Inverter Advice Please.

[PhilandMena]

I have just installed a Sterling 300W pure sine wave inverter in my motorhome and would welcome some advice on installation method.
I have connected red and black cable directly to + & - terminal clips on one of my leisure batteries and all seems to be well. However, on my control panel leisure battery states 13.7 V yet digital display on inverter states 12.5. I don't get that as I'm on hook up on the drive.
Also, on the back of the Inverter there is a wing nut for an earth cable. Is it essential I earth the inverter, this may be a problem as the leisure batteries are in a locker and I can't see any means of getting a cable to the Chassis.
Thanks in Advance,
Philip

 

[Reallyretired]

Most inverters are not earthed, indeed I'm not sure what you could earth it to in a vehicle as the vehicle chassis is not earthed, merely a ground return and just connected to the battery -ve.

If you get two different voltage readings from the same battery then it looks like one of them is wrong, however if the inverter is displaying 12.5v with the inverter on and no load then it may be that your connecting wires are too thin or too long. If the inverter is on and under load then it would be expected that there would be a voltage drop.

 

[PhilandMena]

Most inverters are not earthed, indeed I'm not sure what you could earth it to in a vehicle as the vehicle chassis is not earthed, merely a ground return and just connected to the battery -ve.

If you get two different voltage readings from the same battery then it looks like one of them is wrong, however if the inverter is displaying 12.5v with the inverter on and no load then it may be that your connecting wires are too thin or too long. If the inverter is on and under load then it would be expected that there would be a voltage drop.

Thank you for that. The Inverter (Sterling) came with the wires already factory fitted, all I needed to do was to attache to battery. There is no load on the inverter so I'm at a bit of a loss. Instructions are nonexistent !

 

[Reallyretired]

In that case it looks like one of the voltmeters is reading wrongly, and if the battery is on charge on ehu then it looks like its the one on the inverter thats wrong.

 

[PhilandMena]

In that case it looks like one of the voltmeters is reading wrongly, and if the battery is on charge on ehu then it looks like its the one on the inverter thats wrong.

I think your right! The leisure battery readout has always been spot on. Sargent systems on modern (2011) motorhome.
I'll have a chat with the supplier tomorrow.
Thanks for your input.

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[peterc10]

Phil

The 13.7V is probably right if you are plugged into the mains. That is the normal trickle charge voltage from memory.

I assume you and Mena are now safely home from your travels

Peter

 

[PhilandMena]

Phil

The 13.7V is probably right if you are plugged into the mains. That is the normal trickle charge voltage from memory.

I assume you and Mena are now safely home from your travels

Peter

Yes Peter and thanks, a great Journey.