UHG - why a separate alternator?

[kite_rider]

I've been enjoying this thread and I really like the direction it's taking regarding the types of loads on the charging system with respect to Lithium and AGM batteries.

Let me step back and preface that my campervan goal is to have the convivence of system like Davydd's, but on a Joe 6-pack budget!

Booster, I have a similar power requirements to the ones you've highlighted above and I'd like to be able to camp up to 2-3 days with marginal solar (I have 200W on the roof) and not having to run the engine to charge the battery. Most of the time I use the van every day so it's rare that I ever need 2-3 days. Also, my heaviest electrical use seems to happen when I'm out backcountry skiing and in that situation my solar contribution is minimal (short days with frequent snow on the panels).

I know there are Lithium skeptics amongst us, but I'm starting to think a hybrid Lithium-AGM solution is really the way to go. I say this because on a typical day the Lithium battery maintains both my cabin 105Ah AGM and my chassis 105Ah AGM batteries at a 'float' level. So the only alternator load is the Lithium battery and that is less load than a low SOC 400Ah AGM bank would draw. Maybe even less than 400Ah AGM bank would draw at 50% SOC? In the very rare event that I would draw the system into the sub 50% SOC range of my AGM battery my Lithium battery would disconnect from the system (currently at 12.5V, but I can set it to anything) and then it would not come back on until the charging voltage is a steady 13.7V - again easily changeable to another voltage if desired. So this setup prevents all of the batteries demanding full power from the alternator at the same time.

The 105Ah AGM came with the pre-built van. I built the Lithium battery with cells purchased on E*Bay and a BMS cobbled together from Amazon.com for a total cost of less than $800. I've bench tested this Lithium battery from a starting point of 90% SOC down to 20% SOC and measured over 180Ah of usable power storage @ a 10A rate. I also bench tested my AGM battery (a brand new one provided on warranty) and only got about 42Ah (100%SOC to 50% SOC @ 10A rate). So in my way of thinking, it would take 4 of these 105Ah AGM batteries to provide a similar amount of usable energy (let's not debate if only using 50% SOC is too conservative for the moment). The AGM batteries cost $291 retail so they are more expensive than the Lithium option by a lot. Not to mention the added space and weight required. Then we have the issue of creating too much load on the single alternator with 400Ah of AGM.

I'm not saying my system is going to be 'worry free' forever. I'm doing something unique and I expect that stuff will happen. But the more I look into large battery banks, UHG, and complex B-B management systems the happier I am with my very simple setup.

[booster]

There is quite a lot of information on a couple of hybrid systems on the forum. They seem to work well, and I think the biggest question is the need or not of a B to B charger so you can charge the lithium quickly and then let it charge the AGM, then recharge the lithium if you want to. This shortens actual charge time a lot, it appears.

[michaelingp]

Originally Posted by Davydd

I don't know about how the Dodge-Ram split works out. But if a Dodge dealer is not selling RAM Promasters you might not get service or satisfactory service.

This is definitely true. One of the reasons I went with Promaster over MB was the idea that it would be easier to get service. I'm not sure if it turned out to be a good reason. Where I live, only the big RAM truck dealer will service Promaster, and when I needed service in Seattle, I couldn't find any local RAM dealer who would service a Promaster (had nothing to do with the conversion).

[B Eventually]

Originally Posted by michaelingp

This is definitely true. One of the reasons I went with Promaster over MB was the idea that it would be easier to get service. I'm not sure if it turned out to be a good reason. Where I live, only the big RAM truck dealer will service Promaster, and when I needed service in Seattle, I couldn't find any local RAM dealer who would service a Promaster (had nothing to do with the conversion).

Very interesting. I live west of Seattle and I have to drive or have the rv towed to Tacoma for service. Last fall we experienced the later first hand when Winnebago’s wiring worked lose in the engine compartment. It caused Hill Holder engine errors necessitating a tow. The dealer took three attempts to discover the actual problem too.

When the kids are grown, I think I’ll go the self build route with a Transit. Hopefully by then Ford will have designed a second alternator mount like the Sprniter has.

[Winston]

Originally Posted by kite_rider

. . . where folks talk about coolant leaks related with UHG and I think there is a pattern emerging for the Promaster vans related to 2nd alternator installations and it's not a good pattern.

Originally Posted by booster

The failure of peripheral equipment like the hoses is very specific and essentially 100% preventable both initially or after it is fixed.

This photo depicts a not too uncommon 'pose' we adopted the first year of operations. But we think Booster is correct . . . forewarned, we believe it is possible to install the Nations 2nd alternator on a Promaster without further incident.

[InterBlog]

Originally Posted by kite_rider

I was looking for links related the 'blown alternator(s)' on the FitRV Promaster mentioned in a previous post...

Quite by accident, I found a reference I had screengrabbed in general relation to failing alternators.

I'm assuming that it's on a flatbed in this pic because it NEEDED to be on a flatbed - because something went wrong with that alternator that is called out.

Of course, now that I re-read it, James's wording leaves it a bit open to interpretation. I never did research what exactly happened there.

[B Eventually]

Originally Posted by InterBlog

Quite by accident, I found a reference I had screengrabbed in general relation to failing alternators.

I'm assuming that it's on a flatbed in this pic because it NEEDED to be on a flatbed - because something went wrong with that alternator that is called out.

Of course, now that I re-read it, James's wording leaves it a bit open to interpretation. I never did research what exactly happened there.

