Roadtrek 2008 210 Isolator replacement

[wny-pat]

Thinking of swapping out my isolator for a seporator. Am considering replacing it with a Sure Power 1315-200 Bi-Directional Battery Separator. Has anyone done this and if it is doable what problems might I run into? Does it matter if it is Uni-Directional vs Bi-Directional?

[Rlum]

Originally Posted by wny-pat

Thinking of swapping out my isolator for a seporator. Am considering replacing it with a Sure Power 1315-200 Bi-Directional Battery Separator. Has anyone done this and if it is doable what problems might I run into? Does it matter if it is Uni-Directional vs Bi-Directional?

2016 PW Lexor TS here. About a year ago. I changed out mine. Actually was pretty straight forward. Just turned off the switch to house battery bank. Disconnected the chassis battery negative pole. Check the separator power connections with multimeter. No voltage. Changed out and replaced with new separator. Used bidirectional. Why? It was the OEM. I guess a unidirectional would work as well. There is a small ground wire on back. When chassis battery is up to 13.4 or higher, the switch is closed. If separator is malfunctioning, the switch stays closed and does not open. When this occurs, separator stays closed and is always warm. House and chassis battery are constantly connected so higher voltage drains to lower batteries. An easy test is just disconnect the ground. This will open the separator circuit and keep batteries separate.

[Stevemo]

Contactors do not limit current so you may have your breakers tripping at high RPM if you have a big alternator and a low coach battery.

I like the dual sensing contactors because they charge both ways. Start your engine and it charges your house battery automatically. Plug in to shore power and it charges your starting battery automatically.

[Road Toad]

Originally Posted by Stevemo

Contactors do not limit current so you may have your breakers tripping at high RPM if you have a big alternator and a low coach battery.

I like the dual sensing contactors because they charge both ways. Start your engine and it charges your house battery automatically. Plug in to shore power and it charges your starting battery automatically.

Which dual sensing contactor do you recommend?

[Nic7320]

If you ever want to upgrade to lithium batteries, you may want to use a DC to DC converter that has a lithium charge profile instead of an isolator. Isolators and charge relays (sometimes called 'smart relays') are best used with similar battery chemistries (Pb-acid, Gel, AGM are all lead based). Lithium has different charging requirements and a much lower internal resistance.

There are lithium batteries that claim to be drop compatible but it's still better not to mix them with other battery types.

Another thing a DC-DC converter can do is limit the load on your alternator. But that's a topic for another thread.

[Stevemo]

Blue Sea has a few options, I did a video on one of them:

https://www.youtube.com/watch?v=kNBBcMGaZQY

My system is going to be overbuilt and expensive but it won't accommodate lithium batteries. I will probably install a 2nd alternator in the future so I'm going big.

I agree with Nic on his statements about the DC converters. The last option would be the old diode isolators.