Stark Batteries finally in my Travato

[wincrasher]

Got my project done, at long last!

Wincrasher's Travels: Stark Power Lithium Battery Upgrade for the Travato

[markopolo]

Nice article - I like your writing style.

We need more reports from RV'ers like you and some long term usage data on these drop-in lifepo4 batteries. The weight savings would be really good in a small boat or on a trailer tongue.

[tgregg]

I read your article also and agree it's well written, but I have two questions.

How did you calculate the 225 AH useable capacity and what are you referring to when you said " it uses 725 and 4.5 amps" while describing the existing PD9245C smart charger / converter?

Thanks for writing about your purchases, upgrades and modifications.

[wincrasher]

Originally Posted by tgregg

I read your article also and agree it's well written, but I have two questions.

How did you calculate the 225 AH useable capacity and what are you referring to when you said " it uses 725 and 4.5 amps" while describing the existing PD9245C smart charger / converter?

Thanks for writing about your purchases, upgrades and modifications.

Good questions.

I calculate the usable capacity like this: 2 Batteries @ 125 ah each = 250 ah hours total. 90% allowable depth of discharge x 250 ah = 225 ah.

For the AGMs, use the same equation, but change the 90% to 50%, and the 125 to 110. Some may disagree with my assertion that 90% is safe, but they'd be wrong.

The charger/converter, at max output, uses 725 watts and 4.5 amps AC (110v). In theoretical terms, it puts out a max of 45 amps DC, but in practical terms, it's somewhere in the mid to high 30's.

[gregmchugh]

And some people would use 80% discharge on their AGM batteries and get 176 amp hours and they would not be wrong to do so any more than you are not wrong to use 90% discharge on your lithium batteries...

Not sure there are right and wrong choices, simply trade offs of cost vs benefits, with some people making choices based on more valid info than others. The lifetime cost savings of AGM discharge to 50% vs 80% is likely not much if you only care about battery capacity but lithiums, of course, have other advantages for the higher cost.

[booster]

Originally Posted by gregmchugh

And some people would use 80% discharge on their AGM batteries and get 176 amp hours and they would not be wrong to do so any more than you are not wrong to use 90% discharge on your lithium batteries...

Not sure there are right and wrong choices, simply trade offs of cost vs benefits, with some people making choices based on more valid info than others. The lifetime cost savings of AGM discharge to 50% vs 80% is likely not much if you only care about battery capacity but lithiums, of course, have other advantages for the higher cost.

I agree, totally. We just had a discussion in another thread about the DOD on lead acid batteries that seemed to totally blow up the 50% is best theory. Boiled down to the total AH used over the life of the battery was almost identical, no matter how deep or shallow you went, within reason.

I think more folks would have issue with the going to 100% full and having a non cutoff charger, than would have issue with the 90% discharge.

[GigaGeek]

Wincrasher,

I've been wondering when you're going to drop your Onan generator out from under your coach and install an underwood generator. Add a few more of those Stark batteries underneath to replace that noisy genny and you'll have a WinneTrek.

Any thoughts of that?

[wincrasher]

Actually, I'm one of the few folks that like my Onan.

In some of my testing on alternator charging, I had alot of anxiety about leaving the van engine idling for an extended period. Also I question the wisdom of putting hundreds of hours of idling time on a fairly expensive engine, when a stand-alone generator is pretty cheap in comparison - with care you should get several thousand hours out of it. When it blows up, you can get a new one plugged in for around $2800-3000.

That said, the costs and complications of doing an "underhood" generator are significant. The kit, new cabling, inverter, relays, etc. Not convinced it's really worth it for the benefit of "silence".

95% of my generator use is for air conditioning for the dog while I'm either in restaurants or shopping. So how much noise it makes is really not a concern for me.

