My super simple, single battery solution... or... good thing I have AAA

[con kso]

Here's what I've got going on in my Baja Ramble Machine known as CON KSO:



We picked up the 60L ARB fridge to free ourselves from the ice cube conspiracy. I'm assuming it will pull somewhere from .5 amp/hour to 2.0 amp/hour. So for my purposes I'll go with the 2.0 amp/hour. So multiply that by 24 hours = 48 amps. How am I doing for calcs so far?

I replaced my vehicles starter battery with this:



A Sears Diehard Marine Platinum 31 series battery with 100 amp/hours of capacity. So, I should be able to safely keep my ARB alive for a day based on my previous calculations. I'll have used 48 amp/hours of the 100 amp/hour capacity so I will have discharged the battery less than the recommended 50% that keeps it in its happy place, right?

Well that would be great if I was only hanging out for 24 hours. So, I purchased this:



Zamp Solar, 120watt portable solar system with the new controller. I also purchased the West Highland White Terrier upgrade which I would highly recommend to anyone interested in the Zamp- call Jeff in Bend to see about availability- easily adds 3 MegaAmp/hours to the system.

I had read that I could have gotten away with a 60watt system but I said screw it, let's double that to account for inefficiency etc. So according the the literature that came with the panels, it should produce 50 - 60 amps per day. So if I go with the low figure of 50 amps per day, my battery, when hooked up to this system should be able to keep up with the ARB's demands (48 amps/day) with 2 amps/day to spare. Right?

And just because I don't want to be left unable to start my rig deep in southern Baja, I bought one of these to carry along:



This thing is pretty nifty, it can be charged while driving along from cigarette lighter or charged at home. It also comes with charging bits and pieces and some mini jumper cables. The reviews about it were pretty positive. Here's what's inside the case:



So in summary here's what I think I've accomplished:

1. Provided enough battery to run my 'fridge indefinitely.
2. Provided a battery that is wired close enough to my alternator to get charged while I drive.
3. Provided enough solar power to keep things nicely charged.
4. Provided a back up jump start system in case I made the ASSumption mistake.

So where did I go wrong?

 

[DiploStrat]

So where did I go wrong?

Field test it. Does it work? If so, ignore the rest of us.

N.B. 1: There are going to be some other loads on the battery, probably trivial, but loads none the less.

N.B. 2:The rule of thumb that I have always followed is 20-30Ah per day per 100w of solar under good to perfect conditions, e.g. a sunny day in Baja, so I would guess that 60Ah from 120w is very optimistic. But again, don't rely on the Internet; test it for yourself.

N.B. 3: Lifeline, at least, notes that you can exceed the 50% rule IF, and this is a big IF, you recharge the battery immediately. So if you drew down 60Ah overnight and started your engine or got strong sunlight the next morning, you should be fine. This would not be the case if you drew down 60Ah overnight and then left the battery discharged for a week.

Final N.B.: The 50% rule is just a rule. A good one, but only a guideline. You might decide that the simplicty of using only a single battery was well worth the cost of having to replace that single battery a year earlier than you would have had to replace it had you gone to a full blown double battery system.

Other than that, I prefer Shepherds to Westys.

 

[con kso]

Thanks Mr. Strat!

Now that you mention it, there will be additional draw on the battery- I will intermittently power up my water pump that gives us water pressure for my on-demand hot water heater for daily showers. I ran the pump off my other car battery for three days of showers without depleting it enough to require a jumpstart on my last Baja trip we'll see how it affects my amp/hours this time.

My field test begins tomorrow. We're out of here at 5am. I'll be running the ARB from Monday morning until we return home which should be the following Sunday. I'm hoping to never have to jump start the vehicle.

I will be running the ARB at high capacity because I plan on drinking a lot of beer. And I like my beer to be cold.

I will report my findings.

German sheps are great dogs- how do they affect amp/hours?

John and Liza

 

[DiploStrat]

German sheps are great dogs- how do they affect amp/hours?

We found our hounds to be a net source of heat!

Sadly, all have passed on, so we travel with a cat. (Also a heat source.)

Have a wonderful, safe trip.

 

[mdmead]

I like the comment above about field testing it. One other thing... You can fire up the truck daily and top off the battery fairly quickly.

 

[uscg2008]

I have a pelfreybilt battery cage holding my battery. Very solid no chance of the battery moving around.

