430 hp 70
'19 144 Gas Passenger - Carlsbad
I have a '19 144 gas passenger w/out the factory aux battery and have been researching the heck out of wiring the last few weeks. I've searched and read everything that I could find, but I'm still left with some questions.
Here's the plan -
Remove rearmost seat and build side cabinets over the wheel well and under the windows. Add a single aux agm battery behind the lt rear tire inside the new cabinet (vent through new hole in floor) . This will feed a fuse block to power a small 10a water/washdown pump with 17gal tank, 20a air compressor, all the stock, but rewired rear passenger usb ports and the added usb and 12v ports on the cabinets. Power ports will have constant power. I'm building a roof rack and may add flood lights to it as well.
Wiring-
Fab a little jumper inside the 150/1 (pic below) that's attached to the battery and add a 150 amp fuse. Run 2 awg wire from the starter battery to drivers seat base and connect to a si-acr. Run 2awg from acr to new battery. Neg of battery to a tie down anchor point now unusable due to cabinets. 4awg (i have a bunch of extra) from battery to new fuse block.
Questions-
What is the best path for the 2awg? There is no path through the side wall since it's solid between the two windows. I'd rather not drill through this solid point, I'd rather not go underneath the van and I don't want to go over the window if it's not necessary. There is a gap a little over 3/8 between the flooring and wall. Any reason not to lay the cable in that void? It runs front to back, is covered visually by panels and doesn't have sharp edges.
My fuse block has a spot for grounds and I plan to run all back to here. Would it matter if I connect this bus bar to the battery negative or to the same battery ground point on the anchor? I read it's best not to connect grounds directly to battery neg. Something about ground loops. I don't understand how connecting it all to the same body ground is any better than bat neg.
Is 2awg enough? It's what the Mercedes pdf calls for when adding a battery under the hood. But I'm guessing that's a <8' run. I'm at 12-14' if I can run in the channel. It will be closer to 25' if I have to go over the window. Blue seas calculator says 2awg is enough for 150a and 3% at 15' and 5% at 25'. I will never come close to 150a draw, but I still can't find max charging amps. If I undersize with proper fusing, is the only downside a slower charge?
Mercedes states no more than an additional 40a on the charging circuit. What is the additional charging amps the alternator would need to supply? Battery will be costco/interstate 95 ah agm. Do I need a limiter? The factory aux battery setup doesn't appear to have one.
There will be more questions and thanks in advance for any help.
Here's the plan -
Remove rearmost seat and build side cabinets over the wheel well and under the windows. Add a single aux agm battery behind the lt rear tire inside the new cabinet (vent through new hole in floor) . This will feed a fuse block to power a small 10a water/washdown pump with 17gal tank, 20a air compressor, all the stock, but rewired rear passenger usb ports and the added usb and 12v ports on the cabinets. Power ports will have constant power. I'm building a roof rack and may add flood lights to it as well.
Wiring-
Fab a little jumper inside the 150/1 (pic below) that's attached to the battery and add a 150 amp fuse. Run 2 awg wire from the starter battery to drivers seat base and connect to a si-acr. Run 2awg from acr to new battery. Neg of battery to a tie down anchor point now unusable due to cabinets. 4awg (i have a bunch of extra) from battery to new fuse block.
Questions-
What is the best path for the 2awg? There is no path through the side wall since it's solid between the two windows. I'd rather not drill through this solid point, I'd rather not go underneath the van and I don't want to go over the window if it's not necessary. There is a gap a little over 3/8 between the flooring and wall. Any reason not to lay the cable in that void? It runs front to back, is covered visually by panels and doesn't have sharp edges.
My fuse block has a spot for grounds and I plan to run all back to here. Would it matter if I connect this bus bar to the battery negative or to the same battery ground point on the anchor? I read it's best not to connect grounds directly to battery neg. Something about ground loops. I don't understand how connecting it all to the same body ground is any better than bat neg.
Is 2awg enough? It's what the Mercedes pdf calls for when adding a battery under the hood. But I'm guessing that's a <8' run. I'm at 12-14' if I can run in the channel. It will be closer to 25' if I have to go over the window. Blue seas calculator says 2awg is enough for 150a and 3% at 15' and 5% at 25'. I will never come close to 150a draw, but I still can't find max charging amps. If I undersize with proper fusing, is the only downside a slower charge?
Mercedes states no more than an additional 40a on the charging circuit. What is the additional charging amps the alternator would need to supply? Battery will be costco/interstate 95 ah agm. Do I need a limiter? The factory aux battery setup doesn't appear to have one.
There will be more questions and thanks in advance for any help.
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