Let's see your solar setup.

[R.Wold]

Originally Posted by cinergi

Those of you running the battery bank / inverter at 24v+, what are you doing to provide 12v to the RV? Some of the 12v loads are quite heavy (hydraulics, macerating toilet, water pump, etc). Similarly, what about keeping chassis batteries charged? And finally the alternator (or do you even connect that to the house system)?

Thanks!

My inverter is always on and it powers all AC in the coach including the converter, and of course along with the solar, it charges the battery bank. The only problem is that if I push my battery usage to the low-battery cut-off, and cause the inverter to shut down, I lose power to my 12v stuff too. But after a couple of those episodes, I tend to pay attention to what I'm doing a little mote.

You bring up an interesting point though. I never thought about the demand I’m putting on my converter and so far it’s handling things just fine. The slides are probably the biggest load. But its just the OE 2010 Newmar gasses converter so I wouldn’t be surprised if it fails eventually. Guess I’ll check specs on it.

Alternator stays out of all of it - feeds the engine start battery only.

[tmelsonjr]

[jcussen]

Originally Posted by R.Wold

My inverter is always on and it powers all AC in the coach including the converter, and of course along with the solar, it charges the battery bank. The only problem is that if I push my battery usage to the low-battery cut-off, and cause the inverter to shut down, I lose power to my 12v stuff too. But after a couple of those episodes, I tend to pay attention to what I'm doing a little mote.

You bring up an interesting point though. I never thought about the demand I’m putting on my converter and so far it’s handling things just fine. The slides are probably the biggest load. But its just the OE 2010 Newmar gasses converter so I wouldn’t be surprised if it fails eventually. Guess I’ll check specs on it.

Alternator stays out of all of it - feeds the engine start battery only.

So your converter powers all your 12 volt loads, with no 12 volt battery?

[R.Wold]

Essentially yes with the exception of one 12v light over the drivers seat which is tied to the ignition. I eliminated the 12v house batteries and run the inverter off the lithium battery bank (32.8v) Its probably not the most efficient way to go about it because I’m inverting from 32v DC to 120 AC, then converting back to 12v DC so I have my share of parasitic loss. But its not enough to worry about and I don’t have any big 12v loads other than the slides and those are short duration.

Also with no 12v house batteries, I no longer have “emergency start” capability but I could always plug in a battery charger if I somehow managed to kill my start battery.

This was convenient and it works and I never gave it a second though. But this question got me thinking about the load I’m putting on my converter, so I guess I’ll stop taking it for granted and look into it.

Another little conundrum is that the Victron 24/3000 can only charge up to 28v so the only way I can fully charge my Lithium batteries is with solar. Shore power or the genny won’t do it. But its manageable as long as I’m somewhat strategic about it.

[KirkDB]

Originally Posted by R.Wold

Essentially yes with the exception of one 12v light over the drivers seat which is tied to the ignition. I eliminated the 12v house batteries and run the inverter off the lithium battery bank (32.8v) Its probably not the most efficient way to go about it because I’m inverting from 32v DC to 120 AC, then converting back to 12v DC so I have my share of parasitic loss. But its not enough to worry about and I don’t have any big 12v loads other than the slides and those are short duration.

Also with no 12v house batteries, I no longer have “emergency start” capability but I could always plug in a battery charger if I somehow managed to kill my start battery.

This was convenient and it works and I never gave it a second though. But this question got me thinking about the load I’m putting on my converter, so I guess I’ll stop taking it for granted and look into it.

Another little conundrum is that the Victron 24/3000 can only charge up to 28v so the only way I can fully charge my Lithium batteries is with solar. Shore power or the genny won’t do it. But its manageable as long as I’m somewhat strategic about it.

I did exactly the same thing with just the converter powering all 12v loads on my 5th wheel. Worked great until running my 6 point hydraulic leveling system. It would act funny at times; stopping in the middle of a leveling sequence. Also, my fuel station (toyhauler) started running the fuel pump for the hand pump every time we ran the leveler. So definitely a low voltage issue running on just the converter itself. Adding in a small ATV battery cured that. I eventually swapped out the factory converter for a victron 24->12v converter. I set the voltage on the victron converter to match the atv battery float voltage and all has been well since. I would avoid running the converter on its own unless you are certain it easily exceeds your power requirements. I measured around 120a draw off the battery when running my levelers.

