TheSamba.com :: View topic - How do I use 120V/1200 watt appliances in '67 Westy?

Sat Nov 18, 2006 11:48 am

I'm planning to use a 2nd battery (deep cell) to run my lights and stereo, and an inverter so I can have 120V power to plug into. Ideally I'd like to run my automatic espresso machine in the bus which is a 120V/1200 watt device.

Have any of you set up your bus to run high watt appliances effectively and if so what's your set up?

Thanks.

Sat Nov 18, 2006 4:28 pm

stephenmullens wrote: I'm planning to use a 2nd battery (deep cell) to run my lights and stereo, and an inverter so I can have 120V power to plug into. Ideally I'd like to run my automatic espresso machine in the bus which is a 120V/1200 watt device.

Have any of you set up your bus to run high watt appliances effectively and if so what's your set up?

Thanks. Be sure to purchase an inverter with a maximum rating no less than the total of your appliance(s.) If you know the amperage rating of your appliance but do not know the wattage, you can calculate the wattage with the formula: Volts x Amps = Watts. An example: A 120V appliance that runs at 10 amps will consume 1200 watts. You need to add about 15% to that, because the inverter itself will consume a bit of power. 15% more than 1200 watts is 1380 watts. To run three such appliances at the same time, you would need an inverter rated for 4140 watts or more, so a 5000 watt inverter would be a good choice.

After determining the size of inverter needed, you need to determine the size of battery (or batteries) required for the running time you want. The storage capacity of batteries is measured in "amp hours" (abbreviated "AH".) The definition of "amp hour" is the ability to provide 1 amp of power for 1 hour. To convert from total watts of load to AH, first use the formula Watts ÷ Volts = Amps. That will tell you the continuous amperage rating of your load. Then multiply that times the number of hours you want to run, and you have the required "amp hours" required from your batteries.

Looking at the example above, you'll see that an espresso machine requires about 1200 watts of power (at 120 volts.) So we first multiply 1200 watts x 1.15 (to add 15% for the consumption of the inverter) and get 1380 watts. Dividing 1380 watts by 120 volts = 11.5 amps of constant load. A nice Optima deep cycle battery like the model Yellow Top S 5,5 is rated 75 AH (amp hours) @ 12 volts. Because the inverter will be converting the battery's 12V current to 120V (which is greater by a factor of 10), we divide the battery's 75AH rating by that same factor of 10, and the result is that the S5,5 battery has a rating of 7.5AH @ 120V. So you'll need at least two of those

Some prety big ass power we are talking about. Could cost you up to $500 for a cup o coffee

Sat Nov 18, 2006 5:26 pm

Bursch wrote: stephenmullens wrote: I'm planning to use a 2nd battery (deep cell) to run my lights and stereo, and an inverter so I can have 120V power to plug into. Ideally I'd like to run my automatic espresso machine in the bus which is a 120V/1200 watt device.

Have any of you set up your bus to run high watt appliances effectively and if so what's your set up?

Thanks. Be sure to purchase an inverter with a maximum rating no less than the total of your appliance(s.) If you know the amperage rating of your appliance but do not know the wattage, you can calculate the wattage with the formula: Volts x Amps = Watts. An example: A 120V appliance that runs at 10 amps will consume 1200 watts. You need to add about 15% to that, because the inverter itself will consume a bit of power. 15% more than 1200 watts is 1380 watts. To run three such appliances at the same time, you would need an inverter rated for 4140 watts or more, so a 5000 watt inverter would be a good choice.

After determining the size of inverter needed, you need to determine the size of battery (or batteries) required for the running time you want. The storage capacity of batteries is measured in "amp hours" (abbreviated "AH".) The definition of "amp hour" is the ability to provide 1 amp of power for 1 hour. To convert from total watts of load to AH, first use the formula Watts ÷ Volts = Amps. That will tell you the continuous amperage rating of your load. Then multiply that times the number of hours you want to run, and you have the required "amp hours" required from your batteries.

Looking at the example above, you'll see that an espresso machine requires about 1200 watts of power (at 120 volts.) So we first multiply 1200 watts x 1.15 (to add 15% for the consumption of the inverter) and get 1380 watts. Dividing 1380 watts by 120 volts = 11.5 amps of constant load. A nice Optima deep cycle battery like the model Yellow Top S 5,5 is rated 75 AH (amp hours) @ 12 volts. Because the inverter will be converting the battery's 12V current to 120V (which is greater by a factor of 10), we divide the battery's 75AH rating by that same factor of 10, and the result is that the S5,5 battery has a rating of 7.5AH @ 120V. So you'll need at least two of those

Some prety big ass power we are talking about. Could cost you up to $500 for a cup o coffee

That's exactly the information I needed. Thank you for taking the time to provide the educational primer.

