Stereo Isolation Switch?

[pdxbirchy]

What is the best way to be able to run the dash radio and speakers without killing the engine battery? We installed such awesome speakers in the coach it seems like a shame not to use them when parked. Or am I better off just going with a big Bluetooth speaker and not chancing it ever?

 

[Matt Colie]

Marcelo,
As your coach is a 23, it might have the house bank in the right front. It is a Coachmen, so I am not sure, but if you have the isolator and the combiner in the same place as a GMC, then just add a pair of inline fuses and them for both the keep alive and the main power. You can switch the main power if you care so it will go off with the ignition, but I never cared, so ours is on the house bank all the time. Please note though that we store Chaumière at home and always on shore power so it doesn't matter if the radio is on. This is good because it usually is.
Matt

 

[LQQKatJon]

What is the best way to be able to run the dash radio and speakers without killing the engine battery? We installed such awesome speakers in the coach it seems like a shame not to use them when parked. Or am I better off just going with a big Bluetooth speaker and not chancing it ever?

Simply run a circuit up to the radio off the “house” side.

 

[pdxbirchy]

I have aspirations of moving the house bank to the rear bath closet and upgrading that bank to lithium. I think that is where it will land, at least. So I guess I would need to figure out what else up front is running off of house battery!

 

[LQQKatJon]

I have aspirations of moving the house bank to the rear bath closet and upgrading that bank to lithium. I think that is where it will land, at least. So I guess I would need to figure out what else up front is running off of house battery!

I am not entirely familiar with birchhavens. But I believe there is both house side and engine battery wiring up front in the hatch. Moving batteries should not change much.

On my 75 palm beach I created a sub fuse panel off the boost solenoid up front and fed the stereo off that. I think I have a couple other added circuits off the house side up front.

 

[kidjedi]

My PO got sick of a dead starting battery from "the kids running the radio," and he told me he just permanently connected the house and starting batteries together. Only once have I had a starting issue, and for some reason using the "battery boost" switch on the dash made it fire right up (which makes me think the radio is still running off only the starting battery). I *REALLY* need to figure out how the PO has modified everything, so I don't get stranded somewhere boondocking (or mess up the house 12v system if it's somehow running off the alternator all the time ). I also need to buy one of those little battery packs that can charge devices but will also start a Ford F350. Those things are amazing!

 

[Matt Colie]

Kid,
I think I would like to nominate your PO for having the worst ideas for a GMC that I have ever heard of and very possibly the worst modifications ever reported.
Matt

 

[Christo]

Kid,
I think I would like to nominate your PO for having the worst ideas for a GMC that I have ever heard of and very possibly the worst modifications ever reported.
Matt

If the boost switch worked, maybe the PO didn't simply connect the batteries together, but instead installed a Yandina combiner across the outer terminals of the isolator. That's a popular upgrade.

 

[Blur911]

Hmm, would a voltage sensing relay connected to the radio and both battery banks work? If the engine is running and charging it switches to that, if not it's on the house bank. Leave the keep alive connected, it doesn't take much current.
Or, an adjustable voltage monitoring relay set to shut off the radio power if the battery voltage falls below a certain level so as not to kill the battery. voltage monitoring relay
Or am I overthinking it? The solution lies in modifying what you have now, which rarely seems to be stock on these machines.

Roxie's radio is almost always on, connected to the house bank on shore power, but switchable to coach bank.

 

[RF_Burns]

If the PO has connected the house and engine batteries in parallel, you need to disconnect that connection and isolate them. Use either a Diode Isolator as GM did in OEM configuration, or use a Combiner. If you are using lead acid batteries for both, then a Combiner is a good idea as it will charge both battery systems from either engine alternator or shore power converter.
Another good idea is to install a battery monitor between the house battery and its loads. The battery monitor will disconnect the house battery loads when the battery voltage drops below a preset level. This saves your battery from damage should you leave the radio ON or any other connected load for an extended period.

I use this:

60 Amp 12V/24V Battery Guard | BG-60 | Samlex America

Prevent excessive discharge of 12V/24V batteries & protect electronics against overvoltage using a Samlex BG-60 programmable 60A Battery Guard.

samlexamerica.com

 

[kidjedi]

Kid,
I think I would like to nominate your PO for having the worst ideas for a GMC that I have ever heard of and very possibly the worst modifications ever reported.
Matt

Well... I will say, he did a LOT of things right too. I just share a lot. Also, like I said, I may be completely off base about what he did with the electrical. I just haven't had the opportunity to really get in there and trace everything. Everything seems to work when I need it, so I've just been knocking on wood.

And he also did me the "solid" of telling me about everything, and I still text him every once in a while and he almost always answers pretty much immediately. I actually really appreciate my PO.

 

[kidjedi]

If you are using lead acid batteries for both, then a Combiner is a good idea as it will charge both battery systems from either engine alternator or shore power converter.
Another good idea is to install a battery monitor between the house battery and its loads. The battery monitor will disconnect the house battery loads when the battery voltage drops below a preset level. This saves your battery from damage should you leave the radio ON or any other connected load for an extended period.

I use this:

60 Amp 12V/24V Battery Guard | BG-60 | Samlex America

Prevent excessive discharge of 12V/24V batteries & protect electronics against overvoltage using a Samlex BG-60 programmable 60A Battery Guard.

samlexamerica.com

Yeah... the reason I keep making excuses and not really digging in is that I keep telling myself I'll be upgrading to Lithium soon, and that will be a WHOLE LOT of research and learning. Right now everything is Lead Acid, so relatively easy as far as the technology goes. I haven't really looked into it deeply, but I'm sort of surprised that the separate starting battery hasn't gone the way of the Dodo. Costco carries deep cycle AGM starting batteries now (largely because there are so many gadgets and gizmos in a vehicle that have a much higher draw than what batteries used to need to supply). With AGM house batteries and an AGM starting battery, it seems like someone would have found a good way to just combine it all. Perhaps the reason it hasn't happened is simply for the safety of redundancy (two separate sources to make sure the vehicle will start).

 

[Matt Colie]

Kid,
An AGM battery has little advantage as a starting battery unless it is a rolled cell AGM. (Looks like a 6 pack) The values of them are: They have very low internal resistance (the rolled cell only), they can be recharged faster, and they are service proof - but they should not need any either. Other than that, they are just lead/acid batteries with a higher price tag.

I do(did) a lot of boat work, and believe me, if the racers (distance types) could do with one less battery, they would. They all are very tuned to watching what batteries that they do have. If they need either the VHF or the little diesel to be there when they need it, things could get really bad fast.

Cruising boats and performance cruisers (read retired racing sloops), are a different breed and very much like RVers. They aren't tuned at all to paying constant attention to the batteries. So, any quote I write will be based on the experience that they will at some point have the house bank dead and need power. So, the engine start is an isolated system. Only if requested will I even include an interlock like our boost switch and that my be something that requires a tool to engage.

So, even with a real battery monitor (not just a voltmeter), it is still worth your while to maintain the divided systems. While they may have some common charging like the isolator so both banks charge from the main engine, or a combiner to change both from shore power, the separate systems can pull your cubes out a bad situation because you can still fire the main engine after lights have gone dark.

I do not know if you have read, but there is a chance lithium will go short because of the surging demand and the Chinese control of the production, so keep you options open as long as you can.

Chaumière is early enough that she carries a separate generator battery and that was my recovery one very memorable occasion. I don't have room in the back for a house bank and don't want to buy the copper to crank the Onan from the front jars.

Matt