Using the boost switch as battery isolator

Forum for both AC and DC electrical components. From engine alternator to dashboard, inverter to batteries, and everything electrical in-between.
TDJohn
Posts: 552
Joined: Sun Oct 27, 2019 11:34 pm

Re: Using the boost switch as battery isolator

Post by TDJohn »

Robert K wrote: Sun Sep 13, 2020 10:26 am As I was getting parts to put the relay in I thought why not just change momentary boost switch to a latching on off switch,
Still thinking. ;)
Using a good quality latching relay, like the BlueSea brand, has some advantages, but in my humble opinion, it is not worth the cost and the hassle of installation. Be aware, if you want to install a latching relay, you will have to run a new wire form the front of the coach all the way to the back where the relay will be located. The way the current boost solenoid wiring is set up will not work for a latching relay.
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
TDJohn
Posts: 552
Joined: Sun Oct 27, 2019 11:34 pm

Re: Using the boost switch as battery isolator

Post by TDJohn »

Robert K wrote: Sun Sep 13, 2020 2:17 pm So I took the momentary switch out and hooked up a toggle switch to try it. Ithe worked fine for switching and I could see the voltage change when I started the engine.
I have the coach hooked up to 30 amp outlet so I let it charge.
I left it on for an hour or so, the solenoid was warm but I think that is probably normal.
I need to find a rocker switch to replace the boost switch on the switch panel .
If you can, please post a picture of the boost solenoid. Like I said before, if the solenoid is an OEM unit, it is VERY likely that the solenoid is actually rated constant duty, and you stating that the solenoid is only warm after extended use, further supports the high likely hood that you solenoid is rated for constant duty. So, I don't see any issues of you using what you have (save yourself time and money).

As for the switch, if you don't need to use both dash fans, maybe borrow one of the fan switches till you are able to locate on, this is what I did, since I use only one dash fan. Mel is good at finding places that sell needed parts, so maybe he can help you find a switch...
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
stuplich@ymail.com
Posts: 1146
Joined: Mon Oct 28, 2019 8:51 am

Re: Using the boost switch as battery isolator

Post by stuplich@ymail.com »

Bob K
1.) I believe the stock/original battery boost solenoid is not a "latching solenoid", not rated for "continuous duty" ... and
therefore not suitable for use as a battery isolator.

2.) A "Non-latching solenoid", (while combining both battery banks for charging), would be constantly drawing 12VDC power.

3.) Your existing boost switch can be used to activate a Continuous Duty Latching Solenoid:
https://www.discountstarterandalternato ... -cart-12v/
Last edited by stuplich@ymail.com on Tue Sep 15, 2020 9:51 am, edited 1 time in total.
Mel
'96 Sahara 3530, mine since '01
250 hp 3126 Cat, MD3060 Allison
TDJohn
Posts: 552
Joined: Sun Oct 27, 2019 11:34 pm

Re: Using the boost switch as battery isolator

Post by TDJohn »

stuplich@ymail.com wrote: Mon Sep 14, 2020 1:04 pm Bob K
1.) I believe the stock/original battery boost solenoid is not a "latching solenoid", not rated for "continuous duty" ... and
therefore not suitable for use as a battery isolator.


2.) A "Non-latching solenoid", (while combining both battery banks for charging), would be constantly drawing 12VDC power.

3.) your existing boost switch can be used to activate a Continuous Duty Latching Solenoid:
https://www.discountstarterandalternato ... f-cart-12v
/
Mel,

The OEM boost solenoids were not the latching type, but they were rated for constant duty. Constant duty solenoids can and do come in either style.

Also, the way Safari has the boost solenoid and switch wired, you can not use a latching relay without running additional wire.

Here is a link to a video explaining the latching relay: https://www.youtube.com/watch?v=B1gfe1g5tKA&app=desktop
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
stuplich@ymail.com
Posts: 1146
Joined: Mon Oct 28, 2019 8:51 am

Re: Using the boost switch as battery isolator

Post by stuplich@ymail.com »

TDJohn wrote: Mon Sep 14, 2020 5:05 pm Here is a link to a video explaining the latching relay: https://www.youtube.com/watch?v=B1gfe1g5tKA&app=desktop
Another link: https://www.youtube.com/watch?v=UGxJs5XaSWY
Mel
'96 Sahara 3530, mine since '01
250 hp 3126 Cat, MD3060 Allison
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