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Any danger in Parallel battery circuit? Answered

Hi, I have a voice recorder that runs on a 1.5 V AAA battery. I keep running through too many of them. I have more  AA batteries and I was able to figure out a  setup to run it off non-AAA sources. I was thinking of connecting 2 AA in parallel.

Is there any danger my recorder if I do that? Any power spikes  or other things that can destroy my recorder?


Well, yes, as a matter of fact.

All cells used in a parallel configuration need to have essentially the same state of charge, or the more fully charged units will attempt to charge the depleted unit(s). If a cell has faults it will pull all the others down, and if it has enough of a fault, it can damage the remaining cells.

So. my advise is to install only battery groups that have the same age and state of charge. That is, if it has five cells in parallel, then install five new, fully charged cells and replace them all at the same time when they've become depleted.

Similar considerations for re-chargeable units, although there are more rules involved when charging as well as discharging.

Should be OK as the voltage in parallel should still be 1.5. You should also get more running time between battery changes.

Is there a big brained pro out there who can confirm or deny this? Or maybe a few small brained ones connected in series/parallel?

There is some concern with paralleling rechargeable batteries because one inevitably gets more/less charge than the others, and a differently charged parallel battery does more/less work than it should and wears out sooner.  A toast battery (to not confuse with 'dead' uncharged) can do all sorts of weird things - act as a short circuit, etc).  This is a big concern with lithiums because they tend to do silly things like burst into flames when used in a circuit in parallel without a smart balancing charger.

Generally, for single use batteries it will just add to capacity and not cause any problems.

Its considered acceptable, certainly for lead-acid chemistry, but only if you use new identical batteries that age together. Putting a new battery with an old one is a recipe for disaster.


Yeah, I'd only pair up non-rechargeable batteries from the same package.


8 years ago

Don't bother putting the AAs in parallel, just use one.  The capacity of some rechargeable AAs is about 2750mAh, about three times the capacity of a rechargeable AAA.  Non-rechargeables are about the same ratio.

Do not connect voltage sources in parallel. They will 'see' each other as a load and drain eachother.

However this setup will not cause any damage to the recorder as it will only supply 1.5v and only the current drawn.

Have you thought about rechargeable batteries.

Not really true of batteries.... they'll quickly settle to the same voltage and tend to be drawn down in parallel.

Brains to the rescue!

If you can sneak a way to get 1.5v into the player via the battery compartment virtually any combination of batteries would cut it.  A single AA has (a guess) at least double the capacity of a AAA, and a C or D battery would have significantly more (roughly proportional by volume).

Should be fine. Or you could go up to a single C or D cell.

Or you could consider switching to good rechargable batteries. I'm not sure what's available in AAA, but I'm using NiMH AA's rated at 1850 mAH (admittedly, at 1.2 volts nominal rather than the 1.5 the disposables start out at). My (old) camera sorta demands these; it will flatten alkalines in minutes.

I'm not pro on the subject, but if you change your batteries, be sure to get the same voltage.