Car batteries ( let the beatings Commence) :(

[rustytoolss]

OK, I'm going to open a can of worms here. And I know what I should buy. But If you were working with my non existent budget. You would also be cutting corners.
At this point of my build, I'm thinking of my 12 volt battery needs (and family health expenses) . And I am thinking that for the first season for my TTT. I will have to use a 12 volt automotive battery, that I already have. I know that this is not the best choice. But it may have to be that way.
I have an RV electrical power box and the RV 110-12v converter. I will probably only be using my camper one 3-4 day weekend , that I would be relying solely on 12 volt power. (other times I will have access to shore power )
During my 12 volt weekend, All I plan to run is interior lights (as needed) and hope to switch them to LED's
How much lighting time could I expect to get from a full charged (used) 24 series car battery. (that I'm sure is a loaded question)
I'm hoping by the time I get to that 12 volt weekend, that I have come up with the extra bucks for a deep cycle or AGM battery. But I can not plan for that. So at this point.....sometimes you gotta do...what you gotta do.. So far I have gotten a lot of materials for free / or at very low cost to me. I've done quite well at keeping my cost low.
Let the Beatings Commence

[tony.latham]

I will have to use a 12 volt automotive battery, that I already have.

Let me lay the first blow of the beatings: Use the battery and change over to LED lights. You'll be fine.

Tony

[rustytoolss]

That was fairly painless... Sometimes life has away for changing your priorities . Does not mean you can not do the things you want to...just means, sometimes there may be more important needs.

[pete49]

As Tony says just change your lights to LED's and your good to go. A car battery that won't start a car still carries 12-13v so lights will last up to or longer than a week without problems they have just lost cranking amps. My used car battery out of my Nissan Patrol 4wd lasts over a week even using the radio at times. If you can stretch to a small solar panel even longer. Just do it and enjoy the serenity
Pete

[pchast]

I'm going to ask how many lights and what the rating is on the battery. But
I'll suggest you should be good for 3 to 4 days of light at night even with
that car battery.

[Cosmo]

I agree - a few days depending on the draw and the amp rating of the battery.
I would recommend you keep an eye on the battery voltage. Auto batteries can not tolerate deep discharge as well as deep cycle RV battery. Maybe someone here can recommend a minimum voltage you can take the battery to before recharging. Not draining the battery too deeply will make the battery last longer than if you drain it all the time.

I also agree with the LED recommendation. I swapped automotive bulbs with an plug in LED replacement. Power consumption for one bulb was 1.25 amps which dropped to .25 amps with an LED replacement. http://amzn.to/2ikCzU3

If lighting is your only need - you could skip a Lead Acid battery and go with portable lighting and rechargeable batteries. Might cost far less and be far more versatile.
http://amzn.to/2ikohTH
http://amzn.to/2ikjXnb
http://amzn.to/2jfBBI2
Friends give "Copper Wire"lights rave reviews http://amzn.to/2jGFz9q

I use ENELOOP rechargeable AA and AAA which save a huge amount of money.
One AA Eneloop can be charged 2100 times. If you are paying 35 cents a battery *for disposable batteries ONE Eneloop will save you $735. A 4 pack can save a WHOPPING $2900!!!
They also don't self discharge like old rechargeable's' used to do making them a good emergency battery.
AA ENELOOPS http://amzn.to/2jrjuwn
AAA ENELOOPS http://amzn.to/2jfwuHF

This AA/AAA recharger runs on 12 volt DC and AC 120 http://amzn.to/2jEaUto

I have used candles too.

Good luck and report back. I am interested in your results.

-Cosmo

[Wolffarmer]

I used a group 24 in mine for 7-8 years or so. and never killed it. But I use very little power anyway but it was still working when I took it out. I was going to put it a vehicle but the shop the battery was in burned before I got to that part of the project so I will never know.

Do what you got to do. I would suppose that if you can charge it up often it will not be to bad.

[dales133]

Im using standard car batteris in mine and i turned all the lights on and the stereo and amp on standby and still had 12.1v after a week

[dancam]

You can have a really good group 24 or really cheap. But either way it should last. Does it say how many amp hours it is? Is it sealed or can you check its water level before you use it?

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[daveesl77]

And another on the "did the same thing" line. Years ago my neighbor gave me the original battery his son took from his about 2003 Dodge truck. It sat in my garage for a few years. I'd charge it every now and then, but normally it just sat and would maybe be used to play with something that needed 12v. In 2012 I gave it a full, slow charge and installed it in my truck camper. Used that for a year (all lights replaced with LED). Sold the truck camper, battery went back in the garage. After another year or so, I built the Conch Fritter trailer and put the battery in that. In 2015 it still worked just great. Finally, this year, on our last trip up to Georgia in November, it showed it was getting old. Still ran the lights, but would barely charge up to 13 volts. So now, after I guess 8 or so years of me having it and at least 13 years of life, I need to replace a free battery that should have died long ago. Oh, that battery also did a 13+ hour test by running my dorm fridge from a cheap Chinese 2000 watt inverter, charged by a 50 watt solar panel. Test finally stopped when battery voltage dropped below 12v.

I've actually been trying to decide whether to go with the duration but weight of a true deep cycle, or just get another car battery. Let's say my first test of a car battery wasn't too bad. All my lights are LED. Only thing that draws a decent amount is when I fire up the inverter and run the dorm fridge off of 12v.

dave

[yrock87]

I think you would get a beating if you bought a new car battery for $60 instead of spending the $80 on an RV/marine. but to use what you already have that is free? no way, makes sense to me. as others of mentioned, if you switch to LED you will easily get 3-4 days of lights out of a car battery in decent condition. heck some people on the forum use jump boxes and others use the little wheel chair batteries and make it several days.

good luck

[rustytoolss]

Thanks for the good comments and good ideas.

[booyah]

I have a group 24 deep cycle, (75a c/20 cycle @ 12v) but the biggest power draw in mine is the fan.

The battery gives me about 900w total, or 720w at a 80% discharge.

If you're not running a fan 8+ hours, and you only use your lights as needed, i think you're fine. In my case the fantastic draws about 1.4a/hour, (17w/hour, for 136w or so per 8 hour night). Toss in the load from charging some electronics (a tablet or two, and a smart phone or two maybe 40w? ) and led lights as needed (5-10w), and I figure I can go for 3-4 days off that deep cycle without worrying about things. If your load consists of your lights and thats it you should be plenty fine.

Honestly mine would go farther as you can get better life with the lower current draw, but I really don't even want to draw it down to the 80% level, I like 50-60% if I can for a longer service life.

FWIW, I got mine from sams club for like $70 when you want to go to a dedicated camper battery.

[Donutboy]

I wanted a battery also, but didn't need a lot of power, and didn't want to spend a lot. Mainly to have lights if I need to stop enroute, or for a night or two at most. I ended up getting a 35 Amp Hour AGM deep cycle battery from Harbor Freight. $54 with the 20% off coupon. Smaller and lighter too! AGM was a requirement since mine was being mounted in the camper.

http://www.harborfreight.com/12-volt-35-amp-hour-universal-battery-68680.html

[vincigj]

I did the same as donut boy. 35ahr, led lights, sparing use of too big a fan.
Just go camping a see how the car battery does. When I was a kid used a car battery for a whole day on a trolling motor before I knew "better".


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