All-in-One RV Inverter, Charger, B2B and Solar Controller

[booster]

I got a popup ad recently that mentioned a product that is allegedly able to replace essentially all the equipment in an RV, off grid cabin, etc. Yeah they must monitor and sell information about what articles I read

This is the unit at Don Rowe who is a very reputable place so no problem there. I looked it up separately as I never click ad links and it didn't say where it would go.

All in one unit

Size is quite small at 19.7 x 12.2 x 6.2 in and weight only 33#.

3K PSW inverter

100 amp charger

Two MPPT 50 amp inputs for solar or alternator charging that could be paired for 100amps in from one source or maybe 80 alternator and 20 solar, I think.

All controlled on single provided remote panel, it appears.

Reasonably priced compared to good quality individual parts.

It certainly would violate my desires for no single failure points, but could be very useful for those doing a moderately sized lithium conversion if the inputs are all handled properly in the unit. I have not had time to scour the instructions so see exactly how it works at this point.

Anybody got any opinions on if this might be useful for some people looking for an easy, simple, upgrade with low space used and weight probably saved?

 

[booster]

I did find some time to go over the manual, which is 56 pages so fairly detailed but nowhere near the 240ish pages for our Samlex unit we got last year.

It has some interesting features if you were looking for an all in unit, for sure. Good power for charging and inverting, reasonable size, quite low weight. As with all this kind of thing, it has stuff I am not thrilled about, but that pretty normal.

For the charging section it is the kind of typical profile of the more modern AGM era charging. Bulk, absorption, float, rebulk on a timer at 7 days, repeat. Not great for lithium, especially with the probably required rebulk to full all the time while in storage if plugged in.

Transition to float is amp and voltage based, but done internally so the amps control will be influenced by any loads that are on and would need to be compensated for during setup. Voltage does not seem to have a remote reference for the battery which I think every charger should have, especially with lithium.

3000 watt inverter with typical settings and does have easy on/off if you don't want to use a standby setup. Should have enough reserve capacity to start things like AC even though it is a high frequency design which don't start stuff as well as low frequency, very heavy, low frequency transformer designs.

It has an automatic transfer switch internally and said it prioritizes power to van by reducing charging to prevent breaker trips.

It didn't explain the exact system, but seemed to be saying it does automatic neutral to ground bonding, which is a bit plus and safety feature.

So the charging and inverting pretty much cover those well for most users.

The two DC inputs it has are really what sets it apart, but again the system wasn't detailed completely in the manual.

It has two 50 amp inputs on the unit. Each one can have a solar and alternator attached on separate contacts which it can prioritize. The two outlets can be paralleled also so you could get 100 amps of alternator charging for instance, and I think that solar could also be hooked up the same time. You would probably prioritize alternator as first choice and solar second and I assume it would shut off the solar input and run only the alternator until the alternator charging went to zero when it would turn on the solar. It also seemed to be saying that those inputs are able to take higher amp availability and limit it to 50 on each so no BtoB or other current limiting needed. It didn't specifically say it, but implied that the output from those two DC inputs would then charge to same profile as the charger. If it the is done that way it is very nice, as our Samlex has a 12v input for solar, but it is just a pass through. This unit is an MPPT charger for both solar and alternator I think.

As I mentioned earlier, this would not be the right unit for us as our system is too large in battery capacity and charging rate and set for midrange charging for the lithium.

But if I had a class b with the typical 2 AGMs at 200ah, a Tripplite, a generator or not, and solar or not that had not been modernized yet, it could be a very good and easy, near drop in way to go to 300ah or so of lithium with a big charger and inverter and much easier than piecing together a compatible bunch of independent devices.

 

[Winston-ClassB]

Why does the alternator require its own input? Why not just connect the alternator to the battery?

 

[booster]

Why does the alternator require its own input? Why not just connect the alternator to the battery?

Hi Winston, good question.

The alternator/solar inputs are current limiting which solves the very high acceptance of the lithium batteries. They will easily pull way more than a 280amp alternator can provide is you have even and moderate battery bank.

The other benefit, which I think it would do but the manual was kind of sketchy, would be that the batteries would get the alternator output converted to the charge settings of the shore charger so the battery sees all the same, correct, charge profile. If that is correct, it makes life pretty easy and you can run on any alternator regulator, including a plain old internal one.

As with any of this stuff, claims and descriptions are one thing and reality can be quite different. I have found not testing on that unit yet. If it does all the items that way it could a very cost effective, small, light unit the would replace several normal components.

 

[Winston-ClassB]

"Current limiting". Hmmm. Benefit or detriment? Not sure we want some intermediary box/controller limiting the current available from our solar panels or alternator. Of course we have a slightly different set-up having a 2nd alternator with its own external regulator that allows the direct setting of alternator charge current.

But this raises the interesting question - - to which you hinted - - does this new all-in-one controller serve a B2B function? It's one thing to limit current (how does it do that - - a voltage step-down converter/inverter?), but we've found that more often we need to step-up the voltage to achieve a satisfactory high current charge rate.

And it seems we cannot avoid our continuing 'charge profile' debate - - you adhering to the standard bulk/absorb/float (with "re-bulk"?), we, continuing our advocacy of maximum available current-to-constant voltage. Can this unit be programmed for constant voltage?

As an aside, we recently changed the 'programming' of our MidNite solar controller. Unlike the Magnum, MidNite Solar follows the "traditional" bulk/absorb/float convention and does not provide a Constant Voltage mode . . . so we have now programmed this controller for 1 minute of bulk and absorb so that it quickly switches to "float" - - where we set the float voltage to our target constant voltage (presently 13.4 volts).

