Do not use rechargeable batteries. Why not?

It’s just a light up wine bottle that takes 3 aaa batteries.
The ladeeez in the shop are convinced the world will end if I put them in.

Our central heating controller is the same. I think it’s because rechargeable batteries are closer to 1.2v than 1.5v so might not actually power it.

light up wine bottle

It makes the Chateau Lafite come alive.

Some things that are very sensitive won’t work because as above the voltage is lower.

In things that take a reasonable amount of power the voltage of alkalines will drop to a similar level to that of rechargeables when the power is on (because of the high internal resistance, because physics) so they end up delivering more or less similar voltage.

However with low currents, the voltage difference is greater. So if something is designed specifically with 1.5V requirement it wouldn’t necessarily work with 1.2V. Battery powered clocks with a single cell don’t work on rechargeables, afaik, not sure about remotes either.

If it’s just a light though, well, it might not work – but it might. It’s definitely safe though and definitely won’t damage it.

light up wine bottle

Because it would be a waste of any type of battery, even dead ones? :-)

NiMH batteries have low internal resistance, so if it was short circuited, it could give very high currents. So this could start a fire, or explode.

dribbly wine onto contacts short-circuiting cells – worse for rechargeables than “ordinary” cells, I think

Why are rechargeable batteries 1.2v instead of 1.5v?

I’ve got a few AAA torches that need non-rechargeable batteries which is a pain, but rechargeable ones only last about fifteen minutes before going dim instead of a couple of hours…

Different chemistry. NiMH instead of alkaline.

It’s just the way the chemistry works. nicad and nimh are both about 1.2, li-ion are 3.7, lead-acid 2.1 (6 to a car battery), button batteries aaround 3.2 I think and good old alkalines 1.5.

i don’t think I’ve ever had a problem using nimh in place of alkalines but I realise it could matter.

I think it just goes back to the days of NiCds and the best they could get out of them was 1.2V and now we are stuck with it but I suspect most modern ones will be near 1.4V when fully charged. Just try it.

but rechargeable ones only last about fifteen minutes before going dim instead of a couple of hours…

Are they freshly charged? Normal recarbs lose charge over time, not really ideal in an occasional-use device. Get some Eneloops, they don’t do that.

They were freshly charged, and I tried two chargers; it could have been something else, but I only tried it a few times before giving up on it and getting an 18650 torch instead.

Hmm – part of the problem here is that the specified voltage for rechargeables is measured at a different point to alkalines. 1.2V is a mid discharge voltage, whilst 1.5V is close to full charge for alkalines (in reality most will be nearer 1.6V nowadays). Fully charged NiMH and NiCad are both about 1.4V, though they won’t sustain that voltage as long as alkalines will.

The other issue is crap electronics – if it won’t work with rechargeables then it will also stop working with alkalines when they have provided less than half of their energy.

So will I die or not?

Yes, you will, sorry

I’ve used all types of the above mentioned batteries in all types of appliances/toys/remotes yet I’m still alive and never had firemen at my house.

I doubt you’ll die.

I’ve got a few AAA torches that need non-rechargeable batteries which is a pain, but rechargeable ones only last about fifteen minutes before going dim instead of a couple of hours…

I have a number of small flashlights that will use a bog-standard AA, but will also take 14500 Li-ion rechargeables, at 3.7V, and they work really well, same batteries can use a 18650 charger.
http://www.dx.com/p/trustfire-r5-a3-cree-xp-e-r5-3-mode-230-lumen-memory-led-flashlight-1-aa-1-14500-39062

CZ, I trust you on all things torchy. Do you have any sort of layman’s definitive guide as to how the CREE naming scheme works? R5, Q4, S7, WTF?

What on earth is a light up wine bottle?

It’s a plastic wine bottle with light up stars in it and a suitably slushy message written on the front.Ladies love them and we sell shed loads of em.
When we have them lit up on display the ladies in our shop want to use non rechargeable batteries which run out when they forget to switch them off at home time. That’s why I want to use rechargeables.

When we have them lit up on display the ladies in our shop want to use non rechargeable batteries which run out when they forget to switch them off at home time. That’s why I want to use rechargeables.

If you put rechargeables in and forget to switch them off at home time you’ll soon knacker them.