[Mobile-Portable] Big Farad versus Hybrid Caps?

[kd4e]

If my battery is fully charged and is rated at 155 Amp Hours 
(20 Hr Rate)
and can provide 75 Amps for 77 Minutes and I put a 20A (or 
larger) float
charger across it *and* buffer it from surges with a huge 
capacitor why
would I still see low voltage?

In a mobile environment I would have an even larger source 
of float-
power across the battery (when the engine is running).

In SSB (intermittent service) I don't see a reason for 
concern - perhaps
in digital (semi-continuous/pulse service) I could see a 
concern.

What am I missing?

>    It would be wise and prudent to check the amplifier specs for  operating 
> voltage range. With that level of current draw, the battery  voltage may 
> well sag under load to less than what the amp wants in order to  operate 
> properly and an extra outboard capacitor probably won't help  enough.
>    Another (better IMHO) approach would be to use a battery  voltage boost 
> device. I assume that some are made in that current range.
>    Are you trying to avoid using a power supply because of cost,  or are 
> you just trying to be independent of AC mains?
>  
> Joe N1KHB

-- 

Thanks! & 73, doc, KD4E
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