Finally, we share your obvious concern for product manuals that do not adequately describe their product's capabilities and configuration. We've occasionally had to "move-on" and look for alternative solutions because we could not determine whether the product we were reviewing met our requirements.

We'll stay tuned to this thread and hopefully learn more about this product.

 

[booster]

"Current limiting". Hmmm. Benefit or detriment? Not sure we want some intermediary box/controller limiting the current available from our solar panels or alternator. Of course we have a slightly different set-up having a 2nd alternator with its own external regulator that allows the direct setting of alternator charge current.

But this raises the interesting question - - to which you hinted - - does this new all-in-one controller serve a B2B function? It's one thing to limit current (how does it do that - - a voltage step-down converter/inverter?), but we've found that more often we need to step-up the voltage to achieve a satisfactory high current charge rate.

And it seems we cannot avoid our continuing 'charge profile' debate - - you adhering to the standard bulk/absorb/float (with "re-bulk"?), we, continuing our advocacy of maximum available current-to-constant voltage. Can this unit be programmed for constant voltage?

As an aside, we recently changed the 'programming' of our MidNite solar controller. Unlike the Magnum, MidNite Solar follows the "traditional" bulk/absorb/float convention and does not provide a Constant Voltage mode . . . so we have now programmed this controller for 1 minute of bulk and absorb so that it quickly switches to "float" - - where we set the float voltage to our target constant voltage (presently 13.4 volts).

Finally, we share your obvious concern for product manuals that do not adequately describe their product's capabilities and configuration. We've occasionally had to "move-on" and look for alternative solutions because we could not determine whether the product we were reviewing met our requirements.

We'll stay tuned to this thread and hopefully learn more about this product.

The current limiting, at least to me, is a very important feature in this unit. The current "best practices" for lithium is that charging should be done at 20-.40C to prevent damage that shortens life. As with all the best practices for lithium over the the years this could change tomorrow or be true and I do recall seeing some tech papers that did back up the idea, including with sectioned SEM pix of the dendrites in the separation layer. I see the .2-.4C quite a bit with .2 the recommended. Some others say .5C max. Some are still on the 1C and higher theory. You have quite a bit of battery capacity. How do you prevent the alternator from overheating because of the high acceptance of the bank? Cycling on thermal switch for the Balmar that will drop you to 50% until the alternator cools off?

We do not adhere to the full 3 step or 4 step charging unless we have to like with the solar. Our Samlex charger does constant voltage bulk/absorption charging with no float, it just goes into standby and monitors voltage. When it hits the rebulk voltage it comes on and repeats the process. Very good for storage as eliminates the constant power to the float on the batteries, which again is said to not be good for battery life but never quantified. Solar is like yours and done the same but only turned on in the midrange so never floats in reality. The alternator regulator is set 3 stage because it has to, but it too is only used midrange so never floats. The Victron monitor will turn on the engine charging at 30% if I have the power to it on. I can also run it on an override switch to bypass the Victron and just watch the SOC on the Victron to recover back to near 80% and then shut if off. The regulator is set at 13.8v bulk and will go to float in a couple of minutes and float is low at 13v so does nothing for charging. We charge at a constant 120 amps from the second alternator which is just about at .2C and plenty fast enough for us base on our use patterns.

A little questionable, but I certainly hope it would work as a B to B with a the profile of the shore charger, but not confirmed as you say.

That is the way we have our Blue Sky controller programmed, and with a long max absorption time as that fits how we use it. I generally leave the solar off until we hit about 50% SOC and then turn it on. The 300 watts we have basically break even some of the time, gain a little or lose a little depending on conditions. We use low voltage for the absorption, IIRC 13.4v so no chance of over charge and float is basically used as a just in case thing at is low at about 13v. On most trips the solar stays on full time once on at 50% and just bounces around the 40-60% SOC.

 

[Winston-ClassB]

We occasionally see 200 amp charge rates when we're experiencing "big sun" and have our 2nd alternator running. But for the most part, we charge at 150 amps or less. With our 600+ah pack, we're pushing 0.3C but, again, only occasionally and the rest of the time we're closer to 0.2C. You can see why we would not want to have a 50 or 100 amp limitation on charge rate. It seems, though, that your suggestion when introducing this all-in-one Don Rowe product was aimed at "moderately sized lithium" systems and, to that end, the 100 amp limitation may not, in fact, be a limitation.

Your term "lithium acceptance" is interesting. That term suggests that the lithium pack determines and controls the charge rate and, as lithium has such a 'high acceptance', lithium will necessarily 'demand' more current than is safe. Obviously under some circumstances that could be true. But the purpose of defining 'charge profiles' is to let the charging device define and control the charge rate, not the lithium batteries themselves. So, for example, our external 2nd alternator regulator is adjustable. Yes, if we turn the setting too high, we could literally exceed the 280 amp rating of the alternator. We have a thermocouple attached to the alternator which provides real-time alternator temperature and, over a period of time, we have played with the regulator to determine the max charge rate that doesn't over-temp the alternator. The difficulty being, however, on a cool 50 degree day while driving along an Interstate the alternator stays cool at twice the maximum safe current on a 90 degree day while parked/idling. Our DIY regulator does not automatically lower the current when high temperatures are reached (as did the Balmar), so, when 'hot and stopped', we have to monitor this gauge.

Please recall that we maintain our power supplies (chargers) "on" all the time (when power is available) contending that attaching a power supply of precisely the same voltage as the battery pack cannot hurt the battery as the battery "doesn't even know" the charger is attached. This, we understand, is what some refer to as "floating". You indicated in past discussions that you read a 'white paper' that took an opposing position saying floating is bad. We'd love to review that white paper. If you have a copy or the URL, please forward it. Thanks.