Solenoid relay size?? please help!

[evy]

Hi everyone,

Just trying to size the solenoid relay I need to add to my van's alternator in the engine bay to charge my house batteries as I'm driving.

How do I figure out how many amps is enough?

As of now I'm looking at a Continuous duty (golf cart type) solenoid with constant 150amp capacity and 300amp peak.

Here's a drawing (work in progress) of my DC setup :

[Scalf77]

Evy,
This recent thread, discusses sizing and different ACR's. The sizing would generally be true even if you went with a continuous duty solenoid. Again there are pluses and minuses to the continuous duty solenoid.

http://www.sportsmobileforum.com/for...d-19238-3.html

-greg

[winmag4582001]

This has been working perfect for me.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

The dual house battery setup I have has never drawn over 38 amp coming off almost dead status. I fused each of the batteries charge lines with a 50 amp. If they are pulling more than that on a charge, there's a problem.

[evy]

Originally Posted by Scalf77

Evy,
This recent thread, discusses sizing and different ACR's. The sizing would generally be true even if you went with a continuous duty solenoid. Again there are pluses and minuses to the continuous duty solenoid.

http://www.sportsmobileforum.com/for...d-19238-3.html

-greg

Thanks for the info Greg.

That leads me to another question I had, I looked at some videos on youtube and some poeple don't run a neutral wire all the way back to the van's battery (they ground it right next to the house battery), but some do (like in your drawing). I'm guessing that's the best way to go?

Also I've got a deal on some 4awg wiring (40$ for 100feet)
I was thinking of getting that and buying a wire crimper and some copper terminals.
I could use it for all the wiring around the house batteries (linking the two 6v batteries together/linking the house battery to the van's/inverter/battery grounding/supply busbar/etc...) Is 4awg ok or should I go bigger?

[winmag4582001]

How much electrical understanding do you have?
Is this going to be something you use full time or just on long weekends?
The demand on the system will dictate what you need to do and spend. If this is something you are going to use for having auxiliary power for short periods of time, say a three day weekend, or if you're going to be running a fridge along with other items 365 days a year while living in the van, will determine to what level you need to build.
I just used my system for four days while traveling around Telluride. Used it for my electric cooler, electric blanket, charging laptops, ect. Worked perfectly.
From the vehicle battery- to the VSR- to the house batteries, I'm running 4ga CCA wire to charge. Between the house batteries-to the inverter I use 4awg OFC. On all the lines "using" power I would suggest a minimum of 4awg OFC. It can carry power/amps without over heating. The reason I used 4ga CCA for the direct charge line is because the charge from the vehicle battery/alt to the house batteries is low amp. For the ground I used 4ga CCA, again, because of the very short distance to the chassis where the ground is and the fact I'm only using a 1500watt inverter.
I tested the system by running my vacuum cleaner along with the girlfriends hair dryer for over thirty minutes. Drawing an average of 1800watts for an extended period of time, the main power wires never exceeded 110 degrees. Acceptable for the amount of time and energy I was quickly using.

[evy]

Originally Posted by winmag4582001

How much electrical understanding do you have?
Is this going to be something you use full time or just on long weekends?
The demand on the system will dictate what you need to do and spend. If this is something you are going to use for having auxiliary power for short periods of time, say a three day weekend, or if you're going to be running a fridge along with other items 365 days a year while living in the van, will determine to what level you need to build.
I just used my system for four days while traveling around Telluride. Used it for my electric cooler, electric blanket, charging laptops, ect. Worked perfectly.
From the vehicle battery- to the VSR- to the house batteries, I'm running 4ga CCA wire to charge. Between the house batteries-to the inverter I use 4awg OFC. On all the lines "using" power I would suggest a minimum of 4awg OFC. It can carry power/amps without over heating. The reason I used 4ga CCA for the direct charge line is because the charge from the vehicle battery/alt to the house batteries is low amp. For the ground I used 4ga CCA, again, because of the very short distance to the chassis where the ground is and the fact I'm only using a 1500watt inverter.
I tested the system by running my vacuum cleaner along with the girlfriends hair dryer for over thirty minutes. Drawing an average of 1800watts for an extended period of time, the main power wires never exceeded 110 degrees. Acceptable for the amount of time and energy I was quickly using.

This is my first build, it's all new to me.
I'm learning slowly but surely, but don't worry, I'm no cowboy, I can plan everything in advance, run the wiring for the lights and other circuits but all the big gauge wiring, around the batteries/inverter/charger/converter/switch box etc... I don't have the confidence to do that and turn on the switch, I hope to find someone who has done this before and has the experience to point and tell me what to do and guide me before opening the kill switch.
I bought 100feet of 4awg wiring today, now I need a crimper and some terminals.

I won't live in this thing, I will use it for roadtrips here and there (I'm thinking 1 or 2 weeks min)
But I won't be boondocking the whole time, I'll be hooked up in camping sites at least 50% of the time? I'm looking for a 2100watts generator and probably be adding a 250watts solar panel with mppt controller.

I have a 1600W inverter, 3 way fridge, no dryer, no coffee, no AC, I will be running fantastic fan, LED lights, my laptop with the inverter...

I don't have the biggest budget, that's why I was looking at a solenoid relay to start things off (15$ on amazon).
After a while if I need to upgrade the 4awg wiring won't change, I can just change the solenoid for a VSR or something else right?

[winmag4582001]

Question, the 4awg you bought, is it CCA or OFC?
There's a big difference in load capacity between the copper clad aluminum and the oxygen free copper.

[evy]

Originally Posted by winmag4582001

Question, the 4awg you bought, is it CCA or OFC?
There's a big difference in load capacity between the copper clad aluminum and the oxygen free copper.

I was assuming it was copper...
Look at the pictures, it doesn't say anything about CCA or OFC.
it's very flexible, small strands.

I didn't pay much for it 40$/100feet, If it's aluminum and it's not big enough I'll just resell it on craigslist, is there a way to tell if it's CCA?

[winmag4582001]

The cut end will be silver in color if it's CCA. Solid copper color if it's OFC.

[evy]

Originally Posted by winmag4582001

The cut end will be silver in color if it's CCA. Solid copper color if it's OFC.

I see silver and copper...