Now I'm going to have to rethink my priorities!

Sat Nov 18, 2006 6:35 pm

I thought about that for my Westy. Then I decided that it would not be roughing it. 8)

Sat Nov 18, 2006 8:36 pm

Looks like you're going to have to go for one of these:

(stovetop espresso maker)
and one of these:

(Coleman camping stove)

Sat Nov 18, 2006 9:46 pm

Type2meister wrote: Looks like you're going to have to go for one of these:

(stovetop espresso maker)
and one of these:

(Coleman camping stove)

LOL...that's not roughing it...my stove still uses coleman fuel and I have to hand pump the tank to build pressure...that propane stuff is for wussies :-)

Sat Nov 18, 2006 10:01 pm

stephenmullens wrote: Type2meister wrote: Looks like you're going to have to go for one of these:

(stovetop espresso maker)
and one of these:

(Coleman camping stove)

LOL...that's not roughing it...my stove still uses coleman fuel and I have to hand pump the tank to build pressure...that propane stuff is for wussies :-)

Umm Stephen that one pictured has a manual pump on it. :wink:

Sat Nov 18, 2006 10:25 pm

Ehem, uh, duh, I knew that :)

Sun Nov 19, 2006 1:15 am

Better not choose a machine like this:

better off with somthing like this?:

I am going to put an espresso machine in my bus, as thats the business I am in - espresso machines. Although I plan on mobile vending so I will plug in when I get to my desired location. I do believe I would like to run a laptop and epresso machine *and grinder*. Maybe a blender and a refridgerator. Of course I wont be using the short bus for that.

mike

check this out - same thing but air cooled would be nice

Sun Nov 19, 2006 5:20 pm

I was hoping to take our automatic espresso machine we use at home on the bus trips. It's small and light weight and uses coffee pods...very tidy and the coffee is really good:

Sun Nov 19, 2006 6:14 pm

The LBB will have a coffee truck out at BBB11. 8)

No cowboy coffee for us !!!

Although water boiled on the fire then into the french press is purdy good.

Mon Nov 20, 2006 12:16 am

Chemex and a small backpacking stove . . . good joe and easy to clean up.

Mon Nov 20, 2006 11:24 am

The setup on our 67 Westy uses a deep cycle (yellow top) optima with an inverter. The inverter is intended to keep very small AC appliances going and to provide continuous power to the icebox, which we converted to a mini-fridge by installing a thermoelectric unit and fan on top of the icebox compartment behind the little drawer. We cannot run high-current appliances unless we are in a campground hooked up to line current, or if the engine is running. They just place too much draw on the battery, and I did not want to have an auxiliary battery inside the bus.
HOWEVER, when the bus is connected to campground (line) voltage, the inverter is taken out of the circuit by a 120V DPST relay and the optima receives a charge as well. Then you can pull fifteen amps.

Replaced the stock generator/voltage reg with a "super 75" alternator and a battery isolator. Everything is hidden except the alternator and the second battery.

Mon Nov 20, 2006 5:27 pm

My Westy is a far cry from the POS 61 Sundial I owned.

Sun Sep 28, 2008 1:37 pm

Major Woody wrote: The setup on our 67 Westy uses a deep cycle (yellow top) optima with an inverter. The inverter is intended to keep very small AC appliances going and to provide continuous power to the icebox, which we converted to a mini-fridge by installing a thermoelectric unit and fan on top of the icebox compartment behind the little drawer. We cannot run high-current appliances unless we are in a campground hooked up to line current, or if the engine is running. They just place too much draw on the battery, and I did not want to have an auxiliary battery inside the bus.
HOWEVER, when the bus is connected to campground (line) voltage, the inverter is taken out of the circuit by a 120V DPST relay and the optima receives a charge as well. Then you can pull fifteen amps.

Replaced the stock generator/voltage reg with a "super 75" alternator and a battery isolator. Everything is hidden except the alternator and the second battery.

Back from the dead! :lol:
Woody, the DPST relay sounds like a good way to go from alternator to shore power but I have one question.
Are you worried about over-gassing your batteries when hooked up to shore power?
How do you cut off the power when they the batteries are at full charge?