Also, I charge my 24v (4 cells parallel 8 sets of cells in series) lithium bank to 27.2v which the multiplus and Quattro can handle no issue. You only lose around 5-10ah between 27.2v and 29v. Take a look at your manufacturers charge / discharge curve. Also, lithium batteries really don’t like being charged to their max. You are also more likely to run into a cell over voltage condition charging to 29v. Personally I wouldn’t charge over 28v. Just not worth the tiny gain. Likewise, discharging below 24v doesn’t buy you much and risks a cell going too low.

Even with my very conservative settings I’m getting around 395ah from my 400ah bank. If I push the extremes I can milk about 420ah out of it but I put myself at risk of damaging my bank.

Just my 94 cents

Kirk

[geni406]

RV Solar did my install because I try to not do anything dealing with electric.

I had 8 - ZS 170 W panels installed nearly 1 year ago. I have the original 8 wet cell batteries, so no upgrades there yet - I am running them down and out before I change to lithium.
I have a Victron Blue Solar Charger 150/100, a Victron Blue Charge controller BMV 712 with remote/blue tooth monitor, and a VB Temp Sensor.
I had solar pre-wire, but Bill couldn't get to it, so he ran more wire in my front cap, by the driver side post.
I have a 2800W pure sine inverter (Magnum.)
All electric coach. 8 6V batteries currently wired in series and parallel.
When my batteries do fail I will have LiFePO4 installed with heating pads and insulate the battery box with a second inverter for the fridge and a soft start for the air conditioner. (I have been known to camp in the snow.)
While in 'high sun' areas - Alaska in the summer - I ran the generator very little, just when I wanted coffee or to heat my food. I could use the keurig or microwave with the 20 hours of sun, for a short time while dry camping, or running my second air on 30amp.
I am quite happy with my no tilt solar, it keeps my batteries up, as I do not plug in when at home. I do still exercise my generator under a load. I usually go out and cook some dinner.

[Bobo_Wickersham]

2016 Dutchstar 4313

We changed out our OEM GoPower PWM Solar Charge Controller with an equal size Victron MPPT 100/30 Rev 2 controller, and Venus GX connected to my WiFi in RV. I can remotely monitor solar progress in real time

[TechWriter]

I did my 735 watt 3-panel solar install in 2012.

[jcussen]

Just finished my "recharge the Tesla" project. 5200 watts on the roof [S&B] Magnum 4448, two Midnite Solar 250 volt controllers and three 7 kw leaf gen 2 battery packs. As close to driving for free as you can get, if you discount the upfront costs.

[R.Wold]

Originally Posted by KirkDB

I did exactly the same thing with just the converter powering all 12v loads on my 5th wheel. Worked great until running my 6 point hydraulic leveling system. It would act funny at times; stopping in the middle of a leveling sequence. Also, my fuel station (toyhauler) started running the fuel pump for the hand pump every time we ran the leveler. So definitely a low voltage issue running on just the converter itself. Adding in a small ATV battery cured that. I eventually swapped out the factory converter for a victron 24->12v converter. I set the voltage on the victron converter to match the atv battery float voltage and all has been well since. I would avoid running the converter on its own unless you are certain it easily exceeds your power requirements. I measured around 120a draw off the battery when running my levelers.

Also, I charge my 24v (4 cells parallel 8 sets of cells in series) lithium bank to 27.2v which the multiplus and Quattro can handle no issue. You only lose around 5-10ah between 27.2v and 29v. Take a look at your manufacturers charge / discharge curve. Also, lithium batteries really don’t like being charged to their max. You are also more likely to run into a cell over voltage condition charging to 29v. Personally I wouldn’t charge over 28v. Just not worth the tiny gain. Likewise, discharging below 24v doesn’t buy you much and risks a cell going too low.

Even with my very conservative settings I’m getting around 395ah from my 400ah bank. If I push the extremes I can milk about 420ah out of it but I put myself at risk of damaging my bank.

Just my 94 cents

Kirk

I didn’t do the math, but you must be using LiFePO4 lithium’s. I’m using using Li-ion (4.2v cells) and I’m only charging each cell to 4.1v. So no over charge issues. 8 cells per, so 32.8v. So the inverter/charger will get it to 28v on shore (or Gen but I NEVER run it) and solar brings it up the rest of the way to 32.8v

[Vickie 4369]

This has turned out to be a really great thread lots of info to absorb here, Great Job by all involved.

Ted.