I want to run my Webasto when I am parked, as well as my circulator pump and fans. I dont want to run it off batteries, so I am was thinking an Iota 55A power supply. That way I can plug into 110v and not mess with the batteries. Make sense? [55A will be plenty]
If so, what would be the easiest way to isolate the 2-8D's so they arent in the equation? Or....should I just hooked power supply to the batteries and go that route?
Your house 12 volt system should really be separate from your chassis 12 volt system. I would install some battery capacity in case you do lose your 110 volt feed. You can at least limp along for a bit. The 55 amp converter would work just fine for this.
No room for more batteries and I wouldnt if I had the room. I dont really have much of a 12v house setup. Just what I listed and a few lights. I have a generator for 110v if needed. Why should I separate things?
I assume the Iota 55 is a power converter. If so that will work just fine if 55 amps is enough and it will charge your batteries also.
Just make sure it has a three or four stage charger like the latest models. The older models are battery killers.
It does, but I dont want it to charge my batteries. My batteries wont need charging. I want it totally separate from them.
If you're certain you'll always have 110 volt power then you can get by without another battery.
I have a genset, if I dont. I wouldnt ever run it off just the batteries. Of course, I would make it that I could charge batteries if the need arose. I just prefer to not use the batteries for anything but starting and driving down the road and I surely dont want to get involved in a battery bank.
A battery and a converter can add a lot of utility to your vehicle, and, in fact, the modern inverter can do miracles. Just don't get me started on solar panels. ;)
I assume that you do not want to camp in places like National Parks. They not allow generators from 7pm to 7am (or something like that). Without a battery, you will be using flashlights to get around at night.
I suspect a lot of organized campgrounds that don't have electric won't allow generators at night. (I don't camp in organized campgrounds.) I know that the RV parking lot I work at once a year won't allow generators at night and has no power.
The Iota 55 is quite a good choice for a power supply, since it has a good voltage regulator and is intended for use as a power supply, in addition to being a good multi-stage battery charger. You can set it at a constant 13.6 volts regardless of current output, and I think it works fine without a battery. In this mode it is designed to offer a constant voltage for optimum use in an RV for lighting, powering up appliances, etc. I have a similar one (45 amp) in my truck camper, although I use a battery as well.
Brian
I don't like converters. They just create 12vdc and do nothing else. On my bus I have a 2,500 watt inverter that turns into a 130amp battery charger. If you don't want a lot of extra batteries, I would just simply use a couple of size 31 deep cycle batteries for your house use and keep them charged with the inverter/charger. It's automatic, and you don't have to worry about anything. In the likely event of a power outage, the inverter will kick on so fast, you won't loose microwave clock memory.
Deep cycle batteries for the lights and such is a good idea since you'll always have a standby and batteries will absorb spikes in voltage. Good Luck, TomC
This is a converter and a charger. Actually it is Webasto who suggested this. These are what they use on their benches to run their units.
I want to hook up my power supply like this drawing shows. If I do this, as the ground is shown, that will supply the bus with 12v, yet it wont apply charge to the batteries. Would that be correct, seeing I took the battery ground out of the equation?
Yes, the batteries will both be out of the circuit, neither supplying voltage to the bus or being charged, until the switch to ground in closed. The power supply will work, since it does have a path to ground.
Brian
It seems to me to be the simplest and most straight forward way to get power to everything without constantly charging and drawing batteries.
If I understand your diagram correctly, yes it will work the way you want it to, assuming the assorted devices you are trying to power are connected to ground via various places on the bus chassis, rather than directly to the negative cable / terminal of the battery.
I must admit I'm with everyone else though - I'd have a house battery. Keeping your start battery isolated is sensible (although actually charging it while on shore power is even more sensible), but the logic of not having a house battery escapes me. To me the benefits far outweigh the disadvantages - but then this hobby is all about 'doing it your own way'.
Jeremy
I understand what you are saying. First I have no room for more batteries nor the desire to make boxes and room. We get in this thing, drive to our venue. We turn a few lights on and the webasto when needed. We sleep, wake, sing and go to the next venue then come home. We have nothing else in there that requires power. Sure, if I was going camp in this thin or live, I might reconsider. All it is is a mode of travel and a bed.
I really don't want to leave the batteries in and draw and charge, right? In this case wouldn't it be best to use the batteries just for starting and running stuff going down the road?
Your start batteries should just be for that. However, I still think you would be better off installing at least one separate battery for the house. It won't take up all that much space. The way you describe your needs you certainly do not need a large bank, but a house battery will give you a lot more flexibility. It can even serve as a backup for your starts and generator. Anyway, nothing you do is final. You can always change or upgrade later on.
How would a house battery give me more flexibility than a 55A power supply does?. I carry a generator and a small gas powered battery charger already.
In your described situation, you don't need a battery at all. You only use the webasto, and maybe a few lights, when you are plugged into outside power, and the webasto happens to need 12vdc rather than 120vac. You're only using it to power up the webasto. If you had a battery, you'd have to worry about it, maintain it, store it, and you don't feel that the added benefit of being able to use the webasto and maybe a few 12v lights when not plugged into shore power is worth the fuss. I get it.
I see nothing wrong with the plan, the wiring diagram, or the choice of power supply. If you ever decide to add batteries, you can with complete ease. You can switch at either the positive side or the negative side of the battery to take them out of the circuit, little to choose between it.
Brian
Got it, glad it makes sense. Well it made "sense" to me, but that can be highly underrated.
A single Gp 31 battery will provide you with a backup in case you find you can't use your gen or it fails for some reason.
This battery is about the same size as some auto batteries and your converter will keep it fully charged.
This is a very inexpensive solution to a real pain in the neck of a problem down the line. Any bus electrical or mechanical system will fail at the worst time.
I've used my two Gp 31s more than once as starting backups when my alt failed. Would have been in a bind without them. I got rid of one of my two 8D starters and installed the two 31s in its place. One 8D is plenty for starting but the two 31s are my backup.