Winnebago Travato thread here

[wincrasher]

With the current two battery AGM setup, you are not going to run much of anything for very long. I'd like to know how long they can run the air conditioner with only 100 amp hours of useable capacity.

Most likely you are looking at probably 15 minutes of a coffee pot or a hair dryer + about the same in the microwave and then you'd be done.

Switching to lithium would nearly double that capacity, and the useable time for the appliances.

[thefitrv]

Glad you're finding the site useful! (and entertaining)
Since I was going to be working with currents approaching 150 amps, and since it would have been my first inverter install, I decided to take the safe route, and had it installed by the good folks at AM Solar.
While they were at it, we also installed a Magnum Battery Monitor, which is something like a Trimetric.
Wasn't cheap though.

[thefitrv]

Originally Posted by wincrasher

With the current two battery AGM setup, you are not going to run much of anything for very long. I'd like to know how long they can run the air conditioner with only 100 amp hours of useable capacity.

Most likely you are looking at probably 15 minutes of a coffee pot or a hair dryer + about the same in the microwave and then you'd be done.

Switching to lithium would nearly double that capacity, and the useable time for the appliances.

We can run the microwave long enough to do whatever we need to do with the microwave. We can run the hair dryer long enough for me , but Stef hasn't tried it yet. The voltage sag when running the big loads triggers the cut-off before we actually get the battery capacity too low.

A/B tests with AGM vs. lithium batteries are on my list.

[BobB]

Originally Posted by thefitrv

A/B tests with AGM vs. lithium batteries are on my list.

I am sure there are many readers on this forum who would love to see that (and put in their 2 cents worth). Just reading the discussion on the recent Roadtrek E-Trek Battery Replacement thread, in addition to just trying to help one reader, there was a lot of back and forth just figuring how to set up and monitor that system, 12v vs 24v, charging/discharging rates, etc., etc. A bit/a lot over my head, but very interesting.

[ghosting]

Thanks for all that info. I'm still trying to figure out all the sources of power inputs and outputs, and what are most likely to be the limiting factors for boon-docking. I've thought about charting it out so that I an start to get my head around it. I'm a little slow.

Luckily, no one in my home uses a hair drier, so we don't need to worry about that, and most of our electrical devices can run of 12v. I can see the utility of running the microwave and AC without the generator, but I was wondering about the battery capacity... so thanks again for all that info.

[BobB]

Originally Posted by ghosting

Thanks for all that info. I'm still trying to figure out all the sources of power inputs and outputs, and what are most likely to be the limiting factors for boon-docking. I've thought about charting it out so that I an start to get my head around it. I'm a little slow.

Sounds like an energy audit. There are a number of spreadsheets out there in books or online. You fill in the item - appliance, light, etc. - how many watts/amps it uses and how many hours per day you will use it. Add energy inputs like generator use and solar, and then info on the battery system discharge rates (AGM vs Lithium vs ??), how long you want to run without hooking in 110v, etc.

Will give you a good idea on how big a battery bank you need and if in Excel or similar, you can easily play "what if".

Just be careful keeping your volts - amps - watts straight. You also need to know how much each item uses in energy; there are lists out there or look each item up on the manufacturers website.

And you can always post it on this forum to get review.

[Scottbaldassari]

Originally Posted by thefitrv

...We can run the hair dryer long enough for me ,

yeah, that's good.

Originally Posted by thefitrv

...The voltage sag when running the big loads triggers the cut-off before we actually get the battery capacity too low...

So, there IS a low battery cut off? I was reading elsewhere (on FB TOG I think) about someone who said they drained (and ruined) their batteries... I found it surprising that there was no battery "shut off" once the batteries dropped to a certain voltage..

[wincrasher]

There is no low battery cutoff from WGO unless it is part of their inverter setup (aftermarket installed by AMSolar), which I suspect is what James is talking about.

You can easily add such protection by installing an EC-30w remote for your Onan. It will kick on the generator to recharge batteries at whatever low voltage you set.

[thefitrv]

Originally Posted by wincrasher

There is no low battery cutoff from WGO unless it is part of their inverter setup (aftermarket installed by AMSolar), which I suspect is what James is talking about.

Correct. The low battery cut-off determines when the inverter stops inverting. It protects the batteries from being too deeply discharged by the inverter. On the Magnum inverter, you can set this. Still working out what the correct voltage might be. But it only affects the inverter, regular 12v functions remain working.

Interesting fact: With the vehicle running, and the inverter on, I can run the microwave, and I'm still putting current into the batteries... Just don't tell Roadtrek. They're mad enough at me already. lol.

[Vardo]

In regard to why you would want to use an inverter, I am a fan of toast or bagels at breakfast, so I run a small toaster off the inverter regularly (stove-top toasters are a last resort). Also, I occasionally take a coffee-maker when my van is the "food truck" on group trips. These in addition to the occasional food or drink warm-up in the microwave. Total use of all these appliances would be less than 10 minutes at a time combined in my usage, and I find that with my 100w solar panel the batteries generally show a full charge again within an hour or two on a sunny day even if I am not driving to recharge them. My personal preference is to not use the generator in a campground if possible and the inverter and solar combination enables this pretty well.

[Scottbaldassari]

Originally Posted by wincrasher

There is no low battery cutoff from WGO unless it is part of their inverter setup (aftermarket installed by AMSolar), which I suspect is what James is talking about.

