Community Forums

Golfer Guy · 12-09-2019, 08:20 AM

I would like to have a way to quickly see how much solar is coming in on my 2100 watts of solar panels. There must be a way to add a meter and wire it to the solar controller but I don't know how to do this myself. Anyone know what gauge I could use and how to add it to my system? Always like more gadgets and displays.

I have the Magnum PT100 solar controller with the Magnum ME RC50

okcnewbie · 12-09-2019, 08:26 AM

It's hard to imagine you have 2k plus solar without a meter/shunt.

If you don't have one than that's what you need.

Luv2go · 12-09-2019, 10:16 AM

The PT100 can be networked with the inverter and remote, however you will likely have to change over from the RC-50 to an ARC-50 to get the solar production data from it. I'd contact Sensata or your solar installer for more details.

To monitor actual system charge state you'll need a shunt as okcnewbie advises.

Golfer Guy · 12-09-2019, 10:33 AM

I have the Magnum BMK Battery shunt, what I want is a digital display that I can add to the dash or someplace easily seen with a readout of how much solar harvest is coming in at any time. I want to see this at a quick glance not going to the overhead cabinet where the AME-RC is located.

I have the state of charge on my phone along with what the battery consumption +/- is at any given time. I have all the historical data, battery cell temps, cell volts, current volts etc. Just not a solar harvest display. I know how much power is going to or from the battery bank, +/- consumption. What I don't get is the breakdown of harvest + (solar ) and consumption -(refer, parasitic, AC, etc.)

Bobby F · 12-09-2019, 11:28 AM

I like the old reliable:

https://www.amazon.com/Victron-Energ...5916069&sr=8-4

(The Victron.)

Here's a video of what you get, how it goes in - https://d1y6jrbzotnyjg.cloudfront.ne...2XWKZ35EOVO4XA

Luv2go · 12-09-2019, 11:44 AM

Note I was writing this while Bobby F was posting, the BMV712 itself will simply duplicate what you get from the RC50, you need to add the method of getting solar production to get what you want, that I try to explain below:

To measure solar production you need the charge controller to tell you what it's produced, or another way to measure production. As near as I understand, your current setup won't do that. So you need to add something that will tell you what the solar produces.

One option would be to add a Thornwave PowerMon monitor to the output of the charge controller. It would monitor the amount of charge from the solar only with a Bluetooth app.

It will need to be wired into your system and will use a new shunt in the negative wire from the charge controller to the battery. It does not have a display and uses the smartphone app as one. It is relatively easy to install as all the wiring will be in the basement compartment(s).

This option is not very sophisticated and will not give you things like percentage of harvest vs consumption, but it will definitely tell you how much harvest you are getting and you could do some math with info from the RC50 to get what you asked for for regarding consumption over the day vs production over the day. It would need to be manually reset each night to accurately keep track of the harvest daily.

Another possibility would be to replace your charge controller with one that has a Bluetooth interface like a Victron SmartSolar 150/100 which I believe is equivalent to your PT100 in terms of capability. Not cheap but if you combine it with a BMV712 it will give you most or all of what you asked for.

Bobby F · 12-10-2019, 09:45 AM

"Note I was writing this while Bobby F was posting, the BMV712 itself will simply duplicate what you get from the RC50, you need to add the method of getting solar production to get what you want . . . Another possibility would be to replace your charge controller with one that has a Bluetooth interface like a Victron SmartSolar 150/100 which I believe is equivalent to your PT100 in terms of capability."

Yep, completely correct. After I submitted, it occurred to me that I get that second Bluetooth screen from the Victron controller. Between the two Victron components, I get all of that info.

C.Martin · 12-10-2019, 12:21 PM

Yeah...if you are specifically looking for PV output...I'm not sure. You might look into Magweb...a Magnum device used to record system parameters for viewing via web portal.

I have the Victron SmartSolar MPPT 150/100. It can be viewed via Bluetooth app or plugin on Smartphone, Tablet, or Laptop. I have an iPAD mini on my A-pillar...which I sometimes use to monitor Solar.

