Inexpensive Battery Monitor -entry Level

[northwindone]

I ordered a 120W suitcase solar kit this week as well as one of these monitors. For now I'm hoping I can put the monitor on the back of the solar panel next to the controller (which only has LEDs). I was planning on connecting it to the battery and shunt with quick connectors and running exterior grade telephone line to the panel bundled with the charger cables.

Anyone see a problem with this for a temporary setup? Eventually I will take the hinges and handle off the suitcase kit and mount it on the roof as I made sure this kit has real frames on the panels. For this summer though I'm too busy during the week to do a full solar install.

[BuddyRay]

Originally Posted by Mustang65

You do not need SOLAR for this product.

A lot of the members are interested in monitoring their battery performance (or lack of), but do not want to invest a lot of money and time into an expensive system. So enter a product that I just found on AMAZON (of course) and it will meet your basic battery monitoring needs for only $17.98.

The order comes with an EASY TO READ DISPLAY (yes you can turn it on/off) and a 100Amp shunt resistor. All you add is the wire (telephone quad wire, or Cat5) between the display/battery/shunt. You will also need to install the shunt resistor between the battery and the frame connections.

' ' ' '

Don

So if anyone is still reading this thread, I have a question I'd like input on.
Most of this thread talks about installing the Shunt Resistor right at the battery.
Would it work if it was installed right behind the electrical fuse panel?
I'm planning to install a 120v power management/surge unit back there so I was looking around. I can cut the large wire coming from the battery there and install the resistor and it will make it much easier to run the wiring to put the display where I want it.
I know there are some draws that don't run through the panel - but they are all things that are used while towing (like the breakaway switch) or during setup (like the levelup system). I think everything else comes through the panel.
So what are your thoughts:
1) will I get an accurate voltage level there to determine battery condition?
2) will I get accurate power usage (amps draw) while camping?
Any other issues - for example, does the shut resistor get hot?

[DanNJanice]

Originally Posted by BuddyRay

So if anyone is still reading this thread, I have a question I'd like input on.
Most of this thread talks about installing the Shunt Resistor right at the battery.
Would it work if it was installed right behind the electrical fuse panel?
I'm planning to install a 120v power management/surge unit back there so I was looking around. I can cut the large wire coming from the battery there and install the resistor and it will make it much easier to run the wiring to put the display where I want it.
I know there are some draws that don't run through the panel - but they are all things that are used while towing (like the breakaway switch) or during setup (like the levelup system). I think everything else comes through the panel.
So what are your thoughts:
1) will I get an accurate voltage level there to determine battery condition?
2) will I get accurate power usage (amps draw) while camping?
Any other issues - for example, does the shut resistor get hot?

I think what you are suggesting would work OK, as long as you are not too much of a perfectionist.
1) There will be some voltage drop from the run between the battery and the panel. But in reality, the large voltage drop will only show up if you have a high current draw...and if you have a high current draw measuring battery state of charge does not work well anyway. To get accurate SOC measurements you need a low (ideally 0) current draw or for that matter charge for a few hours.
2) Since you are already aware that some things may not route all the way back to the panel you should be fine. Current will measure the same anywhere in a series circuit. Ideally you want to measure all current flowing out of, and into the battery, that is why it is often easier to locate the shunt next to the battery.

[Mustang65]

After thinking about this for a while, I do not see any thing wrong with wiring it by the charge controller. As you mentioned there would be some voltage loss, but it will be minimal.. amps will be amps so no issue there.. The main point is that you will have a much better idea as to how your battery(s) are doing.

Don

[northwindone]

Got mine wired up so I can easily hook it up while using my suitcase solar kit. I put the meter in a project box along with a switch to switch between monitoring charge or discharge. It is hooked up with a quick connector, the other side of which is in the battery box, so it can easily be put away when not needed. The box will then just be attached with velcro to the back of the panel along with the charge controller. It looks nice enough that it will probably be put inside permanently with the new charge controller when I switch to a roof mounted system this winter. Just need to add labels to the switch, left for charge and right for discharge.

[chuckcarson99]

Thanks all for the good information here.

All has gone well, using info from various threads. Using in a Jayco 12C Popup, where I have a history of draining my battery at the wrong time!

Bought the Bayite Model PZEM-051 Meter and a nice lighted switch, Philmore 30-16535.

I have one externally mounted 24 series battery. I mounted the shunt in the battery box, then ran two sets of 2 wire to one of my a cabinet near my door so I can see while popup collapsed and in car charging mode.

Two open questions.

1 - DPDT switch - can't figure out how to to light when in either on position, then not when off. Lugs 7 (the 7th lug not used) and 3 (already used) indicated as the lamp lugs.

2 - How to not display meter reading when switch in off position - now as long as the meter is wired in to the battery, displays voltage even when switch in the off position (no current).

[Mustang65]

Originally Posted by chuckcarson99

.

Two open questions.

1 - DPDT switch - can't figure out how to to light when in either on position, then not when off. Lugs 7 (the 7th lug not used) and 3 (already used) indicated as the lamp lugs.

2 - How to not display meter reading when switch in off position - now as long as the meter is wired in to the battery, displays voltage even when switch in the off position (no current).

Chuck

WELCOME TO JOF!!!

The members here are GREAT!!! There is a lot of GREAT information to be found here.
Don

Well I see you found some good information already!

The PZEM-051 model only has 4 connectors, 2 for the Shunt and 2 for Pos/Neg battery supply. Not sure as to which lugs you are talking about.

If you want to totally turn off the meter in an easy way, install a small on/off toggle switch on the Positive wire that would cut the power to the Display.

