Volt/amp meter

[Nutta]

I bought one of these http://www.radioande...al-shunt-2.html for my van so i can keep an eye on whats going on.

I have dual batteries and am guessing for this thing to work properly all wiring that comes off the batteries would need to go through this thing for the amps etc to show properly?

If so, there are about 8 - 10 fairly thick wires coming off the batteries, so I'd need to fit something to put the wires into one plug so i can run them through this, is that right? Or can i just hook it up to a battery direct?

Cheers

[cravenhaven]

i cant find any reference to documentation about it, so I guess you are correct in what you say. You'll have to gather all of your positives and all of your negatives into 2 bunches and connect them to the red and black wires on one side of the meter. The other side of the meter will connect to the positive and negative terminals of the battery.

[Ray!]

I think that the meter is primarily designed for such things as solar panels, where it would be very useful, but with only a max rating of 20A it may not be enough to handle the current typically sent to accessory batteries. My battery charger will deliver 25A to my campervan batteries and alternators will deliver considerably more.

Cheers

Ray

[mk tank]

As the unit only has a peak current rating of 30Amps, I would only put it in line with your fridge.

You can use the VOLT meter sense on the battery.

Current measurements are done by putting a shunt resistyor in line and measurering the currant

[Glort]

DO NOT WIRE YOUR BATTERY LEADS THROUGH THAT METER!!

I'm not exactly sure how you are intending to wire that meter from what you have written but just in case.... ^^^^^

As ray points out it is only 20A and a vehicle output will be far higher than that. If you wire the starter battery through it, the second you try to start the vechicle you will either blow the fuse in the thing of vapourise it if it has no protection.

Even on an isolated battery, you would be very lucky for the thing to handle all your accessories and luckier still if the thing wasn't overloaded once the engine was started and the thing was recharging. At only 20A, even below that rate that meter could cause resistance and drop the voltage or amp output.

For what you want, you need a meter with and external shunt capeable of handling much higher currents. You also need to look at the electrical system of the vehicle and only take off the wires coming off the terminals, not the battery leads themselves. You also need to make sure there are no other wires coming off the starter terminal as is sometimes done to make sute you get a proper reading.

I think you are really better off with just a volt meter. The amp input is less important than what voltage the battery is at. The amps will be regulated in charging and in discharge the battery level is more important than what the draw is on the battery.

You could be pulling 2 amps on a battery but if the thing is down to 11V, then you are in a place you don't want to be.

It would be much better to get a meter for automotive use.

If you have a power outlet at the rear of the vehicle, you could wire this meter in there to keep an eye on whats happening and it would do well in that application.

[Nutta]

Thanks guys, its only for the van so if i just throw it on the battery somewhere it will at least tell me the voltage?

Cheers

[Ray!]

If you have a line going out of the battery to plugs etc, then it should be quite safe to use it for both V and A by splicing into the outgoing cable, but it's not safe to install it into the incoming line from the vehicle.

Cheers

Ray

[Nutta]

No worries, I dont think The 12v electrics in the van would hit 30 amps, what would be the best way to get 10 wires into one wire of the volt meter?

cheers

[Ray!]

I used connector blocks available from Jaycar that are used by the doof doof crowd to power their amps. You can get these at various sizes that allow you to go from a large cable size down to smaller sizes as you split the power. The best thing is to group the cables, rather than try and bunch them all together. Mind you, I'm not sure that the cable size on your meter is ideal as the main outlet from the battery. I use much thicker cable which is then split down into smaller cable more resembling what your meter has as standard. That's why I think that meter is primarily designed for solar panels.

Cheers

Ray

[Nutta]

All the cables coming off the van battery are similar size to the meter by the looks of it, prolly 8 of them, so would those to the connector blocks be okay with the meter?

I suppose the fridge would draw the most power which runs off gas when we are parked up, so if i left the fridge out of the circuit that would hopefully minimise problems.

Actually i think youre right it was in the solar panel section, so i better be carefull with it.

Thanks.