Wiring query

[andymb]

Running a 240v fridge in the bongo which pulls 75w, obviously this runs when on a hook up.
I want to run it off of the leisure battery through an inverter for when were on days out. I've got a 500w inverter to take care of the initial zap which works fine when connected via the clamps to the battery terminals. But my plan was to run it off of a 12v cigarette socket (off of the leisure battery) and for some reason it won't work (alarms saying the battery is low) any ideas why? I assumed that a 12v feed off of the battery would be the same as connecting direct to the terminals. If I can it would save me wiring from the bonnet to the boot.
Any advice

[g8dhe]

The max. current a socket is rated for is only 10 Amps which translates to 120Watts, with the efficiency of the inverter (<90%) and the current surge when the motor in the fridge starts you will be requiring a lot more than can be supplied by the socket and wiring. At 75 Watts average running (about 6 Amps) and say a 90AmpHour leisure battery then you will only get about about 10-15 hours running from the battery until it is totally flat - its normal to only run a L/B down to about half capacity if you want it to last which is even less about 7-8 hours running.

[GreenBongo]

You may find that the wiring to the inverter isn't substantial enough so you are getting a fair sized voltage drop, hence the alarm.

[andymb]

Ah that makes sense, will probably only need the fridge for the 3-4 hours we park up at the beach so will have to run a cable off of the LB. what cable would you suggest?

[blobber]

Personally, I wouldn't bother with all that faffing about for 3-4 hrs use. I'd put a frozen coolpack in a couple of hours before going to bring the temp. down, and then swap it with a fresh one when stocking up. Should stay cool long enough.

[andymb]

Know what your saying blobber but sort of sold the bongo to the wife as a kitchen on wheels.

[g8dhe]

Mount the inverter as close as possible to the battery, and then run the mains to the fridge there are less losses that way.

[winchman]

Is it a compressor or absorption fridge?
Compressors are noisy absorption is silent.
I have a Dometic DS200 fridge, its 65w and totally silent, they run fine from a 150w inverter so I would have thought a 500w would be too big and just cause you more losses?