Install Help on Digital Battery Meter

[Rainman4820]

I have a digital readout battery voltage meter I plan to use to monitor batteries SoC on a 1991 Marathon 36v. The meter has 1 black and 1 red wire. Can I just install black on last negative terminal and red to hot side of key switch? I have also read where these should be wired straight to the + and - terminals of the batteries although that would seem to ensure that the meter stays lit all the time which doesn't sound desirable.
Appreciate the assistance

[mgray70]

Straight to the terminals would be the most accurate. You can do like you said. Either way would be fine, it's not going to draw enough amps to hurt that battery pack if it stays on all the time.

[Sir Nuke]

Rainman......there are plenty of people that have done both ways that you mentioned, and both are correct way to do it, its really more of a preference. If you chose the method where its on all the time, as mgray70 mentioned, the tiny leds don't draw hardly any amps and won't hurt a thing.

[Rainman4820]

Great.... thanks mgray70 and Sir Nuke for taking time to respond. Its installed and ready to roll!

[JohnnieB]

In some drive systems, the keyswitch does not have voltage going to it unless the F/R is in either F or R, so the meter flickers off and then back on when you shift directions. Other that that, either way works fine.

As long as the control wiring to the keyswitch and the contacts of any switch that precedes it are in good electrical condition, the voltage at the keyswitch will be within a few millivolts of the voltage at the battery terminals and will give you the same reading on a DVM battery meter, which typically only resolve to 100mV.

The DVM battery meter I have is connected directly to the battery pack and with little exception, has been on 24/7 for 5 years and is still as readable and as accurate as it was when if installed it.

Personally, I find it comforting to glance at the meter whenever I walk by the cart and see the pack voltage is where it is supposed to be. If I had a need for the cart to be completely blacked out, I'd connect it to the keyswitch, but I don't have that need, so I connect it straight to the battery pack.

[Volt_Ampere]

Compared to the normal self discharge, the meter is a very small load so you can connect it directly to the battery system without switching it.

[mgray70]

Originally Posted by Volt_Ampere

Compared to the normal self discharge, the meter is a very small load so you can connect it directly to the battery system without switching it.

Correct!. They will self discharge more than the meter will draw probably.

[scottyb]

Diddo on the on for years outdoors test results. The meters are flawless.
I believe you need a 60 of these meters on to equal the pack self discharge rate