Inverter help needed

[Pudsey Bear]

Eh? I thought the whole point was to check it on the inverter.

It is Barry, but I can't do that without the engine running, I don't have enough solar/battery to do it statically.

This is a 4 week shake down essentially, one to see if having a scooter makes life better for us both as Liz is limited to what I can do, then the feasibility of physically getting it in and out of the van, and how best to keep it topped up, I might find that a scooter is a good thing, but maybe not this one so all very suck it and see, I also don't have unlimited funds and the cost so far is really more than I can spare but needs must, with fuel etc all going up even keeping the van at all is in question, especially if it's just sat on the drive.

 

[Geek]

If the inverter claims to be 86% efficient and the charger puts out 48 watts (probably at similar efficiency) that means the input power is about (48 /0.86) /0.86 watts, which is about 69 watts. Assume an input voltage at the inverter of 12 volts, that's a current of around 5.5 amps.
The dash sockets were designed to power a cigarette lighter, providing a slightly higher current than that, but only for a few seconds.
A 12v dash socket is easily able to provide that current, but not really good for that current for a long time. A battery will take hours to recharge
It will probably overheat, and it might get hot enough to loosen the spring that holds the plug in. If that happens, things get worse and worse, possibly even melting or catching fire.
I would get it hard wired, with a suitable switch. Far more convenient, more reliable and safer.

 

[Pudsey Bear]

If the inverter claims to be 86% efficient and the charger puts out 48 watts (probably at similar efficiency) that means the input power is about (48 /0.86) /0.86 watts, which is about 69 watts. Assume an input voltage at the inverter of 12 volts, that's a current of around 5.5 amps.
The dash sockets were designed to power a cigarette lighter, providing a slightly higher current than that, but only for a few seconds.
A 12v dash socket is easily able to provide that current, but not really good for that current for a long time. A battery will take hours to recharge
It will probably overheat, and it might get hot enough to loosen the spring that holds the plug in. If that happens, things get worse and worse, possibly even melting or catching fire.
I would get it hard wired, with a suitable switch. Far more convenient, more reliable and safer.

This is my Ducato 12v dash socket, I assume this was designed with more than a lighter in mind, but I'm not sure what that means in relation to using it for the inverter.

 

[merl]

Thanks, cheap enough to get one, but wouldn't going up to 4 amps mean a bigger inverter?

A 4A charger would be well within your inverter spec and around 2/3 of the rated spec of the dash power socket. BUT that assumes there's no gremlins in your set up. Throw a towel or some clothes over the inverter or charger or have dirty or loose (and hence high resistance) contacts in any part of the wiring and the maths don't mean jack 5hit. Like geek said hard wiring would eliminate the possibility of problems caused by a bad connection at that 180w power outlet.
I suppose it all depends on if you're risk averse you are . As long as the socket was dash mounted I'd personally make sure the plug and socket was nice and clean and free of tarnish and the plug felt nice, tight and positive and then get the swmbo to have a feel of the plug occasionally (oooh er missus) and take it from there. If the power socket is in the rear of the van then I probably would hard wire it instead.
Merl

 

[Pudsey Bear]

I'm going to link to the other thread as I'm fielding two or more replies and it's confusing the issue for me.

https://motorhomebuilder.com/threads/inverter-help-needed.67422/page-2#post-880488

So I'll copy your comments above over and answer there.

 

[Geek]

This is my Ducato 12v dash socket, I assume this was designed with more than a lighter in mind, but I'm not sure what that means in relation to using it for the inverter.

Yes, those sockets usually have a 15A fuse. Fine for a high current over a short time. Run it at 10A for half an hour, then take the plug out and feel the temperature of the tip.

 

[Pudsey Bear]

Thank you Mr Geek.

I moved the subject over to Motorhomebuilder.com as there were more replies on there, and it was getting complicated following different threads on different forums.