Remote monitoring of secondary battery and solar

Scoutman

Explorer
I'm planning out a charging system for a secondary battery to be mounted under the bed of the truck that will power the fridge, rtt, fan, etc. I have a diesel in my Dodge Ram which already has 2 batteries from the factory but as I've learned over running the fridge the past year or so, with sometimes short commute times, I'm not able to keep it running 24/7 in the summer months. Thus taking me down the road of a house battery, full time 100w solar panel and a Blue Sea smart isolator relay. Since the Blue Sea relay system doesn't have any battery monitoring I'm looking for a way to keep tabs on the status of the house battery. Furthermore since the solar would be a second charging system to the same battery I'd like to know stats from that too without overlapping monitoring from the 2 systems.

My main question is what monitoring should I look at to keep tabs on how the secondary battery is doing? Most of the solar charge controllers have leds that tell charging status and some have digital displays with a little more information. This would be fine but chances are the controller is going to be mounted someplace out of the way and not easily visible from the drivers seat. Dash space is of course at a premium so a ~7"x4" panel intended for some RV control panel cabinet isn't going to work well on my dash.

...Or should I just put a volt meter to the aux battery and not worry with where the charge is coming from. If I'm driving down the road it'll be coming from the ML-ACR but if sitting in a parking lot/campsite it will charge from the panel. This may be the simplest option but won't tell me amps in from solar or amps out from load.

Options I've looked at...

Blue Sea EV Battery Charger Display
7517.jpg



Blue Sea M2 State of Charge Monitor (pricey but packed with features)
1830.jpg


Getting a basic dual volt meter from Amazon.
61CshspZc1L._SL1000_.jpg


Running a charge controller that has a remote display like the MorningStar Sunsaver Duo (the duo has the remote display option, I don't think the single does)
 

john61ct

Adventurer
No voltage measurement will give you accurate SoC.

SmartGauge is the most accurate and simplest.

Victron BMV-702 is good out of the shunt-based ones.
 

john61ct

Adventurer
To get SoC calculation the same monitor should track amps in and out.

Also each device is resistant (voltage drop) and a point of failure.
 

Scoutman

Explorer
The more I've looked at solar charge controllers lately the more I think one with a remote display will suit me best. The Morningstar Sunsaver Duo (with remote) should do all I need on the solar front and can be mounted out of the way with the remote in view. The second output from the controller can go up to my starting batteries or it could go to a second house battery if I ever were to need one.

The charging relay from the engine should tie directly to the house battery and basically give me 2 charging sources. The remote display will only tell me valid info of what the solar is doing but would tell me battery voltage too.

I know some of this is me thinking out loud but does that all make sense?
 

Scoutman

Explorer
If you are happy with PWM, I think Morningstar duo is alright.
No idea its cost , but might expect its a good bit more than comparable but ordinary 25amp PWM display controller.
I dont see great benefit of its battery priority scheme, but I steer toward KISS projects for the most part anyway.
If its to be customised, does one need to buy software ?

Since I'm mainly going to be running a single 100w panel I haven't found any benefits to running a MPPT controller.

The Sunsaver Duo with remote display seems to run around $150-ish from what I've found online.

The customized part is only for setting custom charging set points. There are 2 factory settings 50/50 and 90/10 (selectable by dip switches) and if you don't like those then you have to purchase an $38 adapter. I don't anticipate needing to change this since the 90/10 should work for me.

https://www.morningstarcorp.com/wp-content/uploads/2015/04/UMC-1-instructions_4.28.2015.pdf

https://www.morningstarcorp.com/wp-content/uploads/2014/02/MS-ZMAN-SSD01-D1.pdf
 

jonyjoe101

Adventurer
I have been using a wireless 120v 30 amp lcd combo meter (cost me less than 25 dollars)to monitor my lithium battery. It has a relay built-in, that can let you shutoff power going to the battery, low voltage,overvoltage can also trip the relay. There is a good review of it on youtube. The meter is bidirectional measuring amps going into battery or out of battery at the same time. My battery is only 5 feet away but it works well from that distance, once programmed the sending unit works on it's on, even if it loses reception or you disconnect the meter, it's still protecting the battery.

120 volt 30 amp meter.jpg
 

reidbailey

Observer
I have been using a wireless 120v 30 amp lcd combo meter (cost me less than 25 dollars)to monitor my lithium battery. It has a relay built-in, that can let you shutoff power going to the battery, low voltage,overvoltage can also trip the relay. There is a good review of it on youtube. The meter is bidirectional measuring amps going into battery or out of battery at the same time. My battery is only 5 feet away but it works well from that distance, once programmed the sending unit works on it's on, even if it loses reception or you disconnect the meter, it's still protecting the battery.

View attachment 411325

Interesting. Do you have a link for more info?


Sent from my iPhone using Tapatalk
 

dwh

Tail-End Charlie
Since I'm mainly going to be running a single 100w panel I haven't found any benefits to running a MPPT controller.

The Sunsaver Duo with remote display seems to run around $150-ish from what I've found online.

The customized part is only for setting custom charging set points. There are 2 factory settings 50/50 and 90/10 (selectable by dip switches) and if you don't like those then you have to purchase an $38 adapter. I don't anticipate needing to change this since the 90/10 should work for me.

https://www.morningstarcorp.com/wp-content/uploads/2015/04/UMC-1-instructions_4.28.2015.pdf

https://www.morningstarcorp.com/wp-content/uploads/2014/02/MS-ZMAN-SSD01-D1.pdf

On the run so only have a minute.

