Hey all. I'm the first to admit I know sweet FA about all this so I thought I'd ask here first.

I'm taking my B250 on a trip this summer and would really like to somehow wire a generator into it as I'll be using the TV etc a fair bit when parked up. Is this possible? Could this be done by having it connected to the battery in some way or would I have to have 2 seperate sets of wiring for each of the electrical things in there, one for the normal use off the battery and another set to go to the generator through something that would make it 12V? Or would it be best to have 2 batteries and a charger for it to run off the generator when I wasn't using it?

I know on caravans they van run of the battery or when plugged in to a power source, this was the kind of thing I was thinking but only if it wouldn't be a massive job.

Cheers

 

Assuming you bought a generator with 12v outputs, you can just run leads from there to the battery. If your generator doesn't have 12v outputs then just plug a battery charger in and then connect it to the battery.

 

If all you want to do is run a TV, then an inverter with under voltage protection would be the easiest. If you want to protect your primary battery from over discharge, then you are looking at a dual battery setup, with the box that segregates the alternator charge to the batteries. The box prevents the batteries from trying to equalize between the sets. This is bad if the batteries are different. You can always hook them up with jumper cables if you need to start from the other.

Then you hook your inverter to the second battery. If you go that route, Id suggest a marine battery for #2 since those handle full discharges better than a normal auto battery and also come in larger sizes for greater run time.

It isnt that hard to put a second battery behind the drivers seat in a box. Use a battery box because it will keep things off of the battery, and the battery off of things as well. I ran 6Gague though the firewall 3" below the spedometer. What wire you run depends on how much current you need to use and how long the wire needs to be to get where you need it.

The bigest issues are how big is your alternator current production wise(Amps), and how much of a load does the inverter need to power (Wattage). Most inverters are rated 80% efficeint or better. The better is more expensive.

Let us know what your other questions are.

 

Thanks for the replies, the first option is sounding the best so far, mostly because its the easiest!

Would there be any problems with over charging the battery if the generator was on for a long time whilst I was using the electrical things in the van? Got a 12V fridge, flat screen monitor and dvd/stereo with 4 6x9 speakers in it. Not sure how much power that would use in comparison to what the generator would kick out. Have found a nice looking 1100w generator which seems like the best option.

 

If you go the generator route, I would not connect it to the vehicle electrical at all. If you need to charge the car battery, I would do it with the generator and a conventional battery charger. There would be some loss of efficiency but would probably be more stable over the long run. Also I would work out a way for the generators' exhaust to not re-enter the van. Carbon Monoxide poisoning is not the way I'd want to go.

Lastly I've seen some of these "quiet run" generators be much louder than what most people would consider to be quiet. You may want to start the thing and see how loud it really is before making up your mind completely.

This part may be more than you need to know, but some may find it interesting, and it will help you figure out how much each thing you want to plug in will draw.

The way to figure the load is the same foe any device. Power (Watts) = Energy (Volts) * Current (amps). That will tell you its running load, It's starting load may be much more. There are two types of loads, Inductive and Resistive. Inductive is like a drill, vacuum, or other motor, Resistive is a coffee maker, lights or a TV. Some loads -- like a microwave -- are both. A load is a load only as long as it is on or plugged in depending on the type.

A microwave rated wattage can be confusing, so go by the back plate. Normally the stated wattage of a microwave is how much power it radiates into the food chamber, not how much power the whole unit uses to operate.

The above power formula can be solved for any unknown, so you have a 1100W of (rated) power from the generator equal to the Voltage (110V nominal) times the Current

1100w = 110v * A . . . . . . 1100w/110v = A . . . . . . A=10 Amps of current max.

I wouldn't try to run a large vacuum off of that generator! (why vacuums are advertised based on the power they waste I still don't understand - more isn't necessarily better.)

Incidentally, all a stand alone generator is, is a motor with an alternator, inverter, and regulator attached and a know rated output. Whereas the alternator on your car is rated on its max current output, not its idle current output which will be much less.