A Good, Portable 12v Battery ?

[jsoceanlord]

Instead of lugging a 12 volt car battery from my home, where it sits on a maintainer, to my boat all the time, I'd like to buy a portable 12 volt battery. It just needs to power my
VHF radio and occasionally the bilge. It should be rechargable with my solar panel. Any ideas ? I didn't really see anything on westmarine.com or defender.com. It sounds like a sealed lead acid battery might work. thanks.

[GordMay]

What is the estimated daily output of your solar panel?
What is the time between trips (VHF radio usage)?
How often (& for what duration) does your bilge pump run?
If you don't want to lug it back & forth, why do you want "portable"?

[denverd0n]

Yeah, I'm a bit confused. You have a solar panel on your boat? Then why do you have to lug your battery back and forth?

As for portable batteries, you might want to look into a motorcycle battery. The problem with that will be that it will be a starter battery, not deep-cycle. Be aware, also, that battery capacity is directly related to weight, so a lighter portable battery is going to have less capacity.

And then, "portable" is a very subjective term. My brother-in-law would probably consider a 200 lbs. battery quite thoroughly "portable," but for me if it weighs more than about 30-40 lbs. I wouldn't want to be lugging it around all the time.

So, more information would probably help to get you more useful answers.

[Badsanta]

Your bilge pump wont work when your battery is at home. Are you not concerned that the boat will sink while your gone?

[hugosalt]

jsoceanlord, Don't let the guys scare you away...they really want to help...i think!...sounds like you have nothing set up now and would like to set up your solar panel to maintain a battery...
instead of taking home to recharge...lead acid would do, but it
sounds like you want a "deep cycle battery". As indicated above
you really must have a sense of your panel output and usage
before you can size...and remember you don't want to run battery down more than 50 % of capacity...for that will shorten
life of said battery. You did not mention starting a motor or
navigation lights...no power needed for motor is ok...but simple
set up for nav lights is always a good idea...many a day sail has
ended up in moonlight...by the way(depending where you sail) if a small solar panel is your only source to recharge, you
may have to occasionally take your battery home to top off...
therefore you may still refer to it as a "portable" battery.

[Chipg]

I have one of these: Amazon.com: Duracell DPP-600HD Powerpack 600 Jump Starter & Emergency Power Source with Radio: Automotive and love it, not sure if it's what your looking for but it also doubles as a power source for 110v things like a laptop on a beach, I have had mine for a couple years and have beat it to death and it still holds a charge like it is brand new. It's also great for emergencys and just to have.

[Starbuck]

Ocean, tell us more about your boat and the way you typically use it. The quality of feedback you get will jump orders of magnitude. As it is, we're left to guess at a lot.

What kind of boat is this (make, size)? How long does the boat sit between uses? How big a solar panel? Boat stored in or out of the water? You're a daysailor, right? Any plans at overnighting? Does this boat have running lights, and are they in working order?

Anything else you think pertinent will be appreciated.
Jeff

[magicbuzz]

Given that weight is directly related to capacity, it would be hard to find a 'portable' 12V battery unless your needs were relatively small. I have a trailerable 16' sailboat I have just put an electric motor on and so I got a 'deep cycle' AGM (VRLA battery - Wikipedia, the free encyclopedia) battery that is 'luggable' from the house to the boat. It is a 100 ampHr batt and takes quite a few hours to charge from the mains so realistically I think solar charging it would only ever be 'trickle charging'. I have no exact handle on my motor run duration yet but I've told roughly 5-7 hours.

[dohenyboy]

WM used to sell a small agm battery, light, portable, but no more
the smallest AGM I see around is group 22 and it costs $150 or more
You can get a cheap "deep cycle" wet cell battery at Wal Mart for $65 or $75