Over this last weekend (3 days), my batteries held steady at 13.4 volts with the refrigerator and ventilator running. The solar easily kept ahead of my loads during the days and charged up what was depleted overnight. So for my normal usages, two of these batteries may be fully adequate for quite a long period of "off-grid".

What I would really like is more propane capacity. But there is hope - someone mentioned on the facebook group that you can add a propane bottle to your bbq connector and backfeed the house LP system. You need to engage the shutoff switch to make that work.

[gregmchugh]

There are several kits that allow you to connect a standard refillable propane tank to your RV as needed to supplement your propane tank. Here is one example that also includes an outlet for a propane appliance...

http://www.amazon.com/gp/product/B00...G8SA69B89MN8ZV

[wincrasher]

Originally Posted by gregmchugh

There are several kits that allow you to connect a standard refillable propane tank to your RV as needed to supplement your propane tank. Here is one example that also includes an outlet for a propane appliance...

Amazon.com: Camco 59123 Propane Brass Tee with 4 Port with 5' and 12' Hose: Automotive

That's not going to let you go from a 20lb bottle to your existing lp quick-connect. That kind of hose is elusive in my searching amazon.

[booster]

Originally Posted by wincrasher

Over this last weekend (3 days), my batteries held steady at 13.4 volts with the refrigerator and ventilator running. The solar easily kept ahead of my loads during the days and charged up what was depleted overnight. So for my normal usages, two of these batteries may be fully adequate for quite a long period of "off-grid".

What I would really like is more propane capacity. But there is hope - someone mentioned on the facebook group that you can add a propane bottle to your bbq connector and backfeed the house LP system. You need to engage the shutoff switch to make that work.

The solar results are similar to what we saw on our final trip on the old system. 300 watts solar, 260ah of wet cells. If we had decent sun we easily recovered the daily use, even in the middle of September in Utah, so long periods are possible if the sun is good. We would need good sun probably 50% of the time to go long term. I think you have two 80 watt and a 120 watt portable? so similar size and with compressor frig. We look at the engine generator as fall back position, not as the primary charging. With non lithium batteries, there is also a faster charge rate to 85% so we get a bit more time in absorption to top off with the solar, but it is not huge.

What do you use the propane for that you need more capacity? We do heat, and the grill, never use the stove, and it usually only needs filling once a year.

[wincrasher]

I have a 100 and two 80's on top. I have a 120 portable if I want to carry it (which I don't).

The propane powers the Truma (heating & hot water) and the cooktop. Yes, the fridge is compressor. The Truma will run on 110v if you have it.

I've found with the Truma, for just hot water and cooking, I can go for weeks on my little propane tank (6 gallons). It's the cabin heating which gobbles it up. Still MUCH more efficient than a standard furnace, but if you have cold temps, you'd probably need to refuel in 3 or 4 days. An auxiliary bottle would give you some more flexibility if it was really cold.

I suppose if you didn't have propane available, you could always run the generator and run the Truma on 110v. Not desireable, but it would work if you were in a bind on propane.

[Davydd]

It is the large battery bank and inverter that is key coupled with the dual alternator. Then you never idle your engine for those short times you might leave your dog in the B. Since the alternator charges batteries about twice as fast as an Onan generator you don't idle your engine to charge. You simply charge by driving be it while on the highway or the many incidental times when staying longer at a campground like driving up to a trailhead, sight seeing, store, etc.

Benefit of silence? That is a minor part of it. How about...

Less weight.
Less space taken up that can be used for other purposes.
Less cost.
Less maintenance as in no second combustion engine.
No "exercising".
More versatile charging opportunities as mentioned above.
Stealth charging. A generator is obvious but everyone has to run their engines even in a no generator campground. Yeah this is sneaky and I have never done it.
Faster charging.
Auto start for charging and low battery protection is more straightforward and is standard with those converters building dual alternators.
No added fuel use other than a minor hit on MPG.
Potential to eliminate propane with a diesel B (which I have done.)

