Critique my solar charger/battery monitor setup?

[luthj]

Victron will definitely let you set a custom output limit. You can also change the MPTT algorithm if it sweeps too low and makes the DC-DC supply trip to overload mode.

I would keep an eye on it, just to make sure the victron doesn't pull the input voltage down below about 30V or so.

 

[luthj]

You're talking about putting an inverter on the tow rig and run a 120v extension cord back to my factory installed converter/charger? Would I mount the inverter under the hood? What size ~500w?

You need to size based on your converter. Whatever its charge output is, plus 50% for power factor and efficiency losses. The inverter could be located wherever appropriate. Most are not going to work under the hood, so you would need to put in a dry space.

 

[Buddha.]

You need to size based on your converter. Whatever its charge output is, plus 50% for power factor and efficiency losses. The inverter could be located wherever appropriate. Most are not going to work under the hood, so you would need to put in a dry space.

If I did that I'd probably buy a new battery charger and mount it up front by the solar charger. My existing converter/charger is 20' back and charging through 6 awg wires, that can't be a great setup.

 

[luthj]

In that case its probably cheaper to try out the 12-36V supply. You already have the expensive quality solar controller.

 

[Bayou Boy]

If I did that I'd probably buy a new battery charger and mount it up front by the solar charger. My existing converter/charger is 20' back and charging through 6 awg wires, that can't be a great setup.

6AWG will flow plenty. That’s what my 5th wheel has running from the converter and I see 45 amps of charge when my batteries are down.

Your bigger issue is that you probably have a crappy WFCO converter that will cook your new GC2s. Swap it out for a progressive dynamics.


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[Bayou Boy]

The first thing you need to do is buy a Victron Bluetooth battery monitor so you can see what is actually happening.

All the rest of this is guessing without a shunt based monitor.

Never mind. I see you have that. Hook it up and run some tests.


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[Bayou Boy]

The converter I have is the Progressive dynamics PD9160A.
"Once the battery reaches 90% of full charge, the Charge Wizardautomatically selects the NORMAL Mode (13.6V) to safely complete the charge. The STORAGE Mode (13.2V) is automatically selected after 30 hours of non-use of the 12-volt RV electrical systems. The lower charging voltage in the STORAGE Mode of operation reduces battery gassing and water usage, while maintaining the charge. Every 21 hours when the system is operating in the STORAGE Mode, the Charge Wizard will automatically switch to the EQUALIZATION Mode of operation. The EQUALIZATION Mode increases the charging voltage up to 14.4 volts for 15 minutes. This increased voltage mixes up the battery electrolyte and prevents battery stratification and the resulting problems of battery sulfation."

Good. That’s the one you want.


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[john61ct]

The inverter could be run off fat cables directly from the alternator, Starter batt as the buffer.

The sizing would be large enough to hndle the load pulled by the charger at the end of the long AC output line. Also a low cutoff input voltage would be a good idea.

Neither should be larger than what the alternator can handle continuously in hot weather.

A good quality adjustable VR in between would allow that factor to be optimized, but those cost hundreds, e.g. Balmar MC-614.

So, if sticking with the stock VR on an older truck, prolly a good idea to at least put in a circuit that cuts alt production before it or its diodes start overheating.

30A is a pretty low target, but if driving over 8 hours a day should be fine.

With 3 pair of GCs, 600+ Ah, a 100A charge rate would help better get back to 100% full within 7hrs drivetime.

 

[Buddha.]

The first thing you need to do is buy a Victron Bluetooth battery monitor so you can see what is actually happening.

All the rest of this is guessing without a shunt based monitor.

Never mind. I see you have that. Hook it up and run some tests.


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That's the unit on top/middle of the image from my initial post. Still looking for opinions if I wired it correctly.

 

[Bayou Boy]

That's the unit on top/middle of the image from my initial post. Still looking for opinions if I wired it correctly.
View attachment 565492

Yes. That’s wired correctly.


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[luthj]

Make sure there is nothing connected to the battery negative except the shunt. Otherwise looks good.

 

[Bayou Boy]

Edit. I would add a negative bussbar and tie that to the shunt rather than stacking leads into the shunt itself. It’s just cleaner.


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[Buddha.]

I think my powered tongue jack(with a led light) grounds through the frame? There's only a power wire that goes to it, no ground wire.

 

[Bayou Boy]

I think my powered tongue jack(with a led light) grounds through the frame? There's only a power wire that goes to it, no ground wire.

There is a wire somewhere that leads to the negative battery post from the frame. Find it and tie it into the shunt.

Only one wire comes from the negative on the battery and it has to go to the shunt. Zero exceptions.


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[luthj]

Any loads that bypass the shunt will be invisible to the battery meter.