New 6V batteries, Boondocker and fuse q's

[CaCraig]

I'm moving the 12V flooded battery on my 71 Sovereign (rear bath) to the street side under the twin bed. The original battery was mounted in the rear compartment.

The original layout had a fuse on the negative battery wire going to the Univolt. From what I've been reading, I should move the fuse to the positive side. What amp fuse should I use?

The other question I have is about wiring the converter. Last year I ditched the Univolt and installed a 60amp Boondocker and new fuse panel. For the last year the electrical has been fine. I wired the 120V to the Boondocker, then to the fuse panel. Then I wired the battery + and - to the fuse panel. So when I'm on shore power electricity flows through the converter to the fuse panel. When I'm on battery, electricity goes right to the fuse panel. Why are people wiring their batteries to the converter?

Thanks

[AstroBruce]

Originally Posted by CaCraig

I'm moving the 12V flooded battery on my 71 Sovereign (rear bath) to the street side under the twin bed. The original battery was mounted in the rear compartment.

The original layout had a fuse on the negative battery wire going to the Univolt. From what I've been reading, I should move the fuse to the positive side. What amp fuse should I use?

The other question I have is about wiring the converter. Last year I ditched the Univolt and installed a 60amp Boondocker and new fuse panel. For the last year the electrical has been fine. I wired the 120V to the Boondocker, then to the fuse panel. Then I wired the battery + and - to the fuse panel. So when I'm on shore power electricity flows through the converter to the fuse panel. When I'm on battery, electricity goes right to the fuse panel. Why are people wiring their batteries to the converter?

Thanks

Put the same value fuse on the positive side.

Connecting the converter directly to the battery helps avoid voltage losses with longer wire runs.

Bruce

[lewster]

Originally Posted by CaCraig

I'm moving the 12V flooded battery on my 71 Sovereign (rear bath) to the street side under the twin bed. The original battery was mounted in the rear compartment.



The original layout had a fuse on the negative battery wire going to the Univolt. From what I've been reading, I should move the fuse to the positive side. What amp fuse should I use?



The other question I have is about wiring the converter. Last year I ditched the Univolt and installed a 60amp Boondocker and new fuse panel. For the last year the electrical has been fine. I wired the 120V to the Boondocker, then to the fuse panel. Then I wired the battery + and - to the fuse panel. So when I'm on shore power electricity flows through the converter to the fuse panel. When I'm on battery, electricity goes right to the fuse panel. Why are people wiring their batteries to the converter?



Thanks

Any fuse is positioned in the circuit as an over current device and as such, should be rated to the ampacity of the wire used for that circuit.

Example: if your cable is 10AWG, you would need a 30A fuse on that cable, which is the maximum rating for 10 AWG cable.

Consult the readily available ampacity tables for the rating for the wire in question. Remember that the purpose of any over current device is to protect the wire from potentially receiving an excess of current and burning or melting.


Lew Farber

[Morgan guy]

Make sure in your new battery placement that you have allowed for ventilation. Flooded batteries can release hydrogen which can be explosive.

[CaCraig]

Ooops. I meant to say I went from a 12V flooded Trojan to 2 6V Lifeline AGM batteries.

The original wire from the battery to the Univolt was 6 gauge with a 50amp fuse. Since I've now moved the batteries to under the street side twin I think I added about 1-2 feet in length so I think I'm still fine with a 50amp fuse. I'll put one on both the + and the - sides. Thanks for the replies.

[lewster]

Originally Posted by CaCraig

Ooops. I meant to say I went from a 12V flooded Trojan to 2 6V Lifeline AGM batteries.

The original wire from the battery to the Univolt was 6 gauge with a 50amp fuse. Since I've now moved the batteries to under the street side twin I think I added about 1-2 feet in length so I think I'm still fine with a 50amp fuse. I'll put one on both the + and the - sides. Thanks for the replies.

You only need one on the positive side since any over-current event will blow the fuse and interrupt the circuit. I would highly recommend the new MRBF fuses as they attach directly to the battery positive bolt and are extremely compact with a high amperage interrupt capacity (AIC) rating.

Since this is a series connection, I would definitely upgrade your series connection cable to a minimum of 2/0. This connection should be of the same size and ampacity as the internal bus bars inside the battery since you are essentially making one large 6-cell 12VDC battery from 2 6VDC 3-cell units with that series connection.

Also remember that you can position Lifelines in any orientation EXCEPT terminals down.

[CaCraig]

Thanks lewster. I ordered one of those MRBF fuse holders and a fuse.
I did use a 2 gauge wire to connect the 2 batteries together.

I have a solar question for you. I bought 2 Renogy 100W panels (AM Solar is out of stock or I would have gotten theirs) and the Trimetric and SC-2030 solar controller. I did get the adjustable mounts from AM Solar. Do you have any experience with this controller? The instructions says the fins can get hot. I wanted to mount it under the twin bed with the batteries but maybe there's not enough air circulation under there. The next place I thought I could mount it would be on the back wall of the double pantry. There probably isn't much circulation there either but there is more volume of air.

Thanks.

[lewster]

Originally Posted by CaCraig

Thanks lewster. I ordered one of those MRBF fuse holders and a fuse.
I did use a 2 gauge wire to connect the 2 batteries together.

I have a solar question for you. I bought 2 Renogy 100W panels (AM Solar is out of stock or I would have gotten theirs) and the Trimetric and SC-2030 solar controller. I did get the adjustable mounts from AM Solar. Do you have any experience with this controller? The instructions says the fins can get hot. I wanted to mount it under the twin bed with the batteries but maybe there's not enough air circulation under there. The next place I thought I could mount it would be on the back wall of the double pantry. There probably isn't much circulation there either but there is more volume of air.

Thanks.

Craig,

Sorry, but i never use the TriMetric products as all of my installations are either with Blue Sky MPPT controllers of Victron MPPT units and their respective battery monitor functions.

If it says it gets hot, I would be doubly sure that you have more than adequate ventilation where ever you will be mounting the solar controller.

[CaCraig]

Thanks. I'm going to call Bogart and ask them where I should put it.