IIRC, that's when Lance was towed after their secondary/optional alternator's belt cut through a cooling hose.

I follow their blog and I'm almost 100% certain they've never needed to replace the alternator they use for charging their batteries.

[booster]

Originally Posted by B Eventually

IIRC, that's when Lance was towed after their secondary/optional alternator's belt cut through a cooling hose.

I follow their blog and I'm almost 100% certain they've never needed to replace the alternator they use for charging their batteries.

I agree, IIRC this was when the now referred back to overheating occurred.

[avanti]

A large percentage of these "UHG disaster" stories seem to allude to coolant system failures. I don't know whether they can all be traced back to this one alleged incident, or whether it is a common issue.

I do have to say, though, that either way, such a failure mode almost certainly represents gross incompetence on the part of the installer.

[B Eventually]

Originally Posted by avanti

A large percentage of these "UHG disaster" stories seem to allude to coolant system failures. I don't know whether they can all be traced back to this one alleged incident, or whether it is a common issue.

I do have to say, though, that either way, such a failure mode almost certainly represents gross incompetence on the part of the installer.

I wouldn't disagree, but people are installing these secondary alternators into an tight engine compartment that was not designed to support an additional alternator.

Hearing all of these promaster UHG issues is helping me feel a little less bad to be stuck with an Onan.

Does anyone care to speculate on the ability to drive a Promaster with a broken stock alternator via Winnebago's battery boost switch? In our case, we could even fire up the Onan to keep the RV + chassis battery topped off.

[booster]

Originally Posted by avanti

A large percentage of these "UHG disaster" stories seem to allude to coolant system failures. I don't know whether they can all be traced back to this one alleged incident, or whether it is a common issue.

I do have to say, though, that either way, such a failure mode almost certainly represents gross incompetence on the part of the installer.

The problems because of installation was mentioned earlier, also, and it is a bit of an odd thing that there are so many, it appears from the stories anyway.


The only thing I can think of is that the installers may not be allowing for engine rocking, which in front drives can be a lot bigger than in the rear drives, at least from what I have seen. Being a very heavy van would also make it torque over more and more often because of the power needed to move the 9000#.

[avanti]

Credit to Mercedes for engineering a location and bracket for installing a power takeoff (alternator, second compressor, hydraulic pump, etc) for the Sprinter engine. On the V6 it requires rerouting some coolant lines, although there is a proper design for doing so. On the I4, it is straight bolt-on.

[gregmchugh]

Originally Posted by avanti

A large percentage of these "UHG disaster" stories seem to allude to coolant system failures. I don't know whether they can all be traced back to this one alleged incident, or whether it is a common issue.

I do have to say, though, that either way, such a failure mode almost certainly represents gross incompetence on the part of the installer.

EHGNA had the coolant hose damage issue also with their intitial installations, the hoses needed to be rerouted as I recall for the aux alternator install and something happened after the install to get the hoses damaged. Happened many times before they found out and got a fix in place.

[kite_rider]

Originally Posted by Winston

This photo depicts a not too uncommon 'pose' we adopted the first year of operations. But we think Booster is correct . . . forewarned, we believe it is possible to install the Nations 2nd alternator on a Promaster without further incident.

Ha! I'm familiar with that pose and I don't even have the UHG. Did you also install a skidplate? I came in contact with a guy named Gordon who lives in the bay area who was making and selling these. Based on how low that 2nd alternator hangs below the front of the van I would be afraid of damaging it. A parking spot with a slightly higher than average curb and BAM! Not to mention the rocks, ruts, mud, and sand I usually drive through..

By the way, I also agree that these can be properly installed in such a way that they don't damage cooling lines; but it looks challenging..

[InterBlog]

Someone should make a "wall of fame" page for that pose generally.

Here's my submission - my husband last summer, after flying cross-continent with a Valterra blade valve in his carry-on baggage. He was coming to join me in Canada anyway, but it's pretty harsh to complete an exhausting 12-hour flight sequence, only to immediately get down on the ground to replace a bad valve.



I know that the opinions on this vary, but I'm very glad we don't have a macerator. However, gravity drains are not foolproof either. These Valterra valves are the pits (or a word that rhymes with pits) - short lifespans and seal failures occur without warning. If your rig has one, I recommend carrying a spare at all times.

[Winston]

Originally Posted by kite_rider

Did you also install a skidplate?

No . . . (not yet?).

In a bit of irony - - we found ourselves in that 'pose' again one afternoon in some remote K-Mart parking lot. Equipped with radiator hose 'Bandaids' . . . a handful of helical metal hose clamps - - we successfully 'patched' the radiator hose until again replacing it several thousand miles down the road.

We hadn't yet replaced the only protection offered, the factory plastic shield, when we managed (in the dark-of-night while attempting to maneuver into a wooded campsite) to snag the alternator wires on a too-tall remaining stump of a small sapling apparently removed to 'clean-up' the campsite. Virtually all the wires were pulled off the alternator but, fortunately, the unprotected armature wire that runs through an opening in the Nations alternator shell was not damaged. We were able to restore things the following morning with our small doctor's bag of tools we carry for such contingencies.

Needless to comment that the plastic skid-plate was immediately reattached. We think we have the 'dangers of parking' under control, but still worry about random 'items' on the road and those occasional off-road experiences.

Despite these travails . . . and even with our 800 watts of solar . . . we have occasionally found this alternator to be essential in maintaining our 'consumptuous' electrical budget and do not regret its installation.