Electric System - Converter/Inverter Specs

[Celeste]

Hi,

I'm in the middle of restoring my 13' 1977 Scamp. A friend is helping me to completely redo all of the electric. (This was really necessary, as it came to me without any running lights, etc. I had to put temporary towing lights on it to get it home.)

We have removed the old Progressive Dynamic electric thingy-ma-jiggy, the thing which makes it possible to go back and forth from 120V to 12V. I don't know whether it is a converter or an inverter. The label is missing from its front. I would really like to reuse it if I can, so I'm hoping someone here can help me out. I want to reuse it in order to avoid cutting a new hold somewhere, and in order to save money.

I guess what we really need is to identify the thing and get some specs for it.

Thanks for whatever help you all can offer!

Celeste

[Celeste]

Oh, and I should have said that what I want out of an electric system in the end is to be able to run a few small things (some LED lights, maybe charge a laptop), maybe a small fan, but nothing bigger than that. I won't have a microwave or a tv or anything like that drawing juice. And I would like to be able to be off the grid as much as possible, meaning not depending on plugging in at a campground. And I plan on putting in a solar system to charge the battery asap.

[Dennis Clinton]

Got one just a little bigger. It converts 120vAC to 12vDC, does not have a battery charger. I don't think it converts DC to AC. They are not very powerful. Once I changed interior lights to LED, it does fine(before, turned a light on, and the radio faded out then back in). Good luck

Oh, and the loose wires in the back:
2 are 12v circuits
1 is ground
1 is 12v to battery.

I had to plug mine in to figure out which was which.

[Perry J]

If you aren't going to need 110V I would lose it and just run the lights off the battery.
You can allways install a charge line from the TV to charge the battery.
For about $250.00 you could install a 50w solar array and be totally independent.
John

[Joe MacDonald]

email one of your pictures to Progressive dynamics, they are still in business, and they may be able to ive you some advice or a diagram for the converter, I had a quick look on their site, but don't see that particular model.
With the switch on the side you had the option of running from the transformer when plugged in, and off the battery when not, with an off position to prevent battery drain. This unit would not charge your batteries, or change 12 volt to 110

[MCDenny]

It sounds like you could get by with just a 12 volt system if you got laptop and cell phone chargers that plug in to a car cigarette lighter.

A pair of 6v golf cart batteries would give lots of capacity, a largish (10 - 20 amp?) charger would let you use shore power when available to recharge the batteries when necessary.

You would not need an inverter (changes 12v DC to 120v AC) or a converter (changes 120v AC to 12v DC). Your old thingy is a converter.

The best way to do this project is to start with an electrical budget (watts, not dollars). Make a list of each electrical device, how many watts it consumes and how many hours per day it will operate. Watts is amps times volts. You can do this in amps too if everything is 12 volts. If you have solar and want to estimate its energy contribution add this to the list as a negative number. Each device on your list will use X amp-hours. Add up the amp hours used in a day. Multiply that number by the number of days you want to go without recharging. Now double the number to get the battery capacity you need.

Let's say you will need 20 amp hours per day and want go without charging for a week. 20 x 7 = 140 a-h. You would need 280 a-h of battery capacity for best battery life. If you got AGM batteries (less maintenance, can be discharged deeper, cost more) you could do the math with a 1.5 multiplier instead of 2. In that case you would need 210 a-h.

PS: Even with all 12v stuff, it would be good to wire in a couple of 120v AC outlets for when you are plugged in to shore power.