help with the basics: simple bus system

[Sluggo]

OK I am in the process of converting a 1999 Ford shuttle bus. I am planning on using it to haul my Jeep to offroad parks and general camping duties. My trips will be normally 2-3 days up to 1 week. I may have shore power and may not.

My plan

Bus has 2 batteries now but I think I need a house battery?
I need a converter but am lost on which and their capabilities?
I am a little lost on charging a house battery, I know a converter will do it when on shore power but what about on the road? does the bus charge it too?

I have a 4000w peak propane generator that will be mounted in the back

I want to run

Always

12 volt roof fan
LP furnace fan and thermostat
lighting (LED)

Rooftop Air Conditioner
phone and computer charging


When on shore power
Mini fridge (conventional for now)
coffee pot
toaster
Electric Skillet

Please help me plan a simple cost efficient system. I am pretty familiar with wiring but am lost on dual, triple systems, ground switch? isolator? Please help a dummy.

[Sluggo]

OK update

I am going to run a single 12v deep cell house battery. hooked to converter for shore power charging and hooked to existing batteries with a positive disconnect for bus charging versus shore power? sound right?

All bus 12v, lights, fan, furnace blower hooked to this battery.

AC power is still up in the air but it seems like regular fuse panel with standard wire seems normal?

I have read about ground nuetral issues but the generator or shore power should determine that correct?

[turf]

welcome to the forum!

looks like you got a good start on electrical. there are a lots of good resources around to help you out.

everyone's system is unique, so there are lots of right answers. you have the pieces down. you need to calculate you loads, battery bank size, charging times with the generator, and how long you want to go on a charge.

with a big enough battery bank, you could go 3 days. a single battery is probably too small for that.

my house battery bank is 4 batteries X 110 AH each for a total of 440 AH. i use about 220 AH a day, so it works out that when i'm off of shore power, camping, i need to run my generator 1-2 hours a day to replenish part of that. lead acid batteries charge slow, so on a generator its hard to get them back to full charge.

so if i start out day 1 at 100%, morning of day 2 i'm around 50% and need to run the gen. the gen recharges that to about 80% for day 2, back down to 45-50% when i wake up on day 3, i run the gen for 1-2 hours and i'm back at 80%, until i can plug back into shore.

i also cook when i use the gen charging, so eating and charging go together. maybe an hour in the morning , and another hour in the evening.

solar would be a more efficient way of keeping batteries charged. if you are all 12v, you should look into that.

size your need in amp hours and go from there.
here is an easy load calculator:
https://www.altestore.com/store/calc...ad_calculator/
good luck!

i just re-read your post and you said roof top AC. that won't work on battery, only gen time. fridge needs to be on 12v battery.

[coolbus]

I've got two AGM house batteries at around 60AH each, and use a smart isolator to charge them while the bus is running.

Link: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I really like that isolator, its rated for 140amps which is right around the max my alternator can spit out. I've found that when it turns on and my house batteries are very low, about 65 amps or so will come across it in my setup.

[PNW_Steve]

Originally Posted by coolbus

I've got two AGM house batteries at around 60AH each, and use a smart isolator to charge them while the bus is running.

Link: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I really like that isolator, its rated for 140amps which is right around the max my alternator can spit out. I've found that when it turns on and my house batteries are very low, about 65 amps or so will come across it in my setup.

That looks like a very kewl piece of gear. I have used the conventional battery isolators and the voltage drop (.6v-.8v) is enough to be problematic if you are trying to get a good charge on your house batteries from the coach charging system.

Thank you for sharing that.

S.