Hello. I'm new here.I'm helping someone design a hand-held device. The load will draw about 350W for 5 seconds, but only once a day. The voltage is ideally 48V, but we could consider 24V or 12V but nothing lower. I am having trouble finding a small (guess - 4" x 1" x 1" ) rechargeable battery that could meet these requirements. This is a very low Watt-Hour application, and most batteries seemed to be design for as high a W-H as possible. Anything I've found so far that can meet the Power and Current requirements, even for a short duration, has far too high W-H capability and thus too large a size.

Any suggestions would be greatly appreciated.

Thanks

 

Hello. I'm new here.I'm helping someone design a hand-held device. The load will draw about 350W for 5 seconds, but only once a day. The voltage is ideally 48V, but we could consider 24V or 12V but nothing lower. I am having trouble finding a small (guess - 4" x 1" x 1" ) rechargeable battery that could meet these requirements. This is a very low Watt-Hour application, and most batteries seemed to be design for as high a W-H as possible. Anything I've found so far that can meet the Power and Current requirements, even for a short duration, has far too high W-H capability and thus too large a size.

Any suggestions would be greatly appreciated.

Thanks

Size for size - nickel cadmium has comparable instantaneous current draw to lead acid. But lousy Ah rating and fast self discharge. They're also just as heavy.

There are various SLA batteries that might get the job done, but lithium is lighter if you can accommodate safe charge management.

 

The Tadiran TLM-battery series might give you an idea of what's possible with lithium based.

http://www.tadiranbatteries.de/eng/...al-oxide-batteries/background-information.asp

 

Hello. I'm new here.I'm helping someone design a hand-held device. The load will draw about 350W for 5 seconds, but only once a day. The voltage is ideally 48V, but we could consider 24V or 12V but nothing lower. I am having trouble finding a small (guess - 4" x 1" x 1" ) rechargeable battery that could meet these requirements. This is a very low Watt-Hour application, and most batteries seemed to be design for as high a W-H as possible. Anything I've found so far that can meet the Power and Current requirements, even for a short duration, has far too high W-H capability and thus too large a size.

Any suggestions would be greatly appreciated.
We used a set of four 7-amphour gell cells to deliver 100amps for about 45 seconds, running film cameras and a floodlights for recording vehicle crashes. The lead-acid batteries will deliver a very large current for a short time and last a fair while. But the voltage does droop fairly rapidly, we had to use 3 batteries and a series voltage regulator to hold 24 volts for 45 seconds.
Thanks

 

We used a set of four 7-amphour gell cells to deliver 100amps for about 45 seconds, running film cameras and a floodlights for recording vehicle crashes. The lead-acid batteries will deliver a very large current for a short time and last a fair while. But the voltage does droop fairly rapidly, we had to use 3 batteries and a series voltage regulator to hold 24 volts for 45 seconds.