Don't recall if the software and modbus bridge can change the 90/10 split. Mostly it's used to dial in the bulk/absorb/float voltages.

Also handy for long term data logging.
 

VanDominator13

Observer
Yesterday I ordered this Victron BlueSolar 75v 15a MPPT controller. This controller can be used with up to 200W (at 12v) of solar, which is about the max I'd ever see myself using.

Today I also ordered the Victron VE.Direct Bluetooth Dongle, which allows for monitoring the battery via Bluetooth connection from your phone.

I'm not normally a huge fan of "tying in" to a Bluetooth connection, but for something like this, (ie. don't need to check it every 5 minutes, but rather once per day, if that) I don't mind.

Customer screenshot from Amazon reviews:

61Oe5D2zNnL.jpg


... looks pretty awesome.

How do you like the setup?
 

LLLux

New member
On the run so only have a minute.

Don't recall if the software and modbus bridge can change the 90/10 split. Mostly it's used to dial in the bulk/absorb/float voltages.

Also handy for long term data logging.

Can you please post a link to purchase or a name/model #?
 

dwh

Tail-End Charlie
Can you please post a link to purchase or a name/model #?

To the Morningstar SunSaver Duo?

Here's the unit:

https://www.morningstarcorp.com/products/sunsaver-duo/


Here's the modbus/meterbus bridge you need to talk to it with a computer:

https://www.morningstarcorp.com/products/pc-meterbus-adapter/


Probably also need a USB to RS-232 serial adapter from somewhere. Here's a few:

https://www.amazon.com/gp/aw/s/ref=is_s_ss_i_0_8?k=usb+to+serial+adapter&sprefix=usb+to+s


The MSView software is a free download:

https://www.morningstarcorp.com/msview/
 

dwh

Tail-End Charlie
Yesterday I ordered this Victron BlueSolar 75v 15a MPPT controller. This controller can be used with up to 200W (at 12v) of solar, which is about the max I'd ever see myself using.

Today I also ordered the Victron VE.Direct Bluetooth Dongle, which allows for monitoring the battery via Bluetooth connection from your phone.

I'm not normally a huge fan of "tying in" to a Bluetooth connection, but for something like this, (ie. don't need to check it every 5 minutes, but rather once per day, if that) I don't mind.

Customer screenshot from Amazon reviews:

61Oe5D2zNnL.jpg


... looks pretty awesome.



Just remembered something I'd meant to say here, but was in a hurry back then and forgot...

That screenshot is showing data from the Victron BMV-700, which is a shunt-type amp counter battery meter. It's not showing data from a charge controller.



I didn't buy the bluetooth dongle for my charge controller. Still undecided if I want that or the LED meter. Leaning toward the meter. Only one data port on the charge controller so I don't think it's possible to use both at the same time unless there is some adapter I haven't seen yet.
 

Scoutman

Explorer
Just remembered something I'd meant to say here, but was in a hurry back then and forgot...

That screenshot is showing data from the Victron BMV-700, which is a shunt-type amp counter battery meter. It's not showing data from a charge controller.



I didn't buy the bluetooth dongle for my charge controller. Still undecided if I want that or the LED meter. Leaning toward the meter. Only one data port on the charge controller so I don't think it's possible to use both at the same time unless there is some adapter I haven't seen yet.

No, I don't believe you're able to plug 2 items into the Victron charge controllers. They now have a 'Smart Solar' controller in addition to the 'Blue Solar' controller. The difference is that the Smart version has the bluetooth already built in leaving the port for a MPPT control display unit.

I'm digging back into this project and getting ready to pull the trigger on a few things. One of the last items to figure out is how to wire in a shunt with 2 sources.

What I'm looking at is...
Panel: 100w Renogy Eclipse panel with tilting brackets from AmSolar mounted to the cab of the truck
Controller: MPPT Victron Smart Solar 75/15 (Bluetooth connection to Victron Energy ap)
House battery will be mounted under the bed and will be a Duracell Deep Cycle AGM group 31 battery from Sams.
Charging from the truck will come from a Blue Sea ML-ACR
To monitor the overall health of the battery regardless of which source is charging I'll use a Victron MBV712 (which ties to the ap via Bluetooth as well) the display will be mounted in the dash.

---------------------------

For those who have wired in a shunt battery monitor fed by 2 sources, since the shunt is going in line with the negative side of the battery and nothing is allowed to bypass that line, would the ML-ACR relay from the vehicle be switched ground as well?
In other words one side of the shunt would be...
-the negative from the solar controller
-the negative from the starting battery via the ML-ACR
-negative lines for any loads
The other side of the shunt would be a single heavy wire directly to the house battery

That would leave the positive starter battery and positive solar controller being directly tied to the house battery positive?

I suspect the ML-ACR doesn't care whether it's switching the positive or negative lines --- the most important thing being that all negative lines run to that shunt.

I'll work on a diagram.
 

dwh

Tail-End Charlie
A shunt is not a switch. Everything is the same with or without the shunt. All the shunt does is add a place to easily connect an ammeter.
 

dwh

Tail-End Charlie
Oh...I see. Missed the part about the ACR in the neg line.

Why on Earth would you do something whacky like that?
 

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