Multiple batteries in toys

[Michael Yoni]

We have just spent a small fortune on specialised toys for our daughter (special needs toys)
what has me very perplexed is that most of them are run on 6 AA batteries (ie 6 *1.5v).

It got me thinking that why not simply insert a 9v battery rather than 6 AA batteries. I would imagine that a standard 9v would hold more power than 6 AA.

(I am talking batteries that are found in Australia).

So if I was ever so slightly electronically minded would it be save to cut the bank of wires to the power source, join them up appropriately and insert the appropriate 9v connector.
Would it not work and at least my power supply would be longer.
Thoughts.

Thanks
MY

 

[BobK]

6 AA batteries have about 5X the capacity of the standard rectangular 9V. If it worked at all, it would work for much less time on a single 9V compared to 6 AA.

Bob

 

[shumifan50]

You could go down the route of rechargable batteries like NiMH which directly replace the AA batteries, or you could look at the following link for Lithium batteries(NON_RECHARGEABLE) which give much longer life and are direct replacements for AA batteries.
NON-RECHARGEABLE LITHIUM BATTERIES

Because these are for toys for children, safety is also a big concern. The above suggestions take that into account.

 

[Michael Yoni]

Thanks for your replies.

That is why I ask such learned people.

When I say toys these are not toys in the sense of the average child being left with toys on the floor. These are somewhat specialised/medical toys which are connected to switches where the child presses a switch and the toy responds by way of light or movement/vibration or sound or a combination of all three. They are used under supervised conditions.

Many of these specialised toys do have a caution note on them regarding rechargeable batteries indicating that because a typical AA rechargeable is not 1.5v but less (they quote 1.2v) that the toys may not work efficiently after a few uses. I did think of getting rechargeable batteries and purchasing a few rechargers but think its probably easier for me to just get single use batteries.


Are there larger 9v batteries on the market (somewhat like those that one would see in model cars etc). I may have to go to Battery-world or similar.

 

[(*steve*)]

Battery capacity (in terms of power) for a particular chemistry is pretty much related to size and weight.

For the same chemistry, a battery needs to be physically larger to provide more power over time (i.e. to make the battery last longer)

A higher voltage does not mean more power.

AA batteries are a fairly good compromise between cost and power for small appliances. They tend to be way better than 9V batteries.

 

[Michael Yoni]

Thanks,
Makes it very clear.

We have decided to go with the Lithium ones. Yeah more expensive but if we find that its becoming too expensive them will revert to the heavy duty ones.

E-bay seems to be far cheaper.

MY

 

[shumifan50]

SOME CAUTION:

There are several types of Lithium batteries. The rechargeable versions work well and can deliver very high currents, but they are somewhat dangerous as a short during use or incorrect charging can cause a fire. The non-rechargeables is a direct replacement and safe(says the manufacturer).
Rechargeable Lithium Polymer (LiPos for short) are not - the have a voltage of 3.7V per cell, so it is not possible to achieve 9V and you would have to check with manufacturers whether the toys can handle 11.1V (3S LiPo). You have already indicated that the toys don not handle low voltage well. LiPos are cost effective and used extensively by radio control hobbyists.
If you go the LiPo route, you have to buy a specialised LiPo/Li-Ion charger and do not skimp, get a good balance charger as you will be using more than one cell.

The only other question:
Would it not be possible to use a power adapter that gives 9V? Get one of those that has the whole voltage regulation in the wall plug so there is no high voltage beyond the plug.