Renogy NEW Battery Monitor shunt mounting??

[Sagecoachdriver]

Renogy introduced a Battery Monitor and I see in their reviews that the shunt doesn't come with a mounting pad attached to the shunt. Has anyone out there bought one of these battery monitors and how did you mount the shunt? All of my solar components are from Renogy and when I saw this BM, I liked the display having all the readings on the screen at once rather than having to scroll thru for readings. Also, the size and shape of the monitor itself fits where my old BM is. I know Victron has good BM's , but I don't need or want one with bluetooth, just a good visible full display. Renogy appears to have knowledge of the fact but aren't currently doing anything about it. Wonder if another manufacturers shunt would work or are they proprietary.

[TitanMike]

If I were to buy one the lack of a mount on the shunt wouldn't even slow me down. A short piece of soft copper tubing hammered flat holes drilled in ends, bolt to battery negative terminal, bolt shunt to other end. If you have a HUGE battery bank with a large inverter, use two pieces of flattened copper pipe. I prefer soft copper to the hard copper as the soft stuff is annealed and less prone to cracking. If you only have rigid copper pipe just heat it until it BARELY starts to turn red (dark room helps) and then let it air cool. You'll now have soft copper and NO, it does not need to be quenched to be annealed.

I wanted to mount it on a wall I'd just use a heavy connector cable and use a couple of aircraft type cable clamps, one on each cable with shunt in the middle.

Most battery monitors come 50 milivolt shunts.. Just remember that you'll have to transfer the circuit board that's mounted on the supplied shunt. That part could well be proprietary.

[Sagecoachdriver]

I ordered it last night and it was supposed to be here Wednesday. But FedEx out did themselves and delivered it late this afternoon. Yep, the shunt has no insulated base. So I looked at my old Xantrex shunt and saw it was just a block of ABS with counter sunk holes for the bolts. So I made one out of plywood and have it up and running. But I used 1/2" plywood and the bolt heads aren't countersunk enough and just clear the back. Plus the bolts aren't long enough and the nuts only go on about 1/3 of the way. Going to try again tomorrow using 3/4" plywood counter sunk deeper using longer bolts. Then I will seal the back covering the bolts for added protection.
Another option is to use a shallow ABS project box shown below. Dimensions are perfect and I can bolt the box to the steel wall in the battery compartment and mount the shunt on the removable screw on top.
First impression of the battery monitor is great!. I like the small size and full display, no more scrolling.

Just found a shallow gang box at Home Depot, a little deeper but I can just drill 2 holes for the bolts and screw it to the battery compartment wall.

[Sagecoachdriver]

Made a mounting block out of oak. Counter sunk holes. treating with Thompsons water seal. Hope to install this afternoon.

[mjbenedict]

Originally Posted by Sagecoachdriver

Made a mounting block out of oak. Counter sunk holes. treating with Thompsons water seal. Hope to install this afternoon.

Wood is not a good insulator. With moisture you could take from the resistance and affect your reading. At least make sure there is some rubber between the wood and the metal.

[Sagecoachdriver]

Originally Posted by mjbenedict

Wood is not a good insulator. With moisture you could take from the resistance and affect your reading. At least make sure there is some rubber between the wood and the metal.

Good idea, will place a rubber pad between wood and wall.

[ependydad]

Once you figure it out in wood, this would make an excellent 3D printed project... if you know someone with a 3D Printer!

[babock]

Originally Posted by mjbenedict

Wood is not a good insulator. With moisture you could take from the resistance and affect your reading. At least make sure there is some rubber between the wood and the metal.

Would not affect the reading by a fraction of a percent. Mounting on wood by itself is not a problem.

The resistance of a 500A/50mV shunt is 0.0001Ω.
The resistance of wood is likely in the 100s of thousands of ohms.

[mjbenedict]

Originally Posted by babock

Would not affect the reading by a fraction of a percent. Mounting on wood by itself is not a problem.

