Overheating Engel Batt Box Charger

Thanks for your advice Frank.

I will look into the Merrit style plug next week.

I'm not 100% sure on how the Variable Voltage Alternator works.
From what I have heard they are a fuel saving feature??

I will run 8 gauge direct from the battery to the Batt Box through an isolator. It must draw massive power. It does draw 12v, boosts it to 24v which runs into the internal charger to charge a 12v Battery. Sounds like hard work....

This one even has Engel Stumped.

Thinking further about it Scott, 20 amps is right on the limit of a Merrit plug and socket. I'm thinking of the Narva 82108BL found here. They are rated at 20 amps. Don't even consider the 82106BL with its single earth terminal. Maybe go for a 50 amp Anderson. Not pretty, but bullet proof.

Somebody else may have a better suggestion, but at those current levels Andersons are a practical solution.

Cheers

Um yeh cigarett lighters where never designed as a power supply connector...they just got adapted.

The best ciggy socket I can fing is only rated at 15 amps..and that is generous.
The contact resiatance of ciggy plugs is very poor and unreliable.
I would not expact a ciggy plug to deliver more than about 5 to 7 amps on a continuous basis...even a good one.

Then there are the lower rated ones.
Look in your fuse box or woners manual.....lots of the "accessory sockets" that look like ciggy plugs in modern cars have 10 amp fuses on them..and that may service other things like the radio too.

As for the merit plugs...yeh well nice try but no cigar.....that are a better thing than a ciggy plug, but 20 amps on a merit plug.....not continuous no way.

The merit sockets I have here are all rated at 1amps max, the plugs well hell....one version I have come fitted with an 8 amp fuse.

If you are hooking a large 130 amp battery with a fairly low charging resistance to the main battery and charging system, what will limit the initial current flow will be the resistnace of the wires...and that current could be in the hundreds of amps if the wire is heavy, the main battery is fully charged and the aux battery is flat.


I mabe My visew on these battery boxes clear in the past.
They are a great marketing product, but they fall short in so many ways...ya far better off custom building.

cheers

sorry typo..merrit sockets rated at 15 amps max.

and version of plug comes with 8 amp fuse fitted.

cheers

Hot joint maybe?

Had a look at the Engel battery box and the DC - DC charger in it is meant to be only 6 amp output. Taking into account the voltage drop that occurs on the undersized wire of the average cig' lighter socket it still shouldn't have drawn more than 10 amps. If though there is a poor connection at the cig' lighter socket this will draw more current (amps) and cause heat, (blown fuse).
I would recommend that the cig' lighter socket be removed and replaced (ideally with a Merritt socket) and check that the wiring is OK. If it has been damaged the wire may create a fire hazard in the future and therefor need to be replaced.

Hope this advice helps.
Mal