power supply question

[MartinHazel]

I need to build a 30a Power supply that will run of batteries if possible a lot of the work I do is isolated in location, and the radio I need to power requires 22a, has anyone got any ideas of a quick and easy way of doing this. I also run this kit from home but I'd like to keep my bills down as well so portability is also an issue. I'd really appreciate it if anyone has any thoughts on this

 

[blueroomelectronics]

How many volts?

 

[Mikebits]

Are you sure about that 30A requirement? That is a lot of power. Is this for an HF transceiver?

 

[blueroomelectronics]

I wonder what they mean by portable?

 

[MartinHazel]

To answer the questions above
13.8v
Yes its for a HF Transciever
By portable I mean I don't want to have to cart a trailer or 1/3 of a tonne with me (yes I know it won't be that bad but)

Martin

 

[blueroomelectronics]

Just buy some SLA batteries. As many as you can carry.

 

[Willbe]

To answer the questions above
13.8v
Yes its for a HF Transciever
By portable I mean I don't want to have to cart a trailer or 1/3 of a tonne with me (yes I know it won't be that bad but)

Martin

lead acid = energy density of .09 MJ/kg
12v @ 60Ah = ~20 kg. but at that high rate of discharge you won't get the full 60/22 = 2.7 hours.

 

[Hero999]

Use Lion batteries but expect to pay more.

 

[Sceadwian]

How much transmitting time are you looking for? You said peak power but you didn't mentioned anything about the transmission duty cycle. Li-poly will be the lightest weight longest run time configuration but you'll need a relatively sophisticated charge monitoring circuit and regulator. A 4 cell li-poly pack will output close to 15 volts and discharging has to be monitored preferably on a per cell basis to prevent cell damage.

Simplest solution would be 2 or 3 deep cycle marine batteries in parallel to give you plenty of run time and peak power. Deep cycles are preferred to standard lead acid batteris if you plan to run them down because 'regular' batteries anodes are thinner than 'marine' batteries and so they don't last as long if you discharge them most of the way. Marine batteries are ment to be used to drive things like boat radio's lights and electric trolling motors and discharge to a much further degree and still be rechargeable frequently.