 

[fireball]

Do some reading on the most efficient ways to pack that fridge and buy the cover for it. My grp24 battery can go for almost 3 days in the middle of summer powering our arb 63.

 

[con kso]

Thanks for all the tips and feedback- I'm fired up to try it out. Just got finished connecting an SAE extension to the battery that allows me to plug in to the battery without lifting the hood. The plug is seated where my foglights should be- came out pretty clean.

USCG... is that battery box in a Tundra???? That box looks sweet! Did you have to extend your battery cables to get them onto the larger poles? I had to take off the clamps and drill out the eyes on the clamps to fit the smaller poles. If that box is on a Tundra, was it an easy install- super curious about that because the stock clamp is pretty small for a 75lb battery.

I think I did a good job of packing it, I filled it with Karl Strauss Red Trolley Ale, some Kona Brewing Company Longboard Island Lager and some good ol' Pacifico. My girlfriend's pissed because evidently I didn't leave any room for food.

Once again, thanks for all the input. Stoked!!!!

 

[wrcsixeight]

You cannot fire up the truck and top off the battery fairly quickly, unless you consider 4 to 5 hours of idling fairly quickly.

Chromed alternators included. Top charging a battery takes hours, no matter the charging source.

Surface charge voltage after a charging source is removed especially a high amperage charging source like an alternator, fools many people into thinking their batteries are fully charged when they are far from.

http://www.pbase.com/mainecruising/battery_state_of_charge

 

[CaliMobber]

You look like you have all area's covered and I would feel safe going into baja with that setup. Remember that the fridge will auto shut down when the voltage gets low so your even more safe. Ive had my edgestar kill my batteries a few times. I can tell the batteries are hurting when I start the truck but she always starts.

Yea the solar wont put out the full since losses and it wont always be pointing perfectly at the sun, but it should be plenty overkill for one day.

 

[Joe917]

Nice battery cage. It looks like none of the wires are fused. All positive wires should be fused as close to the battery as possible.

 

[uscg2008]

They are just behind the black box behind the actual battery I just didn't want all of them right next to the battery. But, I do have a blue seas 6 blade box that will be cleaning up the wiring some.

 

[uscg2008]

Thanks for all the tips and feedback- I'm fired up to try it out. Just got finished connecting an SAE extension to the battery that allows me to plug in to the battery without lifting the hood. The plug is seated where my foglights should be- came out pretty clean.

USCG... is that battery box in a Tundra???? That box looks sweet! Did you have to extend your battery cables to get them onto the larger poles? I had to take off the clamps and drill out the eyes on the clamps to fit the smaller poles. If that box is on a Tundra, was it an easy install- super curious about that because the stock clamp is pretty small for a 75lb battery.

I think I did a good job of packing it, I filled it with Karl Strauss Red Trolley Ale, some Kona Brewing Company Longboard Island Lager and some good ol' Pacifico. My girlfriend's pissed because evidently I didn't leave any room for food.

Once again, thanks for all the input. Stoked!!!!

no its for a Tacoma but it looks like it might be the same dimensions as the tundra. All I had to do was take off one of the black plastic clips that held the negative lead to give it a little more slack. I had to drill out one of the eyes as well. Here is what the box looks like apart.

In this pic you can see the new hardware that it comes with, all grade 8 if I remember right.

This is where I got it from. http://www.pelfreybilt.com/#!2005battery-cage/c50f
They have amazing customer service, and Mrs Pelfrey (Satin Pelfrey) is pretty good at getting back to you right away.

 

[BigSwede]

I had been looking at dual battery systems, but in the end I went similar to the OP. I have the same huge Group 31 Sears Platinum battery, with a LiPoFe4 jump starter for backup. I don't have solar, because I live in Minnesota, and, well, it just wouldn't be worth it due to the angle of the sun, trees in the way, etc. I am running an Engel MR040 fridge, and a CPAP (without humidifier) at night.

I recently got back from a 9-day Colorado trip. Every morning the Trooper fired up with no discernible difference to normal cranking speed. I guess I should have checked voltage in the morning for but I never did. Certainly never had to use the jump starter. Of course, temps were much cooler than Baja.

 

[StorminMormon]

Has anyone ever done anything like this with a diesel?

This is a great thread thank you for sharing this project.