Roadtrek generator retrofit

[avanti]

Originally Posted by ManWonder

As a relative newbie, I've been wondering why folks are okay with adding a second alternator - which requires running the engine to operate but - if you're going to have to start the engine it does seem you could just then turn on the van's built-in A/C.

True. Be aware, though, that extended idling of modern diesel engines is controversial, due to DPF issues. I personally would not idle my Sprinter all night. I think that second engine alternators only make sense in an RV if you drive more or less every day, as we do. Under this scenario, a second alternator can give you a substantial charge MUCH faster than any other option.

[BBQ]

Originally Posted by ManWonder

As a relative newbie, I've been wondering why folks are okay with adding a second alternator - which requires running the engine to operate but - if you're going to have to start the engine it does seem you could just then turn on the van's built-in A/C.

The 2nd alternator is usually a high-ampere output unit.

It is particularly useful when paired with a lithium battery, because lithium battery can accept a much higher charging ampere than lead-acid type.

If you use the chassis alternator, it will take ages to charge up your battery.

[DCHitt]

In keeping with the "Keep it simple" idea. Get a van with a gas engine and use that engine to do the heavy lifting directly, like heating and cooling.

The trend seems to be to do everything with electric and that leads to big batteries, big generators, etc.

[markopolo]

There's that option. Booster has mentioned it before but no one continued that discussion iirc. If cooling, the engine and exhaust system throw off heat. The fiberglass floor in the '04 RT I had would get noticeably warm from heat radiating off the exhaust system. My guess is there would be net positive cooling but it's worth checking to see in the rear inside gets cooler.

When idling, the current setup in my van would likely be able to run both the dash air and probably up to an 8,000 BTU air conditioner simultaneously with the system voltage remaining high enough that all the power would come from the single stock 124A alternator. I know for sure that it can do that with a 5,200 BTU A/C. I think I could get around 4 hours or so of a/c compressor time on batteries alone with the 5,200 BTU A/C and close to 400AH battery capacity without taking the batteries down too low.

The first half hour of cooling could be both dash air and rear air for max cooling but still leaving the batteries at full capacity.

A standard older Class B would need:
- upgraded wiring and fusing from alternator to house batteries (equivalent to 1 gauge in my van - some stock vans might only have 6 gauge)
- upgrade from isolator to relay type separator to avoid voltage drop
- added batteries for greater capacity - 400AH or so
- something like a 2000W PSW inverter preferably with automatic transfer switch
- possibly a higher output alternator
- maybe a way to increase idle rpm

I don't really see this as a use-all-the-time solution as I don't know what the long term effect on the alternator would be. I see it as being more for those odd occasions when no other option is practical.

[DCHitt]

Originally Posted by markopolo

When idling, the current setup in my van would likely be able to run both the dash air and probably up to an 8,000 BTU air conditioner simultaneously with the system voltage remaining high enough that all the power would come from the single stock 124A alternator. I know for sure that it can do that with a 5,200 BTU A/C. I think I could get around 4 hours or so of a/c compressor time on batteries alone with the 5,200 BTU A/C and close to 400AH battery capacity without taking the batteries down too low.

The first half hour of cooling could be both dash air and rear air for max cooling but still leaving the batteries at full capacity.

A standard older Class B would need:
- upgraded wiring and fusing from alternator to house batteries (equivalent to 1 gauge in my van - some stock vans might only have 6 gauge)
- upgrade from isolator to relay type separator to avoid voltage drop
- added batteries for greater capacity - 400AH or so
- something like a 2000W PSW inverter preferably with automatic transfer switch
- possibly a higher output alternator
- maybe a way to increase idle rpm

Mine is still a lot simpler by using the manufactures "rear heat/ac" package and installing an aftermarket evaporator/radiator. No need for the roof AC unless plugged in. Also a lot quieter.

[markopolo]

It would be interesting to see some temperature & time data from your setup. It sounds like a good idea. Do you think it would be a retrofit option in an already finished B van?

The 5,200 BTU rear air in my van can easily cool the rear (like 72F) but not so much the cab area (like 88F). Part of the fault is due to the compartmentalized layout.

[DCHitt]

Originally Posted by markopolo

It would be interesting to see some temperature & time data from your setup. It sounds like a good idea. Do you think it would be a retrofit option in an already finished B van?

The factory rear AC option taps into the dash AC lines. I guess it can be done on a finished B van but you would need some AC skills. Mine came with the taps already there. I did add a thermostat to the rear fan so I didn't have to get up and adjust the dash controls while I'm sleeping.

Sorry I don't have a lot of data. It is simple and seems to work without a big battery, generator, etc. to fool with. I'm still looking forward to figuring out how to "AutoStart" the engine. Maybe a Can Buss hack.

[dlj@salinas.ent]

I have a 2016 Roadtrek Sprinter 3500. It has no built-in generator which look very expensive to have installed. I own at Honda 2000i, and would like to pair it properly to another Honda generator with a 30 amp outlet. There are several Honda models for this purpose. Any recommendations on which one?

[rowiebowie]

Originally Posted by dlj@salinas.ent

I have a 2016 Roadtrek Sprinter 3500. It has no built-in generator which look very expensive to have installed. I own at Honda 2000i, and would like to pair it properly to another Honda generator with a 30 amp outlet. There are several Honda models for this purpose. Any recommendations on which one?

Welcome to the forum!

I believe you'll want to pair it with another Honda 2000i so that they pair without problems. Some on this forum report the ability to run their a/c off of only one Honda 2000i by installing an "Easy Start" kit on their roof air conditioner. Also, Honda now makes a 2200i with a bit more power in the same size and weight.

[gerrym51]

Originally Posted by dlj@salinas.ent

I have a 2016 Roadtrek Sprinter 3500. It has no built-in generator which look very expensive to have installed. I own at Honda 2000i, and would like to pair it properly to another Honda generator with a 30 amp outlet. There are several Honda models for this purpose. Any recommendations on which one?

what model do you have? Does it have the 'underhood generator;

[rowiebowie]

Originally Posted by rowiebowie

Welcome to the forum!

I believe you'll want to pair it with another Honda 2000i so that they pair without problems. Some on this forum report the ability to run their a/c off of only one Honda 2000i by installing an "Easy Start" kit on their roof air conditioner. Also, Honda now makes a 2200i with a bit more power in the same size and weight.

Here's a quote from Micro Air, makers of the Easy Start that was posted today on Airforums. It refers to the Honda 2200i.

Originally Posted by mattRox

From Micro-Air

"Hello Matt,

Typical running currents for 15kbtu A/C units is in the neighborhood of 14-16 amps, varying with manufactures and speaks to the poster’s issue. Adding any loads will definitely come close to popping 15A breakers. For your Honda, we’ve measuring in house that they can give you their peak rating for extended periods of time and as such recommend them whenever possible. 2200 watts translates to ~18 amps of headroom (at sea level!) and is plenty to simply run a normally operating A/C unit.

Best,
Nick", Micro-Air