Building an Adventure Van

[Geek]

What are you using as a charge circuit for the marine battery?

[heffe]

I have it linked to the main with an on/off switch so I dont drain the main. That way I dont drain the main battery overnight.

Originally Posted by Geek

What are you using as a charge circuit for the marine battery?

[Geek]

Any type of charger or anything or are they just in parallel?

[ducnut]

Originally Posted by heffe

great build geek. BTW, you live in some beautiful country here. Good . regarding the sprinter, I put an inverter and marine battery under the passenger seat.

I know it doesn't happen often, but, batteries do explode. Furthermore, they off-gas. Having it inside the passenger compartment is not safe, IMHO. There are frame-mount battery boxes that are better options.

[Geek]

Originally Posted by geode

True, if it is a lead-acid battery. Not an issue with AGM batts.

+1 Absorbed Gas Mat batteries are sealed, do not off-gas, and are used like that all the time in RVs.

Under the passenger seat is a common place to put a house battery in the sprinter... the actual vehicle's battery is under the driver from the factory (although they do put a cover over it).

Some guys go for 2 6 volt batteries in series in the space due to charging characteristics. I've been thinking about doing a single 8D battery but the things are huge. there is a guy on Sprinter forum with 4 8D batteries.. they are the size of a twin bed

[Geek]

I appreciate your input geode

I'd like to start with something small & simple battery wise but scalable. That way Cheryl & I can try it out and see how we are getting along on 3, 4 & 5 day back country trips. At first it'll be just running the stereo, overhead ventilation fan, and charging cel phones/laptops... but when we get the kitchen built those needs will change and I suspect an on-board refrigerator might end up being our biggest draw.

We're lucky in Colorado that in the high country we rarely need any air-conditioning...

I do plan on sticking a solar panel on the roof eventually.

[Geek]

I just looked at the build sheet for my van.. I have a 220 amp alternator (M46) and a 100amp battery (EE8).
Do I have to take into account what percentage of that 220amp alternator is "spoken for" in operating the vehicle before I go with the 1/4 rule?

With this configuration, what size of house battery could I go with without having to screw with my alternator?

Would I just add the battery capacities together and then use your 1/4 rule?

220 amp * 4 = 880 -100amp stock battery is 780ah house battery is my maximum capabilities with this alternator?

The smart charger I'm considering has an alternator temperature gauge as an extra safe guard and will turn off the charging for 10 minutes if the alternator gets to a certain safety cutoff temp.

[mud]

Keep in mind alternators usually don't put out very well at idle. Keep this in mind as you consider how the system will get recharged, idling or driving.

[EvilClown]

Originally Posted by geode

Having done many many battery systems in boats, the one thing I'll mention is at some point you'll have to remove or move a battery. An 8D is a beast to pick up. Several Group 31's can offer the same total ampacity yet be easier to move, strap down, locate about the vehicle.

If you have reliable / regular recharging capacity / ability you don't need a zillion amp-hours stowed under the bunk. You just need enough amp hours stored to last two or maybe three useage cycles.

For your weekend use, the batteries will get topped off as you drive to the camping spot, and start getting recharged on the way home. How many amp hours do you need to get through Friday night to Sunday mid-day? Later you can add solar, or a small quiet Honda genset.

The cover over the battery is usually to keep it from getting shorted out by a tool dropping across the posts.

Originally Posted by geode

You can use 50% of the amp hours in a battery repeatedly and not damage it. A group 31 batt has about 110 ah (amp hours), so it can give you 55 ah and you won't hurt it.

To calculate how many ah you need, whip up an Excel page for your electrical budget and list everything you'll use, how many amps it draws, and how many hours per day you'll use it.

Once you have your list, you'll know how big a battery bank amp hour wise you need to have to go one full useage cycle. Then you'll need to ponder how many useage cycles you want to be able to go without some sort of recharge period. Since a recharge usually involves running an engine (engine = noise / smell), most folks like to put that off as long as possible.

An aux alternator is typically sized based on the battery bank size. Smart alts / regulators can do a much more efficient recharging that the stock alt that came on the Sprinter. You might want to look and see if anyone has made up a bracket kit for mounting a second alt, or is there a preferred high output alt that will bolt in in place of the stock alt. Ideally you want an alt that is about 1/4 the size of your battery bank. 400 amp hour battery bank = 100 amp alt.

One problem of replacing the stock alt is the vee-belt size. A 3/8" vee belt has problems surviving the load of a high output alt. Typically you need need a 1/2" belt. I have no idea what size belt your Spinter van comes with. Pully's and alt fans can be swapped out as need be, changing the belt size on your Sprinter would be more problematic.

Make sense?

You can also buy a battery monitor device that will track amp hours in, and amp hours out, so you'll always know the true state of the battery bank.

Originally Posted by geode

Swing by Sears, snag one of their "clamp-on" AD/DC volt/ammeters for $50.