The next level for Victron is one of thier many Remote Management devices...like CCGX, Venus GX, GSM device, etc...they are capable of sending data packets for retrieving on the VRM app.

Might see what parameters the Magweb device tracks...to see if it answers your needs.

10 fan · 12-10-2019, 08:29 PM

I was doing some capacity testing and noticed the arc-50 was showing soc 86% and all 7 200ah LPO4 said soc 94% (all have their own read out, soc, voltage, temp). I continued and by the time the arc said soc 19% all the batteries said soc 62%. I called magnum and was told their BMK does not use the same algorithm as lithium BMS. They said to use voltage not SOC. Are you kidding me. I went with all Magnum so everything would work together including the AGS. I'm thinking of adding the Victron BMK so I have an accurate SOC inside the coach and can compare it to the magnum to set the AGS.
Wanted to share this so Magnum users with lithium batteries will know the SOC may not be correct.

R.Wold · 12-11-2019, 12:33 AM

This is what I use and there are multiple pages of info, different views, you can access the data live via blue toothetc. “Grid” will show either shore power of generator, depending. Battery % also shows watts and amps, negative or positive depending if you are charging or discharging, or both.Easy to use, quick access to all the info you could possibly need. “PV Charger” Is your solar output in watts. I got mine at inverter supply. Also have the BMV 700.

This combination also allows alarms and automatic shut down at a programable voltage to protect your batteries form over discharging.

Obviously you’d want to check compatibility with your equipment. All my stuff (inverter, MPPTs, etc) is Victron.

https://www.invertersupply.com/index...ucts_id=185857

Wish Id known about the snappy mount plate for both the CC and BMV but Im getting ready to upgrade to a new coach so I’ll use it there.

I just downloaded the Victron app and will play with thst tomorrow. Lots of good info here

https://www.victronenergy.com/live/v...art-networking

R.Wold · 12-11-2019, 12:41 AM

Quote:

Originally Posted by 10 fan

I was doing some capacity testing and noticed the arc-50 was showing soc 86% and all 7 200ah LPO4 said soc 94% (all have their own read out, soc, voltage, temp). I continued and by the time the arc said soc 19% all the batteries said soc 62%. I called magnum and was told their BMK does not use the same algorithm as lithium BMS. They said to use voltage not SOC. Are you kidding me. I went with all Magnum so everything would work together including the AGS. I'm thinking of adding the Victron BMK so I have an accurate SOC inside the coach and can compare it to the magnum to set the AGS.
Wanted to share this so Magnum users with lithium batteries will know the SOC may not be correct.

The problem with state of charge expressed as a percentage is that there is a small but cumulative error as time goes by. After a while its way off. It was all explained to me and made sense at the time but I really cant articulate why at this point. I just accepted it at the time. But the solution is to recalibrate periodically.

But voltage is always correct and is more important with respect to preserving and protecting your batteries than SOC, which is probably why that suggestion was made.

Luv2go · 12-11-2019, 01:06 AM

FYI, for LifepO4 batteries using voltage to determine state of charge is almost useless, it's well documented (the discharge curve is very flat and the knees are very sharp).

It's more likely that the Magnum ARC's Peukert coefficient and charge efficiency settings are set for lead acid, they both should be changed for LifePO4 batteries. Victron allows these to be changed and I use 1.02 and 99% respectively on my BMV.

The Magnum person should have known these things, poor training IMHO.

R.Wold · 12-11-2019, 01:28 AM

This is the overview when I log in to the VRM portal on phone or ipad - very handy

C.Martin · 12-11-2019, 03:25 AM

If you add the Victron BMV-712...you can replace your Magnum Shunt with the Victron Shunt...and still attach the Orange and Blue Magnum BMK sense wires to keep the display on your ARC remote. If you can get it to calibrate, it might be useful still as an AGS trigger or AC-IN trigger...might have to skew the parameter if the accuracy has drifted.

All these little SNAFUs with LiFePO4. I have my eyes on a set of Lifeline AGMs next year. ADD inability to keep ME-BMK to the list...along with temperature sensitivity...and a egg timer algorithm for a BIM. It may be the way of the future...but it comes with a few headaches.