Sun Sep 28, 2008 3:17 pm

The batteries are hooked to a 60 amp Intelli-Power unit (far left in photo below) that charges the auxiliary battery only, through the battery isolator (far right).

There is an Iota automatic transfer switch (second from right--basically a very fancy, high-current DPDT relay that automatically cuts off the inverter when the bus is hooked up to shore power).

The inverter (yellow box in center--700W continuous/1200W surge) is turned on and off manually, as one might not want it running during campouts without hookups. I would rather have the second battery available for the gas heater, the interior lights, and the fridge. When camping without hookups for an extended period, one would also opt for using a block of ice in the fridge and turning that off as well.

During the winter months, the bus can be left plugged in all the time and the Intelli-Power unit will monitor the status of the auxuilary battery and charge/condition it as needed.

There is no need to do anything with the main battery, because the only load on it when the bus is not running is the alarm.

The little gizmos mounted on the extreme right are the accessory fusebox and the control relay for the gas heater.

For those of you on "hack alert", I only drilled one hole in the floor of the bus for all of this.

Tue Sep 30, 2008 6:46 am

Very nice Woody! 8)
Will be doing something kind of similar at some point.
I should be getting my 2,000 watt inverter sometime this week.

For the overcharging, I already have an "intelligent" battery conditioner (trickle charger) hooked up to the bus to keep the starting battery charged.
I think I'll just bring it with me and hook it up, positive to the alternator output and negative at the battery ground. That way it should charge up both batteries, but not overcharge (theoretically).

Wed Oct 01, 2008 8:19 am

Major Woody wrote: For those of you on "hack alert", I only drilled one hole in the floor of the bus for all of this.

I like it.

Wed Oct 01, 2008 8:28 am

whats the best way to run dual batteries in a bus? My sons bus, the paddywagen has tons of electrical shit in it and Id like to install a second battery for it.

Id like to run his stereo system,airride compressor,and fog lights off the second battery.

also, how would I do it so that those things are only pulling power from just the second battery?

I plan on the second battery going in the drivers side of the engine compartment.

Wed Oct 01, 2008 9:22 am

my65vert wrote: whats the best way to run dual batteries in a bus? My sons bus, the paddywagen has tons of electrical shit in it and Id like to install a second battery for it.

Id like to run his stereo system,airride compressor,and fog lights off the second battery.

also, how would I do it so that those things are only pulling power from just the second battery?

I plan on the second battery going in the drivers side of the engine compartment.

You need a battery isolator rated for the size of your alternator. The instructions for wiring it come with the isolator.

You will then need to add a secondary fuse block powered off the second battery. If you locate the fuse box inside the bus somewhere, you will want to add a main fuse, circuit breaker or fusible link as close to the battery as you can, before the wire to the fusebox passes through any sheetmetal or gets near anything else that can damage it. I use a Sure Power isolator; they are made right near my home. Here is a link to a document that will teach you all you need to know about isolators, how they work, and how to size the isolator and the wiring to and from it to match the output of your alternator.

http://www.surepower.com/pdf/ebr_int.pdf

You can get these isolators used on ebay for cheap.

Mounting a second battery on the left rear corner of the bus is uncomplicated. You can modify the mounting brackets to bolt-on, or you can weld them in. If you plan on using the second battery with the car off for any length of time, you will want a deep cycle gel battery, like a yellow top optima or a Deka Intimidator. I have the Intimidator, mainly because it matches the performance of the Optima but it looks just like a regular square battery. I got a set of stock '67 mounts (thanks BarryL!), welded in the blind nut for the clamp and welded threaded studs to the "back side" mount, and bolted that through the tray with wing nuts. You don't see it. The Deka mounts exactly like the stock battery does. It doesn't interfere with the gas heater or with the spare tire well, but I did have to modify the taillight terminals slightly as space is snug with that large of a battery back there.

A little fuse block from Radio Shack is not going to handle the current that a big stereo will pull. It would be best to mount the aux fusebox and isolator inside the bus. For that reason, it would make sense to run one large wire off the battery terminal to a main fuse, then inside the bus to the #2 post on the isolator. You can then use this post to attach the other heavy conductors feeding the amplifier, airride compressors etc. If you have several other smaller loads, then add a fusebox. If not, then maybe an inline fuseholder is all you need.

Remember, the fuse must be sized large enough not to fry when it is at its maximum load, but no larger than the amperage that the smallest unfused downstream wire can handle.