Inexpensive Battery Monitor -entry Level

[RoyBraddy]

MUSTANG65- My batteries are just now starting to drop off on performance on my OFF-ROAD POPUP TRAILER. These are three 85AH 12VDC Batteries in parallel giving me 255AHs of capacity. Four of these were originally installed in late 2008 and Ilost one battery to overcharging using a WFCO 8945 converter/charger. After that I switched to the PD9260C Converter/charger and the remaining three batteries are still performing today.

My other hobby is Ham Radio which I have consoles in both my Truck and my OFF-ROAD POPUP trailer. I am sharing the same HF SSB 80-10 Radio between the truck and the camper. Sometimes however I am just using my truck and this becomes a battery problem as I am constantly running down my truck start battery.

Game plan now is to install new external batteries in both the Truck Bed and the Trailer tongue area. When camping together I will add both systems together to give double battery capacity. I want to move the current 255AH battery setup to the house and setup there as well to run a Power Inverter and have backup battery power for my house ham radio setup.

My OFF-ROAD POPUP trailer already has a great battery monitor panel I built up using two 12VDC digital voltmeter meters and one 70A DC Current meter. I may move this panel to the house since it does not have a settable DC VOLTS alarm feature which is really a must have thing when camping off the power grid. Then both my Truck and my OFF-ROAD Trailer will use separate PZEM-051 Battery monitor meter.

I also am just now starting to think solar panels for the OFF-ROAD POPUP trailer roof area. I have enough room here for a two 120WATT Panels and one 240Watt panel. This will enhance my 2KW Generator operation recharging my depleted batteries each morning when allowed to run my generator here on the East side of the US. Once I get past the initial high current demands when the batteries are hit with 14.4VDC I can switch to solar panels and should get my banks back up to their 90% charge state before I need to start using them again for the next day/nigh of the batteries. I suspect we will be getting high sun here for 5-6 hours...

Been thinking about these changes here for a couple of years now and slowly adding parts and ideas when I can afford them.

I really wanted to find a couple of these 70A DC Current donut samplers but I only got one of these back in 2008 and then the company sold out and the price went from $40 to $800 dollars haha...


This is driving my DC Current meter in my current homemade battery monitor panel in my OFF-ROAD Popup trailer.


This is my battery panel mounted in my trailer...


Always playing with something...

Roy Ken

[Mustang65]

Originally Posted by RoyBraddy

MUSTANG65- I really wanted to find a couple of these 70A DC Current donut samplers but I only got one of these back in 2008 and then the company sold out and the price went from $40 to $800 dollars haha...

Can you use this with your current (no pun intended) setup? Not sure if you will need a burden resistor.

Don

[RoyBraddy]

MUSTANG65- Don... I have looked at those already. The hole is not big enough to slide in 4AWG cable. Some of my cables are also 2AWG size...

I think I read those hole size was .25 by .4 inches...

I also want something that uses 12VDC verses 5vdc like alot of these things use. Won't have to adapt down for that...

The Honeywell unit was perfect for my application. I haven't looked again for awhile maybe some of those are back for sale at a good price...

I like the hall effect sensors... Just slide a cable thru them and you are good to go. Don't have to worry about hot wires getting shorted out somewhere when using the SHUNT RESISTORS... It also works out better for me to use the positive side of the battery where all of my BLUE SEA Battery switches are located verses the ground side like all of the shunts like to use...

NOTE: I see DIGI-KEY is selling the Honeywell CSCA-A SERIES for 100A for around $38 but you would have to build up a cable to mate with their unit.. Thats not too bad actually...



Roy Ken

[Cdash]

Originally Posted by Mustang65

If you are interested in looking at the battery status in both charging or discharging modes, there is an easy fix. Wire the load/battery display connections that connect to the shunt to a DPDT (Double Throw-Double Pole) switch and manually switch it when you are charging or discharging. This will change the display from one mode to the other. You could mount the DPDT switch right next to where you mount the Digital Display.

Don

I just finished wiring mine up and installing. I liked the idea of seeing charging, so I installed the DPDT switch (on-off-on) as you suggested. I'm not getting anything beyond voltage when I have the switch flipped to the other pole. Actually, when I'm plugged into shore power, I get no data (not that it really matters, but I thought I would). When I unplug shore power, I see what seem like reasonable numbers. About 0.5 amp nothing else on draw, about 7.5 amp with furnace running and that's as far as I experimented so far.

I'm happy with the result, other than the fact that the switch didn't do much. Nice little meter for not much money. I installed by using an electrical plate and grinding down the screw nubs , followed by a coat of paint, then screwed to the woods panel in my battery compartment.

I'd be curious if anyone else got theirs to show charging??

[norty1]

That's a good McGiver for a mounting box. I'm still looking out for one to mount mine inside.

Too many small projects on hold now due to family sickness.

[RoyBraddy]

CDASH - I may have asked this before but how bright is the display in the dark. My meters turned out really bright and I had to install ON-OFF small toggle switches on them. Lit up my whole OFF-ROAD POPUP camper....

