Radio battery backup

[ke7vvt]

Are deep-cycle batteries good for backup power for radio gear? I figure going to Checker or Autozone and buying the biggest battery would be the best way to do this. Checker sells a very large $125 "regular" automotive battery and a medium sized $75 marine battery, but rated in "cold cranking amps". I visited a local Natl. Battery store and the guy suggested an 18A hr sealed battery that looks almost exactly the same as in the link OARC - Ogden Amateur Radio Club for about $75 a piece.

I would assume that bigger is better, and less $ is better too. Since the power rarely goes out, I am inclined to get the super large $125 "regular" automotive battery instead of the medium sized marine battery.

What does everyone else use? Regular, marine, or the sealed type or something else? Any feedback is greatly appreciated.

 

[Captain Kilowatt]

Batteries meant for starting are not good for backup power. They are meant to provide a large amount of current for a very short time and then be charged up again immediately.CCA's or cold cranking amps means nothing when looking at backup power. You want reserve minutes which is what deep cycle batteries are designed for.

Deep cycle batteries are meant to be be discharged over a longer period of time while providing a lower discharge current.They can also be discharged below the safe limit for a regular starting battery and be recharged again without damage. deeply discharging a regular battery even just a couple times can result in it being damaged to the point of not accepting a full charge again.

 

[n9zas]

I've been using a 900cca marine battery from interstate for about 2 years and it works very well with 4 different vhf/uhf commercial and ham rigs plus a small studio fridge.
I keep it topped off with a 1 amp. motorcycle charger.
As said previously,the automotive batteries typically used in your car do not work well for this over long periods of time.
n9zas

 

[packrat]

Any lead / acid battery has two drawbacks...

1: High self-discharge rate.

2: Sulfuric acid outgassing.

I would use a spiral cell / gel cell type of battery. Very low self discharge and no outgassing to eat up your equipment.

JR

 

[Moleculo]

What they all said already.

The best ones that I know of are made by Odyssey. Optima Marine batteries are good, too. Unfortunately, they're not cheap. Keeping a regular, wet marine battery on a trickle charger will work just fine also, but you must check that water level regularly. If you've never done it, you'll be pleasantly surprised how long your radio will work for you at a modest power output level while on battery power.