The highest amperage kit I've seen has been only 150 amp. I'll fry something using that.
What are you using that draws 150+ amps continuously?
I'm looking an active switching isolator to keep my "house" battery (for accessories) charged while driving and to keep my "start" battery isolated while using accessories.
You can use any VSR (voltage sensitive relay) to switch a larger solenoid if so desired. To clarify your use, how many and what size in A/Hr capacity are your house batteries, and what do you use them for?
One thing to understand, whilst you alternator may be capable of producing 230 amps, most likely the only time it ever would, would be when winching.
A lead acid battery's ability to accept a charge is controlled by the chemical reaction and internal resistance of the battery.
For a ~100 A/Hr battery...........
So lets say you "dead" flatten your house battery to 10.5 volts. You start your car, the main battery charges up to the preset voltage of approx 13.2 volts for 5 or 10 seconds before your battery isolator switches your house battery into circuit. At that point it starts accepting a charge at a high rate, but that rate falls very quickly, and generally, in 10 seconds would probably fall below 100 amps, due to the internal resistance of the battery.
Even having a 500 amp alternator will not fully charge that battery in one hour, because of the chemical make up of the battery, "basically" it may accept 50~100 amps for the first 1/2 hour and 25~50 amps for the next 1/2 hour and 10~25 amps for the next 1/2 hour and 5~10 amps for the next 1/2 hour, and 2~5 amps for the next 1/2 hour and then finally a trickle for the next few hours until fully charged.(dependent on battery).
So your battery isolator will not see 150 amps for any "significant time period" to be concerned about.
Winching - If this isolator has a manual mode which is used when winching.
EDIT: I need to clarify this a bit, as what I wrote without a wiring diagram was a "general" description.
When winching from both batteries, manual mode selected, and your winch drawing it's maximum current, say 450 amps, that's 225 amps from each battery. The alternator is running, you have the engine revving, and the alternator is outputting "up to" 230 amps. So 110 amps minimum from each battery leg ( 110 thru the isolator to the winch). If you only use your house battery for winching, then a max of 230 through the isolator. Remembering, the alternator also still has to supply the engine and all other accessories as well so probably more like 175A maximum through the isolator for a short time.
As soon as you stop winching, the house battery can now receive a charge from the alternator. In the real world I doubt the alt will output 230A and more will be drawn from each battery, until the batteries get down a bit. If you connect your winch to your house battery (DON'T), then your isolator will try to handle the current of your main battery plus the alternator, ~300 amps, and whilst it can probably handle it for a few runs, it will ultimately fail at some point down the track. So hook your winch to which ever battery has the permanent alternator feed to it(normally your main battery)
Your alternator specification will also be at a certain speed, a certain temperature and would rarely ever output that actual specification in general use. If you think you will be doing regular "serious" winching, I would recommend using one of these, and when you get out to hook up the winch, turn this sucker on and go for it, turn off when you put the winch away.
HD-Series Heavy Duty Selector Battery Switch - Blue Sea Systems or other high current electrically operated solenoid.
Solenoids, their ratings, you need to find what they are, continuous duty, intermittent duty etc. A standard 100A continuous duty solenoid type isolator may have an intermittent rating of 400A for 10 seconds. (By the way, the solenoids in a standard Warn winch{up to a few years ago at least, I haven't check late model ones} are 100A solenoids)
So the products below, or many other like them, are generally very adequate for the job you describe, unless there are particular specs/usage scenarios you haven't told us about.
https://www.redarc.com.au/Content/I...arc brochure - SBI Smart Battery Isolator.pdf
Electronic Battery Isolator | Intervolt
Single Rectifier Battery Isolators
There are many automatic battery isolators, some are solenoid, some are MOSFET, some are programmable, some have multiple relays in parallel in them to achieve their current ratings. I won't go into all the good and bad about each, however, from my experience doing repairs, "I personally" would stay away from the ones with multiple relays in them as the load can be unevenly shared across the relays due to different contact resistance then they can burn out. I have used a Redarc SbI12 for 15 years, I don't do a lot of winching, if I did, I would fit the Blueseas switch as well. YMMV
Or has anyone created their own kit purchasing a high amp isolator, wire, etc. and doing their own install?