The silence? A diesel engine isn't that much quieter outside but when you are inside your B it is vastly much quieter than an Onan generator right below a bed.

I made my prediction on another board already. The Onan generator will be history in less than 5 years in a Class B sold by most all converters. The dual alternator will be the standard.

[gregmchugh]

Originally Posted by wincrasher

That's not going to let you go from a 20lb bottle to your existing lp quick-connect. That kind of hose is elusive in my searching amazon.

If the Travato has a low pressure quick connect then you need to do something like this with a regulator on the portable bottle...

RV.Net Open Roads Forum: RV Lifestyle: Extend-A-Stay propane adapter kit

[casd]

I have a Roadtrek Agile , I have 2 160 watt Grape solar on roof , special aluminum rack custom built, I get about 25 amps out of it lets say 5 good hours a day, not enough, I have same issue about 2nd alternator but might have the original Mercedes 2nd installed

Seeing I have a 16 gallon propane tank has anybody installed 2 Honda 2000 generators underneath or a 3000 with electric start and converted to propane ? seems to me this would be a inexpensive risk to idling your expensive diesel they tell you not to idle , but driving down the road makes sense to have the 2nd alternator

Originally Posted by Davydd

It is the large battery bank and inverter that is key coupled with the dual alternator. Then you never idle your engine for those short times you might leave your dog in the B. Since the alternator charges batteries about twice as fast as an Onan generator you don't idle your engine to charge. You simply charge by driving be it while on the highway or the many incidental times when staying longer at a campground like driving up to a trailhead, sight seeing, store, etc.

Benefit of silence? That is a minor part of it. How about...

Less weight.
Less space taken up that can be used for other purposes.
Less cost.
Less maintenance as in no second combustion engine.
No "exercising".
More versatile charging opportunities as mentioned above.
Stealth charging. A generator is obvious but everyone has to run their engines even in a no generator campground. Yeah this is sneaky and I have never done it.
Faster charging.
Auto start for charging and low battery protection is more straightforward and is standard with those converters building dual alternators.
No added fuel use other than a minor hit on MPG.
Potential to eliminate propane with a diesel B (which I have done.)

The silence? A diesel engine isn't that much quieter outside but when you are inside your B it is vastly much quieter than an Onan generator right below a bed.

I made my prediction on another board already. The Onan generator will be history in less than 5 years in a Class B sold by most all converters. The dual alternator will be the standard.

[booster]

Originally Posted by casd

I have a Roadtrek Agile , I have 2 160 watt Grape solar on roof , special aluminum rack custom built, I get about 25 amps out of it lets say 5 good hours a day, not enough, I have same issue about 2nd alternator but might have the original Mercedes 2nd installed

Seeing I have a 16 gallon propane tank has anybody installed 2 Honda 2000 generators underneath or a 3000 with electric start and converted to propane ? seems to me this would be a inexpensive risk to idling your expensive diesel they tell you not to idle , but driving down the road makes sense to have the 2nd alternator

You can get 125 amp hours a day (25 amps times 5 hours), and that is not enough? That also ounds very high for 320 watts of flat placed solar. Does you controller have a resettable totalizer that you can set each day to see how many amp hours the solar puts out? That is the best way, I think, to tell what is going on. A battery meter like a Trimetric only shows what is going into the batteries and won't show total solar output which can have a lot going to loads. On very good days, we have seen a touch over 90 amp hours a day with our 300 watts of Grape solar.

There has been a lot of talk about mounting Hondas underneath, but as far as I know, it hasn't really been done. Height of the Hondas appears to be a big issue.

[gregmchugh]

Originally Posted by casd

I have a Roadtrek Agile , I have 2 160 watt Grape solar on roof , special aluminum rack custom built, I get about 25 amps out of it lets say 5 good hours a day, not enough, I have same issue about 2nd alternator but might have the original Mercedes 2nd installed

Seeing I have a 16 gallon propane tank has anybody installed 2 Honda 2000 generators underneath or a 3000 with electric start and converted to propane ? seems to me this would be a inexpensive risk to idling your expensive diesel they tell you not to idle , but driving down the road makes sense to have the 2nd alternator

Do you have the standard two 6 volt AGM batteries or something other than that?

