14.
I'm pretty sure I saw 18 packs in B&Q for £8.

Why bother even trying to liberate el cheapo cells from old lantern packs at all?

18 packs in B&Q for £6.98 this aft.

Post by **adam2** » 28 Dec 2011, 20:47

I can only repeat that I have never found a 6 volt lantern battery to contain AA cells.
I have dismantled Duracell, Ever ready silver seal, Ever ready alkaline, and numerous cheap obscure brands.

I cant see why a manufacturer would make a 6 volt lantern battery from AA cells, 32 of which would surely cost more than the 4 D cells found in a cheap lantern battery.
Also the video at the begining of this thread appears to show the 32 AA cells simply sliding out of the dismantled lantern battery. This seems a bit unlikely. To achieve a nominal 6 volts from 32 AA cells would require that groups of 4 be connected in series, and that 8 such groups then be connected in parralel, alternatively groups of 8 could be connected in paralel, and the 4 such groups connected in series.
Either approach would seem to require either numerous soldered connections or some complex arrangement of spring clips, this would require some fairly detailed dismantling, yet the video shows the loose cells simply sliding out.

Post by **adam2** » 28 Dec 2011, 20:51

JohnB wrote:I think it's more useful to know how to replace odd sized and built-in batteries with something easily available!

Maplin sell a good selection of odd size cells and batteries, with a little improvisation one can often find something that will serve.

biffvernon · Post by **biffvernon** » 28 Dec 2011, 21:03

adam2 wrote: Also the video at the begining of this thread appears to show the 32 AA cells simply sliding out of the dismantled lantern battery. This seems a bit unlikely. To achieve a nominal 6 volts from 32 AA cells would require that groups of 4 be connected in series, and that 8 such groups then be connected in parralel, alternatively groups of 8 could be connected in paralel, and the 4 such groups connected in series.
Either approach would seem to require either numerous soldered connections or some complex arrangement of spring clips, this would require some fairly detailed dismantling, yet the video shows the loose cells simply sliding out.

Indeed - I found that part of the video unconvincing - which is why I posted on here. My facebook friend's story sounds more authentic. Maybe there used to be batteries made this way?

mobbsey · Post by **mobbsey** » 29 Dec 2011, 04:57

Duh?

This is just another form of disposable cell consumption!

Recharging cells (almost ten years since I wrote that!) is still going to be way, way cheaper than buying multiple disposable cells!

I have a couple of torches that use lantern batteries, but they were a pain because they couldn't be recharged. Then I came across this, which allows you to fit D-cells into a holder to take the place of the single 6V cell:

Note: the link to the rechargeable cells sheet earlier is a very old document (we don't even host it on our site any more, this link is to a mirror site); Free Range Network are proposing to update it this year with more up-to-date information.

Post by **adam2** » 29 Dec 2011, 12:41

Use of 4 D cells in place of a lantern battery by means of an adaptor as featured above may save money.
The drawback is potentialy reduced reliability due to the greater number of connections, and the need to get all 4 D cells the correct way round, trivial for us, but beyond a suprising number of people.

In years gone by, the use of 4 D cells in place of a proper lantern battery would have been a backwards step as the 4 D cells would have had a lower capacity, and been no cheaper.

These days though, D cells are usually cheaper and often of greater capacity than lantern batteries.
D size duracells are 18 A/H but a duracell lantern battery is only 13 A/H*.
Alkaline lantern batteries are not widely available, most of those sold in the high street are zinc/carbon and will compare very poorly to 4 alkaline D cells.

*in the UK that is ! in the USA Duracell lantern batteries are 27 A/H and are cheaper than the 13 A/H ones sold here.
Energiser lantern batteries are 27 A/H even in the UK but are not widely sold.

mobbsey · Post by **mobbsey** » 29 Dec 2011, 15:05

adam2 wrote:Use of 4 D cells in place of a lantern battery by means of an adaptor as featured above may save money.

There's no "may" about it!

As they so ungrammatically say in the US, "do the math":
# Energizer PJ996 lantern battery, 1,100mAh, cost £5.29, so overall cost is £5.29/cycle
# Uniross RB100889 Rechargeable Battery D Size, 2,600mAh, 2 x £6.75 = £13.50
-- but the cycle cost has to be calculated factoring in the cost of the cells and the power to recharge them.

Difference in capacity is a factor of 2.4 (NiMH battery theoretically gives 2.4 times more), but let's call it 1.5 because of inevitable internal self-discharge when left unused for a while -- so we first divide D-cell cost by 1.5 = £9. Assuming 500 recharges (half the stated figure), and that it takes five times more power than it delivers to charge it, 1.5V x 2.6Ah x 500 = 1,950kWh, which at about 15p per unit of mains power will cost £292.50. Add the adjusted cost of the D-cells, £9, gives £301.50. To be fair, let's also throw in the cost of the holder, £5, gives £306.50. Then divide by 500 -- the total cost per cycle is £0.61p. (I won't add the cost of the charger because, assuming its charging lots of other cells, it's cost is fairly negligible per recharge cycle)

Therefore, the cost of using a standard zinc-carbon PJ996 compared to rechargeable D-cells in a holder is (£5.29/£0.61) 8.6 times more!
Even assuming some of the figures are out, an 860% difference gives a bit of leeway!

Actually, I'm paying a little bit more per cycle because I charge my batteries from the PV-powered system in my workshop.

What's more interesting is the resource impact. Assuming a cell battery produces a 250 times (there's no proper figure for this -- this is the factor I've seen used in LCAs) more waste material than it actual weighs (assuming 0.6kg/PJ996), that's 150 kilos of waste crap for per cycle. Assuming the same factor for rechargeable D-cells (assume 0.2kg for 4 NiMH D-cells), that's 0.1 kilos per cycle!

So, to return to my original point, irrespective of whether they're AA cells, F-cells or whatever inside the lantern battery container, it's still significantly cheaper and far less impactful to use rechargeable cells than single-use alkalines.