The resistance of a 500A/50mV shunt is 0.0001Ω.
The resistance of wood is likely in the 100s of thousands of ohms.

Now do damp wood.

[babock]

Originally Posted by mjbenedict

Now do damp wood.

LOL....I don't care how damp the wood is...do the math! It could be down to 1Ω and it still wouldn't matter.

[TitanMike]

Originally Posted by babock

LOL....I don't care how damp the wood is...do the math! It could be down to 1Ω and it still wouldn't matter.

Also take into consideration the working voltage of 12-14 volts versus 120 volts.

I guess it might make a difference if the wood was Balsa and the "wet" was salt water

[Sagecoachdriver]

Went to HD and bought a plastic shallow gang box for $1.25. I drilled holes for the bolt and mounted the shunt and box to wall. Connected the cables, all done. Will take a photo later today.

[Sagecoachdriver]

Photo of the plastic shallow gang box I used as the shunt mount.

[Tom48]

Nice looking install. Very resourceful. When you're ready to write a feature by feature comparison with Victron and Bogart Engineering's Trimetric is the next report I'd like to see.

[TitanMike]

Originally Posted by Tom48

Nice looking install. Very resourceful. When you're ready to write a feature by feature comparison with Victron and Bogart Engineering's Trimetric is the next report I'd like to see.

From what I've been able to gather so far from Renogy's literature on this monitor I don't think it is really in the same class as the Victron or Trimetric.

In reading the manual the SOC % appears to be calculated merely by comparing current battery voltage to a pair of user set voltages that represent 100% SOC or 0% SOC.

It does not appear to be a "Coulomb Counter" that actually measures volt/amps in or out and corrects using Peukert factor. Also no means of reading battery temp for for corrected readings.

It looks nice but may come up short measuing and displaying accurate SOC and Time Remaining on LiFePo batteries that have extremely flat discharge voltage curves compared to the Lead Acid and it's variations.

Unless I missed something in the rather simple manual, that's what I see.
Looks like a nice Voltage, current, display along with a time remaining on the batteries but that last display may be of questionable accuracy.

Here's the manual so each one can read and judge for themselves.

BTW, here's some info that shows why the Peukert Factor is important in predicting "run time" for a battery. Not the different performance for the various lead acid battery types.

Battery Runtime
Figure 1: Available capacity of a lead acid battery at Peukert numbers of 1.08–1.50. A value close to 1 has the smallest losses; higher numbers deliver lower capacities. Peukert values change with battery type age and temperature:


AGM: 1.05–1.15
Gel: 1.10–1.25
Flooded: 1.20–1.60

Source: Von Wentzel (2008)


Note: Peukert Factor doesn't apply to Lithium battery chemistry as they are almost 100% efficient at all discharge rates. No chemical reaction to wait for as in Lead Acid batteries.

[babock]

Kinda interesting that the monitor doesn't mention Peukerts constant at all. That's kinda worrisome.

[Tom48]

Thank you TitanMike.

[Sagecoachdriver]

Seems more accurate than my old Xantrex battery monitor. Mike, your last Post in over my head. Hope I didn’t waste my money!

I don’t use the time remaining. Just concerned about the discharge rate and total ah remaining. Used to be concerned about low voltage with the flooded batteries. The Lithium is not an issue with voltage

[TowPro]

I take a 2 or 3 in piece of 1/2" coper pipe and hammer it flat. Drill a hole In both ends big enough for battery and isolator stud and use this to mount isolator

[Sagecoachdriver]

Chatting with Babock, we determined that the shunt as originally mounted on the shallow gang box was too deep and was touching the battery flange. So I removed it yesterday and with my bench belt sander removed about 1/2" off the open back. When purchasing the gang box, I also picked up a plastic gang box cover. I cut it down to fit the back of the gang box so it acts as an insulator for the bolts. Finally, I remounted it and attached all the cables and wires.
Photo on top was original and bottom is sanded down providing clearance.