Can/should you store batteries backwards

[I_rv_too]

Have a couple of lights in my car and RV that are always turning themselves on ... with the end result that the batteries are dead when I go to use them.

I've taken to storing the batteries in the various lights backwards ... reverse of the way they should be inserted.

Question is ... is this a good thing or a bad thing?

 

[x-ray]

I'm far from an expert but I think I read somewhere that it is best to reverse just one of the batteries.

This may be some sort of safety measure to avoid frying a LED with reverse polarity for instance.

 

[Doug S]

Best is just to insert an insulator somewhere in string of cells. If number is even, you can reverse half of them. Any arrangement in which some number of cells other than half are reversed can risk cell damage and even explosion.

 

[this_is_nascar]

With all due respect, have you considered getting lights that do not turn themselves on?

 

[Saaby]

I have a blinky LED thing and when I am not using it instead of taking the batts out (cause I am too lazy) I just put in my own little "pull" tab made of a piece of scotch tape folded over itself.

 

[lightlover]

I'm pretty sure it's actually DANGEROUS to store cells in +ve to +ve.

Doug S,
isn't it possible to cause damage although the cells are even in number.
I seem to recall that if 2 cells were left in circuit and in reverse polarity that it could damage them, or cause fire/explosion ?

Jahn

 

[dano]

...Moved to Electronics, batteries incl...

--dan

 

[Wingerr]

If you're doing this on an incandescent light, I'm assuming the contacts on the light are not connected when the batteries are reversed, otherwise, it wouldn't make any difference.
If it's an LED light, it wouldn't be a good idea to reverse all the batteries, due to the reverse polarity mentioned.

If you flip half of the cells, and they're at an equivalent state of charge, it shouldn't be a problem, because if the light switched on, it would basically just connect the batteries in parallel, and no current would flow. If there's an odd number of cells, or the batteries are not equal, for some reason, the stronger cells would end up charging the weaker ones. Unless you had a really mismatched set or odd number of cells, even that shouldn't be much a problem.

 

[Doug S]

Originally posted by lightlover:
I'm pretty sure it's actually DANGEROUS to store cells in +ve to +ve.

Doug S,
isn't it possible to cause damage although the cells are even in number.
I seem to recall that if 2 cells were left in circuit and in reverse polarity that it could damage them, or cause fire/explosion ?

Jahn

<font size="2" face="Verdana, Arial">If one half the cells are reversed, the sum of voltage through the whole string is zero, therefore if the light is switched on, no current can flow. No risk to cells.

 

[lightlover]

But if they were slightly mis-matched, that could be problematic.
An electrical friend of mine mentioned this as a problem once, long ago. I'll try to get the details.

Jahn

 

[hotfoot]

Electricity will flow as long as there is a difference in potential. So, even if one battery is a teeeny bit more charged or has slightly higher voltage, things will happen. How fast it happens depends on how much difference there is. It's better to keep an totally open circuit if you intend to store the batteries for any extended period of time.

 

[machspass]

I agree, reversing batteries is not a good idea. I put a small piece of paper in between the top cell and bulb contact. When I want to use it, I simply move the paper, but leave it in the flashlight housing for safe keeping. I also do this with walkie-talkies that I don't use for a while.

 

[Wingerr]

If they were only slightly mismatched, the voltage differential of, say .1V would result in negligible current flow. If there was any mismatch, it would equalize fairly soon anyway, so it's not something that would go on until it all discharged or blows up. (This is assuming, of course, this isn't the AA-N type of setup where you're running different batteries) It's just a matter of convenience, not needing anything else to isolate them; but if you CAN put an insulator inside it, which should be easy enough, sure it would be better. For that matter, just get saran wrap or something, if it'll fit, so you can protect the flashlight from leakage should they decide to take a leak. Or get a ziplock bag and just store them separately, if you're not moving them around all the time, like trunk duty. That way they won't accidentally discharge or leak in the light.