Battery Help

[Rocketman]

It seems you're trying to complicate the simple. I'm not sure why you are stuck on that distribution panel. It's a converter power center that takes 110-volt AC power and converts it to 12-volt DC current, and it's a battery charger. Adding a second battery charger like the CTEK, while it adds a transfer switch, it's a little redundant.

Of course...if i knew what I wanted/needed, I wouldn't have to ask . I'll reconsider the distribution panel if need be, but for now I just want to get the rest of the system addressed to a point that I'm comfortable with. I think you have it with the link provided below.

But OK, it seems you want a 100% 12-volt system in the van, never needing the use of an inverter for 110-volt appliances, and only using 110-volt appliances when they are plugged into shore power or running off a generator. Correct?

You are 100% correct. The only thing I've ever used an inverter for is the laptop and since I've got the smartphone, the laptop is used maybe 10% of the time compared to before. I can run the generator if I need the laptop. Actually seems simpler to me?

If so, get this: Rapid Mobile 3 Way Automatic Transfer Switch

I've only glanced at it so far, but that is probably exactly what I'm looking for.

Incidentally, you mentioned "if I disable whatever amount of charge the generator is sending back through the starter cable..." Define "starter cable" please. Do you have your generator connected to the van's starter?

Obviously not a good description on my part. In that case I am referring to the starting cable of the generator. The cable that runs from the auxillary battery to the generator's starter and also carries some amount of 12v charge back to that same auxillary battery. I will likely have that charge disabled though, just to eliminate any chance of it being a problem. If the generator is running and I have a charger, there is no need for it anyway.

 

[Turtle]

On the "starter cable", OK, now I know what you mean. You won't need to disable that. You can leave it alone, just the way it is. The charging current that comes back though it is uber minimal, literally a trickle charge to replace the amps needed to start the generator in the first place. It'll send an amp or so, two max to the aux battery, and even then if there is another charging source connected to the battery, the voltage present in the battery from the other charging source will push back the trickle charge. The trickle charge will be around 13.0-13.2 volts, which isn't a "charging" voltage, it's more of a "maintaining" voltage. Remember voltage is like water pressure, the higher the voltage the higher the pressure.

The idea of using the generator for any 110 volt loads seems simple, but it's not quite as efficient as running the laptop off an inverter. With the generator running, it's generating a whole lot more electricity than you'll be using. Better to use the generator to run larger loads, like a battery charger to recharge the batteries, or an air conditioner, and then run the low amp loads like the laptop and such right off the aux battery. But it can certainly be done either way.

The benefit of that 3-way transfer switch is that you can add an inverter to it without any problems. And it can be a small one, like a 600W or 800W inverter.

To the transfer switch, you make a shore power connection, and connect the generator, and then plug any 110 volt loads right into the switch. Whatever source you are using, generator or shore, you'll have power. You'll plug a battery charger into the switch, so that whenever you have shore or generator power the aux battery will be charged.

You can get a battery isolator that works both ways, meaning if there is a charging source to the aux battery, the cranking battery will be connected and will be charged at the same time. As soon as the charging current disappears from either end (alternator or generator/shore), the cranking and aux battery are disconnected and isolated from each other.

It should be a rare thing when you have the van running and charging the aux battery, and the generator or shore power also connected and charging the aux battery at the same time. If you do that a lot or for extended periods, then you'll want to install something like this between the isolator and the aux battery to shut off the circuit from the alternator.

 

[Rocketman]

Ok, I'm starting to get the idea. It's bedtime for now though. I've got plenty of time to plan it out.

Thanks for the info!

 

[Rocketman]

The idea of using the generator for any 110 volt loads seems simple, but it's not quite as efficient as running the laptop off an inverter. With the generator running, it's generating a whole lot more electricity than you'll be using. Better to use the generator to run larger loads, like a battery charger to recharge the batteries, or an air conditioner, and then run the low amp loads like the laptop and such right off the aux battery. But it can certainly be done either way.

I can play with what I have now a bit and see if I want to do it that way.

The benefit of that 3-way transfer switch is that you can add an inverter to it without any problems. And it can be a small one, like a 600W or 800W inverter.

To the transfer switch, you make a shore power connection, and connect the generator, and then plug any 110 volt loads right into the switch. Whatever source you are using, generator or shore, you'll have power. You'll plug a battery charger into the switch, so that whenever you have shore or generator power the aux battery will be charged.

Yep, I understand the transfer switch. Actually had that explained to me by an RV guy a while back. He and I just didn't get into the multiple charge sources to the auxillary battery. Using that switch though, I would have to add a charger. Which might be best anyway. I could probably buy a better charger than what comes in that distribution panel/converter/charger setup anyway. It looks like that transfer switch is set up for plugs though. I have my stuff hard wired now and would like to keep it that way. I'll look into it, I'm sure there are options for that as well.

You can get a battery isolator that works both ways, meaning if there is a charging source to the aux battery, the cranking battery will be connected and will be charged at the same time. As soon as the charging current disappears from either end (alternator or generator/shore), the cranking and aux battery are disconnected and isolated from each other.

I really, really like that I can charge both batteries from either source. I had been planning to use a switch similar to the Blue Sea Disconnect you linked to and have it so that I could jump the isolator and boost the start battery off the auxillary if need be (I just hadn't thrown that one at ya yet ). With this isolator, I'm not sure there's a need for it though. I even read something on one of Hellroaring's isolators that led me to believe that it had a built in jump feature?

It should be a rare thing when you have the van running and charging the aux battery, and the generator or shore power also connected and charging the aux battery at the same time. If you do that a lot or for extended periods, then you'll want to install something like this between the isolator and the aux battery to shut off the circuit from the alternator.

I'll know soon enough whether this is an issue that I need to address. I agree, probably not a regular occurence. And...as of right now, the alternator isn't hooked to it anyway, so no danger.

Most of my original post was worst case scenario..and for a reason. I wanted to get a good grasp on what I'm dealing with. I'll put some thought into the transfer switch and the inverter. At least I've got a pretty good idea that I'm not going to blow anything up. I've just got a Walmart deep cycle battery for now, but I may get a AGM later on to use as an Auxillary. I can always use this one on a trolling motor.