What is your goal for adding the propane fueled generator(s)?

If you simply want to get your AGM batteries fully charged every day when you are in place and not driving, how many amp hours do you use in a day?

I reinforce the idea that you should understand your specific energy usage profile and your goals in order to decide what upgrades make sense.

[Davydd]

Originally Posted by casd

I have a Roadtrek Agile , I have 2 160 watt Grape solar on roof , special aluminum rack custom built, I get about 25 amps out of it lets say 5 good hours a day, not enough, I have same issue about 2nd alternator but might have the original Mercedes 2nd installed

Seeing I have a 16 gallon propane tank has anybody installed 2 Honda 2000 generators underneath or a 3000 with electric start and converted to propane ? seems to me this would be a inexpensive risk to idling your expensive diesel they tell you not to idle , but driving down the road makes sense to have the 2nd alternator

As I mentioned, I have a large battery bank and inverter. 800ah lithium ion and 2800 watt Outback inverter/charger. I have no propane and that is another weight and space savings. I also have 420 watts of solar but it is an insignificant contributor when the bulk of my travel time is fall/winter/spring and having the second alternator.

Idling a Sprinter diesel is not a problem and the issue is overblown. I also mentioned it is a feature I seldom used considering 209 nights on the road I checked my total idling run time and it was 8 hrs. 40 min. Much of that was demonstrating, testing and experimenting. Once I start it, I tend to just let it run a while like once to see if it would run the maximum time it was set to run (1 hr. 50 min) or just to let it go ahead and top off the batteries. Last year I spent a lot of time testing and experimenting to understand what was going on.

Solar, IMO, is more important for a small battery bank simply because it provides a higher percentage of battery recharging. My flat on the roof solar on a good day basically can replenish what my 12v compressor refrigerator uses. 20 minutes of driving or idling can do that and I am incapable by habit of sitting parked much more than three days so never run down my battery. Then most of the time I spend that much time in one place it is at Class B rallies and socials and those always by consensus are held at campgrounds with shore power.

If I could do solar again, I envision less panel but the ability to angle it and track the sun. Something like a crank up Winegard TV antenna that could be raised to the sun angle and then turned to track the sun so you are not directional parking dependent. In Death Valley in February I saw more portable solar panels than anywhere else by I assume the California veterans of the park but I would not want to carry one in a space precious Class B for the benefit gained.

I can't speak to the use of Honda generators. That is beyond my expertise.

[gregmchugh]

If you still have AGM batteries the big advantage solar provides is significantly reducing the time needed for generator charging when you are in place and not driving. In order to fully charge the AGM batteries run whatever generator you are using early in the day to handle the majority of the high charge amp bulk phase and then let the solar handle the rest of the rest of the bulk and absorption phases. A good understanding of your amp hour usage profile will let you know how long to run the generator and get the full charge completed by rather solar. Running a generator to handle the lower current long time period absorption phase is not the way to go unless you do it while driving using an engine generator.

[wincrasher]

I'm starting to think about how I may keep these batteries warm in the winter months. I'm not really much of a winter traveler, but it may be a good project to do.

Some input on how to do this would be good.

My initial thoughts were to remove the batteries from their brackets, apply a heating pad and a thermal sensor, then some insulation material and then return them to their brackets. The plus to doing it this way is that you have the insulation protected by the metal brackets. The downside is that it might be a tight fit.

But in looking at this picture, why not build a box to slip over the brackets? It would leave a little air space around the batteries. Maybe a box made from foam board encased in poly? I'd still use a heating pad for each battery. Maybe a switch that could be tuned to come on below 32 and turn off at 35 or 40?