You can easily add such protection by installing an EC-30w remote for your Onan. It will kick on the generator to recharge batteries at whatever low voltage you set.

Ahh. Thank you. Makes sense.
And that remote definitely sounds like a "should have" item.

Originally Posted by fitrv

Interesting fact: With the vehicle running, and the inverter on, I can run the microwave, and I'm still putting current into the batteries... Just don't tell Roadtrek. They're mad enough at me already. lol.

Are you telling me you have developed an advanced technology underhood generator for the Travato?
I guess that would be an "E-vato"??

[markopolo]

Originally Posted by thefitrv

......................
Interesting fact: With the vehicle running, and the inverter on, I can run the microwave, and I'm still putting current into the batteries... Just don't tell Roadtrek. They're mad enough at me already. lol.

I've been hoping for someone with one of the Promaster vans to try that and post the result.

Wincrasher previously reported finding 1 gauge wire leading to the coach battery on his previous Travato so that part is ready for the job.

Simply put, if you have an inverter installed then you have "engine generator". The wiring, fusing and size of the inverter determine how much power will be available to the coach.

The RT I had a decade ago had only 6 gauge wire on that run. It came with a 600W inverter and there were 50 amp breakers in that circuit so I had a 600W engine generator. Booster's RT is 3 years newer and originally came with 4 gauge, 750 watt inverter and 80 amp breakers.

In my GMC van, the previous setup (finished some upgrades yesterday) maintained 13.9 volts while using the microwave oven and with the engine running - http://www.classbforum.com/forums/f5...html#post27183 . That was with the stock 124 amp alternator, cheap ($120) 1000w psw inverter, $70 charge relay & $50 Xantrex automatic transfer switch for ease of use. You don't have to spend a lot for the convenience.

Winnebago could easily start adding an inverter/charger to their units - instant engine generator.

Just a quick note re: Promaster diesels as I see more mention of them on this forum recently. The diesel supplement to the owner manual warns against prolonged idling:

http://www.ramtrucks.com/download/pd...sel-SU-1st.pdf

Page 38

Engine Idling
Avoid prolonged idling, long periods of idling may be harmful to your engine because combustion chamber temperatures can drop so low that the fuel may not burn completely. Incomplete combustion allows carbon and varnish to form on piston rings, cylinder head valves, and injector nozzles. Also, the unburned fuel can enter the crankcase, diluting the oil and causing rapid wear to the engine.

[wincrasher]

Originally Posted by thefitrv

Correct. The low battery cut-off determines when the inverter stops inverting. It protects the batteries from being too deeply discharged by the inverter. On the Magnum inverter, you can set this. Still working out what the correct voltage might be. But it only affects the inverter, regular 12v functions remain working.

Interesting fact: With the vehicle running, and the inverter on, I can run the microwave, and I'm still putting current into the batteries... Just don't tell Roadtrek. They're mad enough at me already. lol.

Not surprising. The AGM batteries I think are limited to accepting 50 amps by what we've gleaned from the wiring diagrams.

If you make the switch to lithium, you may find that, since they can take up to 100 amps each, you may have issues running the inverter with the engine running if the batteries are severely depleted. But that's just a guess. I found that a single lithium battery would not get even 50 amps from the alternator, let alone the 100 amp it should be able to draw.

[thefitrv]

Well, honestly, I still intend to use the "real" generator for any extended use. After all, the primary use case for the Onan is to run for long periods while sitting still - unlike the vehicle engine. But interesting that the gas engine would be more trouble-free than the diesel in that regard.

I also had them add a cut-off switch so that I can disconnect the alternator and prevent it from charging the batteries altogether. Did this in anticipation of having lithium batteries some day and don't want to charge them while it's freezing outside. (Added a second switch to prevent solar charging too.)

[wincrasher]

Great idea on those switches. Manual control of the battery charging (and protection) is probably good enough for many of us. You should write up the details on your inverter charger install. The Magnum is a great unit.

[BobB]

Originally Posted by thefitrv

I also had them add a cut-off switch so that I can disconnect the alternator and prevent it from charging the batteries altogether. Did this in anticipation of having lithium batteries some day and don't want to charge them while it's freezing outside. (Added a second switch to prevent solar charging too.)

James - when you are done - for this season how about an updated electrical schematic of all of these improvements/changes (+ the magnum install Wincrasher mentioned) ? Could be a winter project?

[ghosting]

Originally Posted by BobB

James - when you are done - for this season how about an updated electrical schematic of all of these improvements/changes (+ the magnum install Wincrasher mentioned) ? Could be a winter project?

Yes please!

[number82]

I'm thinking of buying a Travato (gas) in the spring and would like to tow a trailer loaded with two motorcycles. The total weight of the trailer and contents would be around 2000lbs... which I believe to be the maximum recommended for this vehicle. The plan would be to tow the motorcycles out west from Ohio (around 4k miles RT)

Does anyone have any experience or thoughts on towing with the ProMaster? (i.e.. is this a poor idea?)

[bobojay]

Number82, go check out the ram promaster forum and ask over there. Lots of info over there. Ram Promaster Forum

You definitely want to watch your tongue weight. The factory hitch is not the best setup.
Also be aware if you are at all thinking about it, the diesel option is being discontinued in the WGO Promasters....

[wincrasher]

Where did you hear that WGO is discontinuing the PM diesel?