All the volt meters and amp meters should read the same. Make sure you have
all the loads on the shunt on the load side, not the battery side.
The battery volt meter source can come off at the battery side of the shunt.
Make sure that the volt meter wires are kept separate from the amp meter
shunt sensor wires. I have seen where the volt meter and amp meter share
one of the wires.
There is a certain size sensor wires that should be use for the length of
circuit that is use. Different size wires, will cause different readings
between one meter at the end of a circuit and another one at the beginning
of a circuit.
Be sure you install fuses on both lines of the volt and amp meter coming off
a battery pack. You could have over 1000 amp potential on these sensor
wires. I fuse mine instrument leads with Bussman 1 amp limitron fuses.
Check for any wire connections that may have a increase of resistance. A
spade terminal that is sandwich between two stainless steel washers will act
like a resistor.
One EV person made a mistake by connecting there DC-DC converter off the
battery side which would not show the addition battery ampere. I have any
of my other DC loads coming off the main battery shunt, but I also have
smaller shunts for each load, so I know what each load is pulling off the
main battery pack.
Roland
----- Original Message -----
From: "Hunter Cook" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Thursday, November 01, 2007 10:35 AM
Subject: [EVDL] Voltmeter discrepency
> Hi again,
>
> Just one more question... The voltmeter inside the vehicle consistently
> reads below the one on the battery charger. The charger was claiming
> 163v just now, but in the truck it only says 155. Is this typical? Which
> one should I be going off of to decide when I've reached finishing
> voltage?
>
> Thanks
>
> Hunter.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
all the loads on the shunt on the load side, not the battery side.
The battery volt meter source can come off at the battery side of the shunt.
Make sure that the volt meter wires are kept separate from the amp meter
shunt sensor wires. I have seen where the volt meter and amp meter share
one of the wires.
There is a certain size sensor wires that should be use for the length of
circuit that is use. Different size wires, will cause different readings
between one meter at the end of a circuit and another one at the beginning
of a circuit.
Be sure you install fuses on both lines of the volt and amp meter coming off
a battery pack. You could have over 1000 amp potential on these sensor
wires. I fuse mine instrument leads with Bussman 1 amp limitron fuses.
Check for any wire connections that may have a increase of resistance. A
spade terminal that is sandwich between two stainless steel washers will act
like a resistor.
One EV person made a mistake by connecting there DC-DC converter off the
battery side which would not show the addition battery ampere. I have any
of my other DC loads coming off the main battery shunt, but I also have
smaller shunts for each load, so I know what each load is pulling off the
main battery pack.
Roland
----- Original Message -----
From: "Hunter Cook" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Thursday, November 01, 2007 10:35 AM
Subject: [EVDL] Voltmeter discrepency
> Hi again,
>
> Just one more question... The voltmeter inside the vehicle consistently
> reads below the one on the battery charger. The charger was claiming
> 163v just now, but in the truck it only says 155. Is this typical? Which
> one should I be going off of to decide when I've reached finishing
> voltage?
>
> Thanks
>
> Hunter.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
