Battery Meter Install Help

[Farrier]

Bought a meter/switch plate from CartsUnlimted for a 36v PDS cart. I'm only reading 19.2volts. With fluke meter, it reads 38.5volts.

I tried different wiring fashions; battery meter always illuminated w/ key off, and only illuminated with key on. I get 19.2 +/- volts either configuration.

[kgsc]

Sounds like it is reading half voltage. Not sure how. Might just be a bad meter.

[Tom47]

Not sure what Scotty sells, but some voltmeters are calibrated for 36 and some for 48 volts, while most are auto-ranging for multiple voltages.

Try connecting it to your car battery and see what it reads. If it reads around 6 or 7 volts, it is a bad meter like KGSC mentioned.

[Farrier]

^^^Didn't think about that, good idea

[JohnnieB]

Where are you attaching the battery meter leads?

If you are attaching the positive meter lead at the keyswitch, the voltage is passing through at least 3 set of switch contacts before it gets to the keyswitch, plus 6 sets of plug/jack pins and 3 trips through the controller.

Also, the meter will shut off unless the F/R switch is in F or R.

The DVM battery meter I bought for Scotty was attached to the battery pack's main +&- terminals and has been on 24/7 for 10 years next month except for a battery replacement and during repairs when pack is disconnected. No noticeable deterioration in readability.

Here's a drawing of a PDS showing voltage paths through controller and external switches.

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BTW: If you are only getting 19.2V at the keyswitch, you need to do some electrical connection cleaning. It ought to be same as pack voltage, except when F/R is in R, the it'll be one diode drop less.

[Farrier]

^^^ So I should run leads from the meter directly to the battery pack instead of through the on/off switch? I'd prefer to have the battery meter only activate when the keyed on/off switch is used.

What trips me out is that my Fluke reads 38+/- volts but the meter that I'm trying to wire in reads 19+/- volts at the same 2 points.

[Tom47]

Originally Posted by Farrier

^^^ So I should run leads from the meter directly to the battery pack instead of through the on/off switch? I'd prefer to have the battery meter only activate when the keyed on/off switch is used.

What trips me out is that my Fluke reads 38+/- volts but the meter that I'm trying to wire in reads 19+/- volts at the same 2 points.

Yes, as JohnnyB said, this is the best way to hook it up. Mine is on 24-7 and it is nice to be able to view it from a distance periodically even during charging.

I do have mine hooked up after the run/tow switch, which is normally always on unless working on the cart.

Does the meter read 19 volts when hooked directly to the batteries? If so, it's defective.

[JohnnieB]

Originally Posted by Farrier

^^^
1. So I should run leads from the meter directly to the battery pack instead of through the on/off switch? I'd prefer to have the battery meter only activate when the keyed on/off switch is used.

2. What trips me out is that my Fluke reads 38+/- volts but the meter that I'm trying to wire in reads 19+/- volts at the same 2 points.

1. The voltage at the keyswitch is several steps removed from the battery pack voltage, so the voltage might be different. However, to each their own preferences and if you are aware of the potential voltage errors, you ought to be fine.

2. If the battery meter reads different then the Fluke meter, one of them is wrong. Question is which one is wrong.

Many handheld DVMs read high when their internal battery is weak, so replace the battery(s) in the Fluke and try again.

Also, use the Fluke to measure the voltage at the battery meter's input terminals to eliminate any wiring issues.