Battery Fuses

shadow75

Member
Aug 25, 2011
98
9
8
Sale, Victoria, Australia
G'day Everyone,

With our new Caravan now two weeks old, I thought it was time to have a look at what battery was actually fitted, and see what sort of job had been done.. Well, I didn't actually get to check because I ran into a few issues. (The Battery works fine - first trip away free camping was great - although only one night)

When I opened the Battery cover there were three fuses directly connected to the battery.. Firstly, there is no labeling of any sort, so no idea initially which one is for what.. Out of the 3 fuses, (all 30 Amp) two where blown..

By tracing the wires, and a good old multimeter, I finally found the following

#1 - Setec Connection for charging / battery use - 30 Amp Fuse Good
#2 - Anderson Plug Connection - Direct to Car Aux Battery (50Amp Breaker in Car) - 30 Amp Fuse Blown
#3 - Solar Wiring Provision (no Panels fitted yet)- 30 Amp Fuse Blown..

So.... for #2 the Anderson Plug, I'm guessing the charge rate from the Alternator could have been >30 Amps to the Batt, hence the fuse Blown. The wiring in the car is 6 B&S, although the wiring in the Caravan is only 6mm (ie 4.58mm2).

But.... for #3 the Solar connection was also blown, but has no connection.. I checked the box on the roof, and the connections had not been terminated, just cut, hence it is possible that these wires may have come in to contact with each other although unlikely. (now taped up to prevent any further issues until the solar panel project happens)

Is there any chance that Jayco has just put blown fuses in to start with? Seems a bit odd for both to be blown.
Has anyone else had experience with the blown fuses with the Anderson Plug or Solar Connections?
Could the 6mm cable actually take 50 Amp, or would this be too much for it?

Appreciate your thoughts,

Cheers,
Glenn
 

boots33

Well-Known Member
Jun 25, 2011
708
679
93
Maudsland Gold Coast Hinterland Qld
Hi Glenn
6mm auto cable is rated to handle up to 50A by most suppliers, the real issue is with how long the cable run is. Depending on where they have mounted your battery you could have 6m or more to get from there back to your anderson plug. This will cause voltage drop if any medium amount of power is drawn through it. Fortunately you have a 30A fuse fitted so that will be the limit applied to your cable. As far as the blown fuses are concerned I think you will find they were probably blown accidentally by the jayco installers at fit out. you have already taped up the solar leads so check that they have wired your anderson plug correctly and replace the fuses. Under normal circumstances the power being drawn from your vehicle will be quite low as your van battery will supply most of the power, so the 30A limit will not be an issue.
 
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shadow75

Member
Aug 25, 2011
98
9
8
Sale, Victoria, Australia
Thanks Boots :)

I've had a day of playing in the Caravan, and looking at the charge rates through the Anderson Plug. After discharging the battery for a couple of hours at ~15 amp hr, I plugged the car (running) Anderson Plug in. The highest I saw was around 16 Amp.

No blown fuses so far, but will wait and see.. In the mean time, I've ordered some 30A circuit breakers to replace the 30A fuses.. Hopefully will not be needed..

Thanks again :)