Dash mod to include Bank Monitor

[ncrr]

With all the talk about batteries and maintenance, and since I'm faced with the prospect of replacing my battery bank, it seems a good opportune time to have a better way of monitoring the bank itself along with the individual batteries within the bank. I saw post by robertk where he put individual DVM's for each battery, I thought was a great idea, especially if you are trying to isolate a poor performing battery within your bank.

Not wanting to devote that much space on the dash, I looked at two alternatives:

Option #1 - Leave the dash mounted 'bank' DVM where it is, and install a small panel in the battery compartment with the 7 DVM's (I'm moving to 42VDC with 7 6 volters). This would be a relatively easy solution, and just lifting the seat would expose the panel, or
Option #2 - Using the dash mounted DVM, install a rotary switch that would allow the that single DVM to be switched to display the total bank voltage, and also be able to show the voltage in each battery within the bank.

Clearly Option #1 is the simplest, and Option #2 more complex since it involves a handful of wires (8 pairs)going from the battery compartment to the dash, and a rotary switch. The estimated cost of either is shown:
Option 1, 7 small,DVM's and a about 25' of red/black pair wire, about $13 and
Option 2, 1 DVM (you may already have the dash DVM, and will not need another), 1 rotary switch, about 75' of red/black wire, About $25 (add about $5 if you need the DVM).

I chose Option #2, I elected to replace the DVM with one with larger numbers(old age sucks)and #2 offered the better solution since the values could be read right from the seat (old & lazy too huh).

Major items parts list:
uxcell KCZ 2 Pole 8 Throw 6mm Shaft Band Channel Rotary Switch Selector w Cap $9.47
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1


20ga 25' Red/Black Hookup Wire 12V DC $5.42 ea
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1


Waterproof Monitor DC 4.5-150V 12/24/36/48V Volt Battery Meter 0.56" LED Blue &9.99
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1


Additionally you might use some ty-wraps, crimp lugs and wire loom.

I first ran a cord thru the path I expected to take with the wire harness from the dash to the Batteries to get the length of the wiring harness. That came out to about 7 feet, and I added 12" just in case, and cut all the wires to length.

The rotary switch is a DP8T, and has two levels, one level for each of the poles with 9 switched terminals, one being the common or unswitched, and the rest 8 switched.. Both the positive and negative leads from each battery must be switched in order to get independent readings on the voltage at each battery. I chose the inner level for the negative leads, and the outer for the positives. Look closely at the outer level of the switch, in the centre there is a contact that rotates to each of the terminals, one terminal on the end is longer, touching the centre ring further in, and you do not connect any of the wire harness there, that is where we will connect the DVM.


This is the completed switch harness.


During the 'build' of the harness, the wire pairs were tagged with numbers that correspond to the rotary switch position. Wire #1 will go across the whole bank, so the full bank SoC can be seen, Wires #2 thru #8 will be connected across battery #1 thru #7, to individually monitor each battery.
The diagram;

(If not clear enough, yell, and I'll redraw it darker....)

I ran this harness through the square hole in the back of the dash compartment. I had not noted this path in the past, it offers better protection than other routes I've used earlier. I'll be moving some wires..... Since the loom I used is about 1" in diameter, I will leave a chase cord behind so I can pull additional wires thru this same route. The end of the loom comes up in the battery compartment under the passenger seat.

On the dash, the rorary switch is located in the panel below the switch, I still need to mark the positions "Bank", and "1" thru "7"


It took about a total of 5 hours. That includes making up the harness, getting it run, and hooked up.

[dundeebarnbuggy]

Is that rotary switch sealed from the environment when it is assembled? I can see issues with all those little wires connected to the corossive batt terminals and the contacts in the switch creating a false low reading, 5 or more years from now when an actual failing battery is likely happen.

[ncrr]

Originally Posted by dundeebarnbuggy

Is that rotary switch sealed from the environment when it is assembled?

dundeebarnbuggy,
Yes, it is encased in a plastic enclosure...... The area where the wires come out has been sealed up with silicone. I used a small round tupperware like box, with the back of the switch towards the cover (wires going thru the cover), and knob shaft coming thru the bottom (which attaches the switch to the dash). That way if the switch has to come out to check something, popping the cover off fully exposes the switch.

