Must-have equipment for a van build?

Jeremy Kasmann wrote: Espar w/ the digital thermostat.

What kind of van do you have? Did you do install the system yourself?

Propex heater here. Yep, expensive up front, but we are really happy to have it!

I'd love to see good DIY alternatives to fiamma and ARB awnings. I have a few ideas, but have not seen any really well done DIY.

quote=Mike Brady>I chose not to charge my coach batteries from my alternator because of the cost of a high amp alternator for the Sprinter and the fear of messing with MB electrical. Have you not had any issues with charging dissimilar sized batteries (starting opposed to coach)?

We did using a Wirthco battery doctor and without upgrading the alternator It's no problem for a T1N, and with the solar the aux batteries are never that low to need much from the alternator.

I did the same with an aux battery in my previa, no solar. Works fine and runs the fridge 2 days without driving/charging on a 75ah battery.

Mike Brady wrote: What kind of van do you have? Did you do install the system yourself?

Sprinter/NCV3 and no, I had someone else do it. Seems easy enough to install if you have some DIY skills (not me).

Share your build mountainhick!

Sounds like people are interested in your specific 200W solar system that can run a 12V fridge pulling 1-2amps off DC current(correct?). It could be helpful to know:
*equipment used(size, brand name)
efficient wire gauges used to cut on line loss (ex. Solar cells to controller to battery to breaker to fridge)
*Batteries in parallel or series
*and maybe any minimum and maximum readings W*hrs output( know some prefer amp*hrs when dealing with battery systems)
Should not take long to write out with the experience of it already being built and used.

Lol you edited the post. Originally said,"Ours was $400 for 200W solar panel." That is where the confusion from the panel pricing comparison came from. The larger expense of the shared system is because it is a larger 4 circuit system, able to run 4 appliance(not necessarily at the same time). This maybe considered excessive to some along with the ability to use AC and DC current.

StuMM wrote:Share your build mountainhick! Sounds like people are interested in your specific 200W solar system that can run a 12V fridge pulling 1-2amps off DC current(correct?). It could be helpful to know: *equipment used(size, brand name) efficient wire gauges used to cut on line loss (ex. Solar cells to controller to battery to breaker to fridge) *Batteries in parallel or series *and maybe any minimum and maximum readings W*hrs output( know some prefer amp*hrs when dealing with battery systems) Should not take long to write out with the experience of it already being built and used. Lol you edited the post. Originally said,"Ours was $400 for 200W solar panel." That is where the confusion from the panel pricing comparison came from. The larger expense of the shared system is because it is a larger 4 circuit system, able to run 4 appliance(not necessarily at the same time). This maybe considered excessive to some along with the ability to use AC and DC current.

http://www.lightharvestsolar.com/catalog/item/8768050/9885604.htm ($415 for 235w kit)
Brand is Schuco (65x39)
Solar to controller - 10g
Battery to Breaker - 8g (i forget exactly)
Fridge - 12g or 14g (dont remember)

2 155aH Exide Marathon batteries parallel (like MtnHick I purchased these after they had lived their shelf life but have had no problems and there is no way I would have purchased two new ones as they are $500 a piece)

mountainhick wrote:quote=Mike Brady>I chose not to charge my coach batteries from my alternator because of the cost of a high amp alternator for the Sprinter and the fear of messing with MB electrical. Have you not had any issues with charging dissimilar sized batteries (starting opposed to coach)? We did using a Wirthco battery doctor and without upgrading the alternator It's no problem for a T1N, and with the solar the aux batteries are never that low to need much from the alternator. I did the same with an aux battery in my previa, no solar. Works fine and runs the fridge 2 days without driving/charging on a 75ah battery.

I'm curious to know if you can achieve charging your batteries fully with the alternator alone? From my understanding alternators can have issues fully charging deep cycles.

20 kN wrote: An alternator can easily charge any 12v battery to capacity. The problem is if you use an alternator to try to charge a fully discharged battery, it's going to pour it's full capacity into the battery to try to charge it (which is going to be over 100 amps). That's really hard on the battery and even harder on the alternator. You can smoke your alternator trying to do that. Accordingly, you need to limit the amount of current going to the battery to keep the load on the alternator reasonable. There are many ways to do that, all requiring a custom idea, but the easiest is to intentionally use undersized wire (e.g.g 12 AWG instead of 4 AWG). By using a wire too thin, the wire will heat up and provide a voltage drop, thus limiting the amount of current available to the battery. This will not prevent the battery from fully charging, but will limit how fast it can be charged. The downside to this idea is the thin wire may get hot, potentially very hot. Another idea (and this is what I do), is to plug the battery directly into the cig lighter outlet. In my vehicle, the cig lighter turns off when the ignition is turned off, so it wont kill my main battery. Since the battery has to pull juice through all the vehicle's OEM wiring, which is mostly thin gauge crap, it limits the charging to around 10A, which is fine for my application as I have a small battery. The upside to this option is all I have to purchase is a cig outlet adapter and some wire. About $10 off eBay. There are a million ways to do this, all of which involve adding some resistance to the circuit to create a voltage drop under load, but it's application specific and will require some innovation on your part and a very basic understanding of electrical engineering principles.

Holy fuck!