Don

[chuckcarson99]

Hi Don,

Thanks for the nice welcome.

Sorry as I think my question was not clear. The reference to the lugs was for the lighted DPDT ON/OFF/ON switch. The directional flow seems to work fine, but I assumed when in the OFF position the meter would not read anything and the back light would be off.

Also when in either ON position, I was hoping to have the switch light working. The lamp circuit is between lugs 3 (pos) and 7 (neg), but I am not sure how to wire it in.

Not sure if you can help, but thanks anyways.

Chuck

[azrvr]

Originally Posted by RoyBraddy

Thanks klassic... Found it on the AMAZON page now...



Will get my order in for a couple of them... Got two projects this season to upgrade my OFF-ROAD Battery setup one in the OFF-ROAD POPUP Trailer and the other in the Bed of my truck.

I'm not all that liking for the SHUNT types but I am never going to find one of those DONUT typs anywhere cheap like the one I have like now... The DONUT type you just run the BATTERY CABLE thru the hole and it is all connected up... No hot wires running anywhere..

thanks again - didn't want to order the wrong one and the description does not list the model number - didn't think about looking on the pictures...

Roy Ken

Hi,
Just got two of these and installed them in our tt. The directions looked simple but maybe not because they don't seem to be working correctly. I used one shunt and reversed the wiring for the second meter.

What happens is on the one connected as per the instructions measures voltage but no current when not on shore power (just the battery connected). Even with the lights turned on.

But when I connect to shore power and flip the main breaker on then I get current. Around 3.40 amps with no lights on. When I turn the lights on it's around 6.30 amps. Does that seem high? The second meter only shows voltage even when on shore power.

Maybe I connected the shunt wrong? What I did is disconnect the ground coming in to the control panel and connected that to one end of the shunt. I used a new wire (8 gauge) to connect to the other end of the shunt and then back to the control panel where I removed the original ground.

Both meters had around 12.30 volts on just battery and around 13.30 when shore power is connected.

I thought that connecting the shunt at the control panel would be an easier project than running wires from the battery to the cabinet where I want to have the meters. It's a brand new trailer and I'm not sure what would be the best way to run new wires from the battery back to inside the trailer without tearing it apart.

Any advice?

[Mustang65]

Originally Posted by azrvr

I thought that connecting the shunt at the control panel would be an easier project than running wires from the battery to the cabinet where I want to have the meters. It's a brand new trailer and I'm not sure what would be the best way to run new wires from the battery back to inside the trailer without tearing it apart.

Any advice?

You need to have the shunt wired between the negative battery terminal and the frame. You then run the smaller gauge wire from there to where ever you want to mount the display. There are to many variables that will affect the output of the meter when it is mounted by the TT's charge controller.
I believe you will find an option to select the shunt you have 50 or 100 amp, which will alter the display readings.

Don

[azrvr]

Thanks Don.
I guess the good news is that I didn't fry anything. I'll try to follow the wires from the battery into the trailer to run the ground wires from the shunt to the meters. But I'm betting that I will have to remove some screws from the belly cover and route it through there and then drill a hole up inside the cabinet (without hitting any water pipe!). Maybe I will be moving the location of the meters into the pass-through storage area.

[Mustang65]

I did some measuring... found a Jayco predrilled hole behind the TT's charge controller (had wires going through floor), measured where it was on the floor with a reference point. I then went under the TT and did the measurements under there. Then I cut a small X in the under belly. I took an old piece of 8 gauge solid copper wire (a straightened old metal coat hanger would probably work also) and poked it through the hole and after a few tries, I did get it through the insulation and out the belly pan. Taped the wires to it and pulled it through the holes. I also attached a length of waxed string to it so in the future, should I need to pull any more wires through, I will have a fish ready to use

Good luck

Don

[azrvr]

Thank you Don!

I will check that out this weekend. That darn work stuff really cuts into my spare time. I did take a few vacation days this week and we are taking the new tt out to a local campground for the first time. Woo-hoo!

Thanks again.

Mike

[Fratzba]

FYI, I bought two of these meters. I just used one of the shunts, and wired one of the meters normally, and the other one I reversed the wires on the shunt.

So, now I have both charge and discharge meters, that show cumulative charge AND discharge over time.



-Fratz

[Mustang65]

Nice going Fratz.

Another successful hookup. 100th of a volt is pretty darn close for inexpensive monitors. I had to take the label maker and mark one IN and the other OUT... just to keep my brain straight.

Don

[azrvr]

Originally Posted by Mustang65

Nice going Fratz.

Another successful hookup. 100th of a volt is pretty darn close for inexpensive monitors. I had to take the label maker and mark one IN and the other OUT... just to keep my brain straight.

Don

And yet another great idea. I was wondering how I would remember which is which.

[Mustang65]

Is that IW telephone wire? Amazing the uses it gets. Blue,Orange,Green,Brown,Slate.....
Don

Originally Posted by Fratzba

FYI, I bought two of these meters. I just used one of the shunts, and wired one of the meters normally, and the other one I reversed the wires on the shunt.

So, now I have both charge and discharge meters, that show cumulative charge AND discharge over time.



-Fratz

[klassic]

Not that the 2way switch was a bad idea.. but for the 9 dollars these cost, having two set up like this is a better idea.

[Mustang65]

I started out with the 2 way switch when I mounted the single one on the designer board with the MoringStar Remote MPPT monitor. I since added 2 to my battery control center in the front compartment. Always changing things.

Don

[klassic]

I just received my Morningstar moniter and emc-1 Ethernet converter.
altestore.com was the lowest price I found on the net and they were having a 10% off sale on in stock solar goodies.
Now I can finally see what my controller is actually doing.