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Battery power Answered

I have a battery powered laser on top of a spinning disc. This laser runs out of battery fairly quickly, I need to make it last longer somehow. Could I wire the laser to multiple batteries to make it last longer? If i manage to find a mains powered laser then it spinning constantly wouldn't work as it would have a wire.
I ideally need to find a way to power this laser (probably 2 lasers) for most of a day with something that fits on a fairly small spinning disc. Any ideas?




8 years ago

You can just join a bunch of batteries in parallel and power it that way.

How many mW is it? You could have a coil(s) of wire on the disk (along the periphery) and some permament magnets stationary outside the disk, inducing a current on the coils, and use some capacitor filtering to power the laser diode.


Reply 8 years ago

The lasers i'm trying out for the project are 1mW and 50mW but for the final thing i think i'll use 5mW.
If i buy a 4 AAA battery pack or even 2 are they connected in series or parallel (will that work?)
Thanks for the help and that second suggestion is definitely an ingenious answer but it may be a little bit to complicated for me to set up.


Reply 8 years ago

it'd actually just be easier to use 2 bigger batteries, such as 2 AA (instead of AAA) in series. should provide ~2x battery life or even more

If you would like to use a rechargable, I'd suggest using something lithium based for weight and longevity, possible something like a cellphone battery with a diode in series (to drop 3.7 volts to 3.0 volts).

I suggest a cellphone battery because I'm assuming you want thin if it's spinning on a disk, and they're widely avaiable. Just be wary when buying rechargable batteries, read full reviews and too good to be true deals for batteries are typically true. Also, (generally) never get non-oem/aftermarket cellhpone batteries. The capacities are typically 5x less than advertised and have an extremely short life span.

Many lower cost batteries have falsly high mah ratings.

not to advertise, but Japod cellhphone batteries have high capaciy densities, and are accurately rated, and fairly priced:

a generic cellphone battery charger will cost 2-3 dollars on ebay.


8 years ago

What kind of batteries where you using? Some, although pricey, last a lot longer then standard ones.


Reply 8 years ago

Thanks. It takes 2 AAA batteries, I think I need to use rechargeable batteries so I don't have to buy my weight in batteries, which are fairly long life anyway but I just want a way to extend this further.


Reply 8 years ago

If this "gadget" is going to be operated outside, a solar cell assist recharger could help with the rechargeables.....but they tend to be a tad lower in voltage then normal batteries, while Li-ion batteries may last a bit longer. The one I have in my portable digital recorder lasts me nearly half a year, as compared to a month with the alkaline batteries.