Adding an onboard charger

[Broke Pilot]

Hey guys, now that I'm all moved into the new house I can get back to messing with the boat.
I'm looking at putting an onboard charger on it. I've got 2 batteries with the factory VSR and switch ('06 24SSV GG)
I've searched and read everything I can find but I can't figure out if it's ok to run a 2 bank charger and charge both batts at the same time with the VSR. I know I can charge through one battery and that's what the VSR is for, but I don't like the thought of relying on that when the charge/float/maintenance voltages are so low. Seems like it might be switching a lot. Also, on a side note, anyone know if the factory one is a dual or single sense?

I know this is the wrong forum, but the Supra forum doesn't seem to be the happening place to be anymore. Hopefully one of you guys running a VSR will have the answer.
Thanks y'all!

[dusty2221]

You can run a dual bank and run each bank directly to its own battery. Charge with the switch in the off position (at least I would).

Make sure your charger is rated somewhere within 10% in outout amps as your total battery amp hour capacity.

[MLA]

Broke

In the most ideal setup, the dual bank charger will be wired directly to the batteries and the VSR will not be closed during shore charging. However, this can be effected by the brand of VSR, style of switch used and how they are all wired.

[Broke Pilot]

It's a BEP VSR, they came factory on the supra with the dual batts.
So if I turn the batt switch to off, does that completely cut the VSR outta the loop?

[zd215]

I have a ProSport 12, dual bank charger with the factory BEP VSR and switch.
I ended up wiring a relay inline on the VSR sense wire where it is only able to sense battery voltage when the switch is on.
The logic is, if my battery switch isn't in the off position, I'm more than likely far away from shore power. The VSR will never bridge the batteries if it cannot sense voltage on the starting battery, this maintains positive battery separation when the switch is in the OFF position.

Notes from my relay wiring schematic.
30 - Starting Battery Sense (-) ground to relay
86 - 12v Switched Engine Wire (+) Energizes coil on 12v when switch is on 1, 2, 1+2
85 - Battery Sense Jumper from 30 (-) Provides ground for relay coil
87 - Relay Sense (-) To VSR sense input

[gregski]

It's a BEP VSR, they came factory on the supra with the dual batts.
So if I turn the batt switch to off, does that completely cut the VSR outta the loop?
Like MLA said it depends on how it's wired... maybe someone on here will know the specifics of how the factory did it but you might need to dig in a little to figure it out. Here are a few ideas:

The BEP VSR doesn't have an enable/disable switch. So whenever the sense voltage is above 13.7, it closes the relay. I would expect most chargers to output something around 14.5V so this would close the relay unless you have some other isolation switch and it sounds like you might.

Where is your battery switch (electrically not physically) with respect to the BEP? Take a look at the BEP VSR manual and compare to your setup. http://www.jgtech.com/pdf/VSR_instructions.pdf Notice that they have two examples, the left one shows the VSR on the "isolated" side of the engine switch (the load side, not the battery side); while the right drawing shows the VSR on the non-isolated/battery side of the switch. Figuring this out will be key to answering your questions.

Is it critical to charge each battery independently / Do you need to care if the VSR connects both batteries and charges them in parallel? Notice the recommended layout in the BEP VSR manual on the right. They show one charger connected to the house battery, using the VSR to connect to the starting battery (once the voltage is above 13.7V). This seems like a reasonable setup to me. You could get a bit of relay chatter if the charger has only enough power to hold 13.7V for the house battery but not both together. If you used a single output charger sized to handle both batteries, I don't think this would be an issue. You said that you don't want to rely on that method because the charge/float/maintenance voltages are so low. I don't think that "so low" is a fair description. Take a look at the pro sport manual: http://promariner.com/wp-content/uploads/2013/05/ProSport-Gen-3-Manual.pdf page 7. The charge voltage is 14.6V which is plenty to close the relay and charge both batteries. The maintenance voltage is 13.4 so this will open the relay and only keep a maintenance voltage on one battery but the reconditioning charge would go to 14.6V again and apply to both batteries.

[MLA]

Yes, the type of battery switch and how the switch and VSR are wired, make a difference. Two things to consider when using a single bank charger to charge 2 banks through a VSR 1) This may be ok is both batteries are same size, type, age and and used the same as in alternating between 1 and 2 from one outing to the next. If the batteries are different and used different, as in one is a dedicated cranking battery and the other is a dedicated house battery, then they will need to be conditioned and charged differently from each other. Passing through a VSR wont allow for this. 2nd, The VSR starts out open most likely, so the charger begins its bulk charge on the main cranking, which is likely not low at all. As the voltage rises, the VSR closes and brings in parallel a house battery which is certain to be low. Now the charger is finally charging the low battery, but through the cranking battery and through the VSR. After awhile then batteries are going to get close to their full charge, so the charger is going to taper off to its float mode. At some point, the VSR could open back up, isolating the house bank before it was fully charged. This is a generic scenario depending on the specs of a VSR/ACR.

