Let's revisit this battery question...

[exranger]

I have a 50 AMP shore power connection.

One of the reasons I was/am considering this much battery is that I can avoid discharging much at all, percentage wise, while out, thus extending the life of the bank.

I have not seen 12 volt air conditioning around, is there such a thing?

As for the 12 volt marguarita blender, I am there with that!

[cal40john]

There are threads on the site about air conditioning.

Here's one.

http://www.cruisersforum.com/forums/...p-12245-2.html

Another thread that I'm not using the right search terms to find at the moment involves someone that put 800 amp-hrs on the boat to be able to use air conditioning for a night without using the genset.

John

[GordMay]

Originally Posted by exranger

... I have not seen 12 volt air conditioning around, is there such a thing? ...

A just got about 201,000 Google “hits” for < 12vdc air conditioning >.

[exranger]

LOL. I must admit, had not thought to google it, basically because I never thought it existed. Most of the hits aren't really for dc powered air, but there were more units available than I ever thought possible. The problem of course is that darn 30-60 amp draw! Maybe I could use those 800 amps!

One long night and you would draw down your 800 amp bank about 40%. Yuck.

[Tropic Cat]

Originally Posted by exranger

One long night and you would draw down your 800 amp bank about 40%. Yuck.

Yeah, but you'd have a very appreciative Admiral. This can be a very good thing.....

[exranger]

Yes, anything that makes the Admiral happier to be aboard is to be praised!! (The appearance of a manatee helps, too!).

[CorrinaCorrina]

I work as a marine electrician and I have seen quite the variety when it comes to people trying to charge their battery banks. To answer your question about will a 15amp three stage charger from walmart charge your 8D batteries..... YES! However with this yes comes a problem. Your battery bank is too much for this charger. Lets do some math. Three 8D batteries will give you aroud 660 amp hours. If you follow the rule of never going below the 50% level then you have aroud 330 amp hours of useable battery capacity. (If you want I can describe the proper battery range you want but I will not overburden this message with math.) If you take 330 and divide it by 15 then it will take 22 hours for you walmart charger to charge your battery bank. That is 22 hours your walmart charger is running at full capacity. That is a lot of heat and electrical equipment does not like heat. You would be better to look at a Truecharge 40 with a temp probe, Charles battery charger or Magnum charger/inverters.

[onestepcsy37]

i use a walmart charger. i bought the 35 amp 'smart' charger that gradually reduces the rate as the battery comes up. think i paid about 60 or 70 dollars for it. been using it for nearly two years now. here's my take -

we had intended to install solar panels and/or wind charger to supplement the engine driven alternator. at anchor, where cruisers spend a lot of time, i dislike running the engine to charge the batteries. but we ran out of time (and money) so i bought one of those chargers to run off my little honda eu-1000 gas generator.

my battery bank consists of four trojan t-105 golf cart batteries for the house bank and one trojan 12 volt battery for engine starting, combined total of about 550 amp hours. but i only use the house bank most of the time so call it 450 amp hours. in a typical 24 hour day we use 60 to 80 amp hours - most of it for the adler barbour fridge. each morning i check the battery voltage to see how much needs to be replaced and then run the charger off the honda - takes two or three hours and costs about a quart of gas. it's not as convenient as being able to just push a few buttons because i've got to open up the battery box and set up the generator and plug in the charger and connect the cables to the battery posts and all that but so far i'm willing to accept the inconvenience - not everyone's cup of tea.

i'm still going to install solar panels someday. should cut down on the number of times/hours i have to run the honda.

and yes, i do have an onboard charger that i can use at dockside but it's only rated at 10 amps.

[exranger]

Onestepcsy37, you are kind of doing what I was thinking about doing when I leave the dock to cruise. It's one reason I am looking at using maybe 3 of those 8D batteries.

[Badsanta]

I use 4-4D and what a beast to move, an 8D must be like 130lbs each. Ouch!! I think that when I replace mine, I will use alot of smaller ones. But 4 years and no problems. I may die first. I do like my solar. I wasted all that money on a charger I never use and I never plug in. But I dont go out over a week. Yet.