Go home, rip it out of the theft-proof packing, and set it to DCA.

Open up the Sprinter engine box and find the main ground cable where it connects to the battery. Clamp the meter around the cable and start the Sprinter and turn on all the "crap" you normally use. Radio, headlights, etc. Read the meter, it will show you the draw the engine / van requires for normal use. Flip on the wipers, A/C, etc one by one and see what they add to the draw.

Then you'll know what you have available for "house bank" recharging.

Whatever is left over is what you can mulitply by 4 to get house bank size.

I think that temp sensor is supposed to go on the batteries to monitor them for over-heat. Not on the alt. At least that's how the one's I've installed have been designed.



Might want to check the specs on the alt / regulator. Is it "smart"? Or a typical automotive dumb one? Usually auto type regulators are designed to quickly replace the energy lost during startup, and then taper right off to handle running loads. The ideal would be if it has a "smart" reg and can do a proper job of recharging the house bank.

If the alt has an external dumb regulator you may well be able to plug in a smart reg and be good to go. If so, I'd leave the stock one mounted in place, and mount a smart one and plug in. That way you have the stock one right there available if the smart one ever dies on you.

And remember, keep the alt drive belt tight. If it gets "loose" it slips, and builds mucho heat in the alt pulley and hence the alt bearings. Dead alt bearings is very usually a sign of slipping belt.

All this make sense to you?

Dang, yer smaht!

[Geek]

Thank you for all the great input geode I really appreciate you taking the time.

The sterling chargers have a temp sensor for the batteries and another for the alternator.

Do you have any experience with any "battery to battery" charge systems?
http://sterling-power-usa.com/12volt...rycharger.aspx

they aren't cheap but they seem like they might be a pretty good solution if they work as well as they claim...

"The Sterling Power Battery to Battery Charger monitors the engine start battery, it will not start until the battery voltage exceeds 13 volts, then it waits for 2.5 minutes to ensure that some power is replaced after the engine is started. It then loads the engine battery down to no less than 13 volts. This enables the engine battery to still receive a charge and ensures the alternator works at its full potential."

[Geek]

I just received a "thank you package" from Mercedes Benz of Henderson.
I have to admit that my experience with the folks there was 100% positive.
Definitely a great group of professionals to work with.

[adiablolex]

Great thread here Geek, thanks for all the info on the van

while we are on the battery subject, you can always try to have a dedicated house alternator if the space exists. We have a similar set up in two of our work trucks, they both have big honking auxiliary alternators.
One of them is hooked to the house batteries via an inverter and the other one is just on the inverter. The one that has the batteries can run a rooftop AC unit along with fluerescents and some plugs for 6-8 hours on its own, the other one you have to leave the truck running and take your feeds straight off the inverter output, I believe they're rated at about 60A or so which is plenty for anything you need powered.

On my RV (old dinosaur) there's a complicated and heavy combination of house batteries, generator and inverter that can run for a long time on its own between all the systems. I always wanted to get rid of the high amp components and substitute the genset with solar panels, I've already got rid of the AC units and substituted all the lights with halogen, I'll see what my total consumption rate is and decide accordingly.

Staying tuned to this thread I'm sure you'll get there first

[pfb]

Holy cripes! We are ADVriders!

If you put a gazillion amp-hour setup in you rig, you're gonna get banned.

Take the the alternator output and battery capacity of a stock KLR, multiply by 20 (which is probably about what your OEM alternator and battery provide), and make it work! Yea, in true ADVrider spirit, you'll probably have to turn off the radio before you power on the GPS plotter....

[morini-ford]

Originally Posted by Geek

What are you using as a charge circuit for the marine battery?

Used the Victron Cyrix intelligent combiners ( big picture http://batterietechnik-online.eshop....XXXXXXXXXX.JPG

They are availabe from 80A to 400A ( circuit on https://www.fraron.de/battery-combin...ml?language=en )

BTW : nice gift from Mercedes, didnt get that from Ford.

[cornercarver]

A small rooftop solar panel may well obviate the need for battery storage capable of multiple cycles. My van came with the crappiest little solar panel that I just toss up on the roof when stopped and plug into the solar charging circuit and I can keep myself in light, tunes, and charged camera batteries pretty much indefinitely. I know a lot of folks hate 3 way fridges that can run off propane, but my van came with one and I really like it. My 15 gallon propane tank lasts absolutely forever and gives me refrigeration, cooking heat, and hot water (not that I ever turn the water heater on, but it is there if I want to). I don't really know what the objection to propane fridge is, since mine works really well and stays damn cold on propane (plenty cold enough to make ice for my drinks). If I had to run my fridge off of the inverter or 12V, I'd need a lot more battery/charging capacity. I switch the fridge to 12V while I'm in motion and run it on 110V if I'm at home or have hookups.