So the most ideal route, is to go with a dual bank charger connected to each each bank and take the VSR out of the equation.

[sandm]

iirc, it was mla that convinced me to spend the few extra $$ for the prosport dual bank and it was good advice.
I have one side connected to the start battery and the other to the deep cycle(I have another deep cycle wired pos-pos and neg-neg to that one and approx 12ft away). never had an issue yet.

[Broke Pilot]

Yes, the type of battery switch and how the switch and VSR are wired, make a difference. Two things to consider when using a single bank charger to charge 2 banks through a VSR 1) This may be ok is both batteries are same size, type, age and and used the same as in alternating between 1 and 2 from one outing to the next. If the batteries are different and used different, as in one is a dedicated cranking battery and the other is a dedicated house battery, then they will need to be conditioned and charged differently from each other. Passing through a VSR wont allow for this. 2nd, The VSR starts out open most likely, so the charger begins its bulk charge on the main cranking, which is likely not low at all. As the voltage rises, the VSR closes and brings in parallel a house battery which is certain to be low. Now the charger is finally charging the low battery, but through the cranking battery and through the VSR. After awhile then batteries are going to get close to their full charge, so the charger is going to taper off to its float mode. At some point, the VSR could open back up, isolating the house bank before it was fully charged. This is a generic scenario depending on the specs of a VSR/ACR.

So the most ideal route, is to go with a dual bank charger connected to each each bank and take the VSR out of the equation.

This is exactly why I didn't want to charge through the VSR. You sir hit the nail on the head.
On top of that, now this is spiraling out of of control. One of my batts tested bad, I new it was dying, so... It's time for a complete electrical rebuild anyway. I will be running 2 different size batts and I'm going to go in and rewire all the stereo grounds to the battery to try and get rid of some noise through the speakers.

[MLA]

and rewire all the stereo grounds to the battery to try and get rid of some noise through the speakers.
Good chance that unwanted noise is not ground related.

[Broke Pilot]

Why do you say that? I have a very light hum when the engine is running, it gets a touch louder if the blower is on. And the wake plate causes a click in the speakers. I think the head unit is he only thing that needs to have the ground moved. If I remember correctly it's grounded to the bus bar under the dash. When I bought the boat it had 3 noise isolators behind the head unit. When one of them failed, I removed them and now I have the noise.

[MLA]

Those GLIs typically mask a noise, not fix. If the head unit is grounded on the helm BUS, its likely drawing its B+ under there also.

[David Analog]

GLIs are nasty band-aids. They have a few legit applications, like for instance, when mixing AC and DC audio components or isolating grounds between phone chargers and audio inputs. But in most cases they are masking an installation problem that should be corrected.
GLIs use tiny transformers to break the flow of DC between audio components. Inexpensive GLIs induce their own phasing and filtering problems that can hurt the sound quality. People rarely spend the extra bucks to get a really good quality GLI. Fix the core issue and give the GLIs the boot.

[Broke Pilot]

I guess I wasn't incredibly clear on 'rewire all the stereo grounds to the battery'... All the amp grounds are wired to the batts, obviously. The only part that's not is the headunit. It's wired to the ground bus under the helm. And the GLi's have been gone for a while, I know they're band aids, but they were working til one failed and I pulled them.
I put my new batteries in though yesterday and ran across something interesting, the positive and ground for the accessories on the helm are wired to the accessory battery. The cables even have labels zip tied to them that say -accessory and +accessory. So in essence the headunit is grounded to the accessory battery.
So... Now I'm wondering if that's where my noise is coming from now that the GLi's are gone. All the accessories, bilge, blower etc are on the accessory battery, which doesn't seem right to me. Those should be on the crank batt right? But like I said, this is a factory install from supra. They wired it that way. But hat doesn't explain where my alternator noise is coming from when he motor is running.

