pnishr
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Hey all. I've committed the cardinal sin... converted to 12v. AND I LOVE IT!! I did it the appropriate way with the Roscommon instructions. So, now I am getting read to re-install the driver's side alternator, and run a second battery bank (2 more optima yellow tops in parallel). I'll be running a 2500w inverter off of that. I've already got the cables and appropriate 250A fuse from the batteries to the inverter. SO, here is my question:
From what i understand, fuse selection is primarily a function of cable guage selection. You want the fuse to blow instead of cables to overheat/burn. Cable guage selection is generally a function of amps and distance it will be travelling.
In the roscommon instructions, they suggest using 8ga wire, with a 50A fuse in line to the second set of batteries. I'll be running the batteries in the back of the M1009. So, based on all the charts I've found online, I'm being very safe by choosing 4ga cable. As to the fuse size... shouldn't I want to use as large a fuse (within a very conservative margin) as possible, in order to charge those batteries faster? And given my 4ga cable, wouldn't a 70amp fuse still be quite safe (given a 125-150a rating on 4ga cable over 15ft), but allow more current? This is the one place I feel like straying from the Roscommon instructions. If I'm beefing up the cables, I should be safe in increasing the amperage for the fuse. Also, looking at one of these for said fuse. Resettable Circuit Breaker Cooper Bussmann
Any and all help is appreciated. I know everybody castigates the 12v'ers. But, I did it because it just makes more sense for my needs/wants of the truck. And since this is really more of GENERAL electrical/safety question, it shouldn't matter.
Oh, also, electrical stuff is not my forte, so try to keep answers as layman-y as possible. I've worked my way through issues from wiring diagrams on more than a couple of vehicles now, and I do own a good multimeter, but... well, most of what I know is self-taught on the topic, so go easy on my ignorance.
Please let me know if this post is more appropriate in another forum area.
From what i understand, fuse selection is primarily a function of cable guage selection. You want the fuse to blow instead of cables to overheat/burn. Cable guage selection is generally a function of amps and distance it will be travelling.
In the roscommon instructions, they suggest using 8ga wire, with a 50A fuse in line to the second set of batteries. I'll be running the batteries in the back of the M1009. So, based on all the charts I've found online, I'm being very safe by choosing 4ga cable. As to the fuse size... shouldn't I want to use as large a fuse (within a very conservative margin) as possible, in order to charge those batteries faster? And given my 4ga cable, wouldn't a 70amp fuse still be quite safe (given a 125-150a rating on 4ga cable over 15ft), but allow more current? This is the one place I feel like straying from the Roscommon instructions. If I'm beefing up the cables, I should be safe in increasing the amperage for the fuse. Also, looking at one of these for said fuse. Resettable Circuit Breaker Cooper Bussmann
Any and all help is appreciated. I know everybody castigates the 12v'ers. But, I did it because it just makes more sense for my needs/wants of the truck. And since this is really more of GENERAL electrical/safety question, it shouldn't matter.
Oh, also, electrical stuff is not my forte, so try to keep answers as layman-y as possible. I've worked my way through issues from wiring diagrams on more than a couple of vehicles now, and I do own a good multimeter, but... well, most of what I know is self-taught on the topic, so go easy on my ignorance.
Please let me know if this post is more appropriate in another forum area.
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