Replacing diode isolator with smart separator

[SteveJ]

I'm looking at replacing the possibly failing old style four wire isolator with this from KeyLine.

https://www.keylinechargers.com/prod...-artic-cat-etc

I didn't find a current draw on their website so I sent the company an email. Does anyone happen to have the info?

I considered a Blue Sea but it only has a 120 amp rating vs 140 for KeyLine and the KeyLine has an IP65 rating.

Other brands that would work? The current isolator is mounted to the main van frame, exposed to the elements.

I'm assuming that the alternator cable should be attached to the starting battery terminal along with the battery cable and that the thin fourth wire would no longer be used.

I'm also considering a cutoff switch for the house battery(flooded lead acid) to avoid overcharging.

Comments?

Thanks in advance.

[booster]

Blue Sea also has a very nice 500 amp version.



https://www.amazon.com/Blue-Sea-Auto...s%2C208&sr=8-5


We have the manual version of the same unit as we don't have use for the automatic part.

[markopolo]

If the actual manufacturer of the product is Aopec then they list 3mA standby current for most models - AOPEC Automotive Electronics - Products

Some are dual sense which allows the starting battery to be charged when on shore power. Some are single sense so alternator charging only.

I installed an Aopec R12140B unit in my van 5 years ago. It's inside the van. It works as expected. Turned out to be dual sense so it's a nice addition to my van. The old isolator is actually still in place, completely separate wiring but in parallel to the Aopec.

I'd probably go with Blue Sea if needing something along these lines again if for no other reason than the terminals which look to be better able to be used with heavy gauge wiring.

[SteveJ]

Having had some coffee and thinking a bit more on it, I'm leaning toward this from BlueSea:

https://amazon.com/gp/product/B000OT...KIKX0DER&psc=1

It has an IP67 rating vs the IP65 on the KeyLine. I was original concerned about the 120 amp rating with a 140 amp alternator(I think). But following the current flow, it would be extremely rare(and likely catastrophic) to have anywhere near that current going to the house battery. I was originally think about how the diode isolator worked, with all of the alternator output going through it. I do like the latching relay, keeping operating losses to a minimum. And it's a bit more frugal.

Thanks to both of you for the replies.

[booster]

Originally Posted by SteveJ

Having had some coffee and thinking a bit more on it, I'm leaning toward this from BlueSea:

https://amazon.com/gp/product/B000OT...KIKX0DER&psc=1

It has an IP67 rating vs the IP65 on the KeyLine. I was original concerned about the 120 amp rating with a 140 amp alternator(I think). But following the current flow, it would be extremely rare(and likely catastrophic) to have anywhere near that current going to the house battery. I was originally think about how the diode isolator worked, with all of the alternator output going through it. I do like the latching relay, keeping operating losses to a minimum. And it's a bit more frugal.

Thanks to both of you for the replies.

We used to have a couple of them in one of our test setups of charging systems and they worked well. I think on those you can even use the ignition interrupt to switch on and off, but not sure, as that is nice to do when the batteries are full.


You will almost certainly not cook one with a stock 140amp alternator, which won't put that out for long, and would fry itself if it did. Blue Sea probably also give a surge spec someplace the would be even more cushion.

[SteveJ]

Originally Posted by booster

We used to have a couple of them in one of our test setups of charging systems and they worked well. I think on those you can even use the ignition interrupt to switch on and off, but not sure, as that is nice to do when the batteries are full.


You will almost certainly not cook one with a stock 140amp alternator, which won't put that out for long, and would fry itself if it did. Blue Sea probably also give a surge spec someplace the would be even more cushion.

Agreed with all of the above, though not certain if the ignition interrupt is meant for continuous duty. I'm likely not gonna worry about this unless I go with AGM batteries in place of my single LA battery, which I doubt as the single battery works well for us.

[Hatteras Jim]

I've been using the 200 amp isolator from Powerwerks (https://powerwerx.com/battery-separa...eries-200-amps) and have been happy with it. Not sure of its waterproof rating since mine is mounted inside and is not a concern. Only thing that I didn't like is when my on board charger was charging the vehicle battery, it would sense the higher voltage and automatically engage the house batteries. (Maybe they all do that?) Fixed that by installing a switch in the sensing circuit so I could control when my house batteries would charge. Usually have it on for traveling, off when camping. Solenoid does get warm.



IMO you do not want to go back to diode isolating systems.

[markopolo]

The amount of warmth or heat gives an indication of current consumption by the device.

That style isolator looks very much like the Surepower separator units discussed on RV forums. Current consumption is reported as being as high as 1.5A when latched. OK I guess when plugged in but not good if on solar for example.

[SteveJ]

Had fun installing the Blue Sea yesterday. Only one trip to the hardware store, win! It works a treat.