Roy Ken

[Mustang65]

Originally Posted by RoyBraddy

CDASH - I may have asked this before but how bright is the display in the dark. My meters turned out really bright and I had to install ON-OFF small toggle switches on them. Lit up my whole OFF-ROAD POPUP camper....

Roy Ken

Good Morning,
The display light can be turned on and off.
Don

[Mustang65]

Originally Posted by Cdash

I'd be curious if anyone else got theirs to show charging??

I will try to wire it in today with the switch... I just reversed the wires on my wife's scooter (used before her knee operation) and it displayed charging and discharging. I reset the display before reversing the wires.
Don

[5thGenTexan]

The last time I was able to make a trip in the trailer was 1998. Life got in the way. It sure was less complicated back then,

I used this to monitor the battery along with a cheap meter from Radio Shack.
OK, my chart wasn't even this detailed. My chart had 100% 75% 25% and dead.

[klassic]

I love this little guy. It fits on the cabinet rail perfectly.

[Subaru297]

I got mine in a couple weeks ago but I haven't had time to play with it yet. I have a TM2030 installed already but I was thinking of adding this to the solar side to see what the input voltages and current are.

What shunt did you use with yours? I think it is calibrated for a 100amp shunt isn't it? Mine shipped with a 50amp shunt though. I ordered a 100amp one as well though.

[klassic]

Yes it is a 100

[Levinehikeski]

You can come across that unit on eBay, too. I use a CTEK 40-149 CTX bluetooth battery monitor, works with android or apple products to give you a percentage left. Nice unit, hopefully app updates will allow you to see more info.

[klassic]

Originally Posted by Subaru297

I got mine in a couple weeks ago but I haven't had time to play with it yet. I have a TM2030 installed already but I was thinking of adding this to the solar side to see what the input voltages and current are.

What shunt did you use with yours? I think it is calibrated for a 100amp shunt isn't it? Mine shipped with a 50amp shunt though. I ordered a 100amp one as well though.

Subaru does the 2030 tell you everything the voltage moniter does?
I'm slowly creaping my way into solar. Still looking for a hot deal on a ts mppt45.
So my, slightly PITA, moniter install will be useless after I get the Morningstar moniter?

[Subaru297]

The 2030 tells me all the same information but only the voltage and current going into and out of the battery. It measures current both ways as well and keeps track of amp hours used and replaced. It tells you other things as well like how much excess solar power you have after your batteries are charged or if they aren't accepting all the amps being produced.

I want to install this just to see the voltage and amps coming directly from the panels to see how efficient they are as well as how efficient the charge controller is. So this shunt would be installed between the solar panels and the charge controller where the Trimetric is installed between the battery and everything else.

Hope that makes sense.

Cheers

[BuddyRay]

Cdash - your mounting solution made me look at a aluminum wall switch plate for a rocker type switch. The rectangular hole isn't large enough but can be enlarged with a nibbler or dremmel tool - and if I paint it flat black it should make a very hansom mounting even for inside the coach.
I would use a metal switch plate because the thickness is just perfect for the mounting tabs on the unit - a plastic switch plate is too think.
I use the plates for a rocker type switch because the screw holds are wider apart and are still usable after enlarging the hole for the meter.
I'll post photos if I get it to work.

[BuddyRay]

I went to HomeDepo today and picked up a couple of metal switch plates. I got 2 in case I messed one up. They were only .98c so . . .

Here are the photos of the mount:

Here's one of the white metal (paintable) plates next to my nibbler tool and scratch awl. I basically put the meter on the plate and scratched a line around the base of it.

Then I used the nibbler to eat away the metal back to the line. It took about 10 minutes but I was patient. I might have been able to use a sheet metal blade on my jig saw but that's hard to control. Radio Shack used to sell these nibblers to cut holes in project boxes - don't know if they still do.

Here's the plate post "nibble" - note the two cutouts on each end for the tabs - I just cut these back about 1/32 of an inch, it didn't take much. I then used a grinding wheel on my dremel tool to smooth out the edge - I probably didn't have to do this, it doesn't show under the edge of the meter, but I'm a type A

Test fit before painting. In these photos it looks like the flange around the meter covers part of the screw hole - but that's an artifact of the angle of the picture - in fact it just clears the screw hold perfectly.

Paint job - I used flat black - I think I'm going to repaint with gloss - the flat doesn't match the meter very well but it was all I had laying around the shop. You'll notice the 2 black pan head wood screws I'm going to use to mount this right under my control center. I'll put a photo of that up after I finish the install.

The advantage of using the plate is that the tabs on the meter "click" into the plate really solidly - then you can screw the plate to whatever you wish. It also means you don't have to be a precise in cutting a hole in the cabinet as the plate will cover a world of jagged cuts. The plate is an "oversized" outlet cover by the way. You might get away with a normal sized one but HomeDepo didn't have any in metal.

[norty1]

Nice solution! I have the meter but have not had the time to work out a mounting solution. I think I can make this one mine.

[klassic]

That's a great idea

[Mustang65]

Very nice job!!!!

Don