Guess I should add that tidbit to the writeup, pull the switch, and take a picture.

Thanks.....
Henri

[robertk]

Originally Posted by ncrr

dundeebarnbuggy,

Yes, it is encased in a plastic enclosure...... The area where the wires come out has been sealed up with silicone. I used a small round tupperware like box, with the back of the switch towards the cover (wires going thru the cover), and knob shaft coming thru the bottom (which attaches the switch to the dash). That way if the switch has to come out to check something, popping the cover off fully exposes the switch.



Guess I should add that tidbit to the writeup, pull the switch, and take a picture.



Thanks.....

Henri

Nice! I looked at doing something similar with a rotary switch but figured I could sacrifice the space under the cup holders and not miss it much- and it was a bit easier (but your way is much less expensive). I think mine cost around $80 with the mounts, DVMs, and 6 bank mini rocker switch panel. I have enjoyed using mine especially while charging to check on the voltages and can watch each battery at the same time.






2006 TXT series

[dundeebarnbuggy]

Originally Posted by ncrr

dundeebarnbuggy,
Yes, it is encased in a plastic enclosure...... The area where the wires come out has been sealed up with silicone. I used a small round tupperware like box, with the back of the switch towards the cover (wires going thru the cover), and knob shaft coming thru the bottom (which attaches the switch to the dash). That way if the switch has to come out to check something, popping the cover off fully exposes the switch.

Guess I should add that tidbit to the writeup, pull the switch, and take a picture.

Thanks.....
Henri

Good Man! I assume all your battery lugs are soldered and sealed too....

[ncrr]

Originally Posted by dundeebarnbuggy

Good Man! I assume all your battery lugs are soldered and sealed too....

dundeebarnbuggy,
You betchum Red Rider.... Soldered, shrink tube, and some awful grease that JohhnyB suggested to retard corrosion. I coated the battery hold-down rods & nuts too.
Henri

[ncrr]

Originally Posted by robertk

Nice! I looked at doing something similar with a rotary switch but figured I could sacrifice the space under the cup holders and not miss it much

I do like your setup, and I looked at that, and I also looked at that little space on the center right on a stock ez-go where the 8 or so holes are. I was thinking of stacking some 'bare' DVM's (no case) there. There is enough room, but SWMBO rejected the idea because of the emitted light. We do a lot of night rides, and we like looking at the sky, with all the stars and stuff.
Thanks for the idea!!!!

Henri

[robertk]

Originally Posted by ncrr

I do like your setup, and I looked at that, and I also looked at that little space on the center right on a stock ez-go where the 8 or so holes are. I was thinking of stacking some 'bare' DVM's (no case) there. There is enough room, but SWMBO rejected the idea because of the emitted light. We do a lot of night rides, and we like looking at the sky, with all the stars and stuff.

Thanks for the idea!!!!



Henri

7 batteries would have thrown a kink in either of my plans. I had thought on going with an 8 position rotary with the 12 o'clock position being all off and then cycle through batteries 1-6 with position 7 being pack voltage.

How do you turn yours off? Do you just leave it on the pack voltage position and then take the leads for pack voltage from the key switch?




2006 TXT series

[ncrr]

Originally Posted by robertk

7 batteries would have thrown a kink in either of my plans. I had thought on going with an 8 position rotary with the 12 o'clock position being all off and then cycle through batteries 1-6 with position 7 being pack voltage.

robertk, I did as you were thinking, and used an 8 position switch. Basically I'm wired closely as you have mentioned. The only difference is that position #1 goes to battery #1, position #2 goes to battery #2 and so on for the rest of the batteries. Position #8 being the bank voltage. I did not think of having an off position, might have bee a good thought, just a different switch. I felt the important part was to keep tabs on the bank itself.

Originally Posted by robertk

How do you turn yours off? Do you just leave it on the pack voltage position and then take the leads for pack voltage from the key switch?

There is no off, as I said above, that might have been a good thought. The wiring for the bank voltage is just another pair, running directly from the bank. That one I wanted to be a straight thru, to avoid any possible losses thru any cart wiring and it's connections.