StuMM wrote:Share your build mountainhick! Sounds like people are interested in your specific 200W solar system that can run a 12V fridge pulling 1-2amps off DC current(correct?). It could be helpful to know: *equipment used(size, brand name) efficient wire gauges used to cut on line loss (ex. Solar cells to controller to battery to breaker to fridge) *Batteries in parallel or series *and maybe any minimum and maximum readings W*hrs output( know some prefer amp*hrs when dealing with battery systems) Should not take long to write out with the experience of it already being built and used. Lol you edited the post. Originally said,"Ours was $400 for 200W solar panel." That is where the confusion from the panel pricing comparison came from. The larger expense of the shared system is because it is a larger 4 circuit system, able to run 4 appliance(not necessarily at the same time). This maybe considered excessive to some along with the ability to use AC and DC current.

You can look on Sprinter forum, same user name. Coverage is incomplete, I do what I can when I can. I will eventually update that thread with more comprehensive info as we finish things and once the project is complete (Still doing cabinetry, curtains, windows etc. I am not going to repost it all here, nor do I have time or desire to compile and post the data you are asking for. The system monitor idiot lights have never gone from green to yellow (you can read the controller manual)and we have never had any trouble with the system.

Solar system came as a package from Renogy with MPPT controller. Looks like Mike has a similar deal there.

20 kN wrote: An alternator can easily charge any 12v battery to capacity. The problem is if you use an alternator to try to charge a fully discharged battery, it's going to pour its full capacity into the battery to try to charge it (which is going to be over 100 amps). That's really hard on the battery and even harder on the alternator. You can smoke your alternator trying to do that. Accordingly, you need to limit the amount of current going to the battery to keep the load on the alternator reasonable IF you plan to charge deeply-discharged batteries off the alternator. There are many ways to do that, all requiring a custom idea, but the easiest is to intentionally use undersized wire (e.g. 12 AWG instead of 4 AWG). By using a wire too thin, the wire will heat up and provide a voltage drop, thus limiting the amount of current available to the battery. This will not prevent the battery from fully charging, but will limit how fast it can be charged. The downside to this idea is the thin wire may get hot, potentially very hot. Another idea (and this is what I do), is to plug the battery directly into the cig lighter outlet. In my vehicle, the cig lighter turns off when the ignition is turned off, so it wont kill my main battery. Since the battery has to pull juice through all the vehicle's OEM wiring, which is mostly thin gauge crap, it limits the charging to around 10A, which is fine for my application as I have a small battery. The upside to this option is all I have to purchase is a cig outlet adapter and some wire. About $10 off eBay. There are a million ways to do this, all of which involve adding some resistance to the circuit to create a voltage drop under load, but it's application specific and will require some innovation on your part and a very basic understanding of electrical engineering principles.

designed a similar set up. Took a fuse tester, found a open fuse that energized when the car is on and turned off,when off (much like your cig outlet adapter). 16AWG from this fuse to a solenoid (solediod acting like a switch)
In general went something like:

• Car battery to breaker - 10AWG
• Breaker to soliniod - 10AWG

Solenoid has three connections

• soleniod to fuse - 16AWG
• soleniod to secondary battery -10AWG
• 2 -12V Batteries in Parallel - 2 to 4AWG
• to the ground!

Can leave it DC or attach to a inverter from there for AC Current
Wires would not limit current in this set up.

Ray Pinpillage wrote: Holy fuck!

Agreed, that's pretty scary.

Allowing the copper to heat up to add resistance is a bit on the crazy side. If that cable gets to hot it will start a fire. Just go buy a high power resistor from mouser.com the caculations are not that hard if you know the voltage from your alternator. V=I*R P = I*V

A quick google search states that the alternator should put out between 13 and 14 volts. If you want to limit the current to 10 A then 14v-12v = 2 v. V/I = R, 2/10 = .2 ohms. for the power 2*10 = 20 watts.

200mOhm 25 W power resistor

only if the breaker was for a sufficiently low current, if that is the case then yes the breaker will trip. If not you could have a problem on your hands.

This is why I just bought a second battery and kept the auxiliary system completely isolated from the van. Very simple and I didn't need to tax my brain that is entirely lacking in electrical know-how :)

jacob m s wrote:only if the breaker was for a sufficiently low current, if that is the case then yes the breaker will trip. If not you could have a problem on your hands.

Even with a breaker, controlling current flow via heat dissipation from a resistive connection, like using too small a gauge wire, is a major hack and really poor electrical engineering. It would also be enough for an insurance company to deny an engine fire claim.

Just properly add house batteries, its not that complicated. The 220A alternator in my truck will easily charge three car batteries without damaging it or the batteries.

fossana wrote: I thought this would be the case and originally went with denim insulation, but the foam is way easier to mount on walls and ceiling. If you cover the cut edges with tape (which also helps to contain the pellets) it doesn't squeak.

What type of tape did you use?

20 kN wrote: What type of tape did you use?

I used HVAC foil tape (probably an overkill).

fossana wrote: I used HVAC foil tape (probably an overkill).

+1 on foil tape

I have a transit connect and am currently modding it out looking for a roof vent, I like the idea of a pop up style that it can also let some light in. I don't want it to be huge and I am not mounting it in the center of the roof since I will have a roof box on the right hand side. all I can find is 14x14" which seems huge, a Fan would be nice but doesn't really matter to much as I would rather keep cost down. I am in Canada so if someone knows where i can get one here that would be awesome.