[David Analog]

It is still going to be very important to run new and dedicated B+ and ground wires of a good gauge from the supply source to the HU or any other source electronics. Here's why. Even though they may currently be routed to the same ultimate destination, you don't know what is going on between point A and B. How many times does that wire change buried in the harness? How many connectors and what type? What gauge wire? What other supplies are carried on that same long run? Exactly how long is that run? That factory harness run can offer substantial resistance. And resistance translates into a voltage change. That's all you need to induce a ground or supply loop.
Now, afterwards you may discover that you have another issue to contend with. But there is little to no chance you will diagnose a second issue as long as the problem is mask by the first issue.

[Broke Pilot]

Very true, thank you... So here is the plan, I'm going to move the accessory battery cables to rhe cranking battery, so that all of the accessories are running off of that one (the way I'm pretty sure it should be). I'll run a dedicated pos and neg to the accessory battery from the HU.
Here's where it gets tricky... Once all the accessory switches are on the crank battery my switch 12v for the headunit will be too. Should I also runs power and ground from that switch to the stereo battery and separate it also? Or is the switch 12v enough to cause noise?

[David Analog]

Many boats do not require this extra step. Many others do corresponding with a substantial audio system upgrade. Many buy cheaply designed amplifiers that do not have the ability to reject this type of noise at the input...or require that they go to excessive lengths to re-route RCA cables (two different issues that better quality amplifiers can impact). My opinion is that when you are executing the upgrade, go ahead and run the extra wiring at that time while it is a painless exercise. Then you are covered in any case.
The next issue often becomes maintaining the original key or switch functionality, while obtaining isolation from the factory harness. One easy solution is to add a basic relay that is triggered by the factory key or switch but interrupts/passes-through the supply from the direct source. These two parts of the relay are totally isolated.

[zd215]

Be careful moving your accessory leads over to the cranking battery. Now items such as your blower, pumps, and lights will be putting drain on your cranking battery. A recipe for getting stranded if you float for a while.

I rewired my VSR setup and entire audio system over the winter and left the accessory leads hooked up to the 'stereo' battery since it wont leave me stranded if i drain it completely. My head unit switch on the helm operates off the accessory lead, that switch operates a relay on my amp board that the head unit is connected to. The actual power feed to the head unit comes from the same distribution block my amps are wired to, which is directly to the 'stereo' battery.

[Broke Pilot]

I like it... Thanks guys. I think I have my plan.

[David Analog]

Be careful moving your accessory leads over to the cranking battery. Now items such as your blower, pumps, and lights will be putting drain on your cranking battery. A recipe for getting stranded if you float for a while.

I rewired my VSR setup and entire audio system over the winter and left the accessory leads hooked up to the 'stereo' battery since it wont leave me stranded if i drain it completely. My head unit switch on the helm operates off the accessory lead, that switch operates a relay on my amp board that the head unit is connected to. The actual power feed to the head unit comes from the same distribution block my amps are wired to, which is directly to the 'stereo' battery.

^^^ Great advice. Not everyone thinks things out to their conclusion like this. And with every different scheme, like a conventional dual battery switch, or VSR, or VSR with dual circuit switch, the wiring may change.

[Broke Pilot]

I like the relay idea... That's the route I'm going. I don't want to move be the cables over, it'd be easy but Probly not beneficial in the long run

[MLA]

One other thing to consider when placing the helm supply on the house battery, is where is the ignition key switch getting its B+ from? We would hope its coming from the engine, specifically off the main starter cable, which in turn, is connected to the main cranking. Also need to consider the use of the blower, if you routinely run your house bank very deep while out. May have a slow blower while getting ready to restart boat. Also the auto bilge, if you wet slip the boat. Cranking banks are rarely ever down when a boat is put away.

[Broke Pilot]

I come from a go fast boat boat family, so I always have the engine hatch popped open for start if the boat has been sitting for more than 30 minutes. I've seen way to many bilge fires as a kid out on lake Mead in Vegas. Any less and I'll run the blower. The boat is never wet slipped, so not too worried about the bilge pump.
As far as the ignition itself, I'm not sure where its power is coming from. But I know an easy way to find out. If I ever make it home from this trip from hell I'll start messing with it again.

[zd215]

On my boat, it appears the ignition and Batt+ for the ECU is tapped off the starter where the 2/0 gauge wire connects. That 2/0 wire is the one hooked to the output of the battery switch.

I'm thinking the factory intended to have the accessories on the second battery, and the starting battery only connected to position 1 on the switch. There are many ways to wire a boat, do what meets your requirements.

It doesn't matter what I leave switched on in the boat or for how long, I'll never have to worry about parasitic drain on the starting battery. Turn the switch to position 1, pretty much a guaranteed start every time!