2nd Battery Quote...tell me what you think...

[txav8r]

And that is an interesting point. The factory only invests in supply and ground cables that are just large enough to service the existing electronics. But when the charging system is taken to task with particularly large audio systems, there comes a threshold where upgrading the factory cables can actually make a difference.

At what point do you think that comes into play @David Analog ? That's a good conversation, and one you and I have danced around before. If the amps aren't using the factory cabling to the engine, then why would it matter? If you take the power for the amps direct from the battery(s), and then recharge the batteries without a VSR/ACR, your charging an isolated battery, and your source is powered through correct gauge wiring. So why would factory cabling matter? I can see a deeply depleted battery coming into the conversation here, which may be no different than someone that never charges the battery and depletes it over time. But my question and thought is this...the engine doesn't support the actual power to the stereo system, it only supplements if you use the above mentioned vsr/acr. And the amps are powered directly from the battery, the engine charging system, an onboard or external charger, does so through a lamp cord basically. So I am not sure in our boats, why changing the engine cables would be necessary, but you have my attention! And gentlemen, this guy knows his stuff and I listen to his knowledge.

 

[David Analog]

I forgot why.

 

[txav8r]

Ha ha, I doubt that!

 

[jlcj7]

Very bad drawing i know... but please check my logic to make sure i am not missing anything... This is how i plan on wiring (unless i missed something)

• All battery cables will be 4 awg
• ground wire from ACR to negative bus is 16awg (with 10amp inline fuse)
• Engine and Accessory wires all exisiting
• Amp power and ground are new 10 awg (25amp inline fuse on power wire for 300W Clarion XC1410)

Based on previous posts i read, i do not plan on installing the start isolation wire (based on @txav8r previous post) nor the inline fuses from positive on battery to ACR (did i understand this correctly from previous posts?)

Open to feedback on this... i have all parts now except the battery cables (which i plan on making at West Marine per Julian's advice)...Thanks...

 

[Bill D]

Where are you going to locate your amp? You may want to upsize the cable if it is a decent size run.

 

[jlcj7]

I was planning on near the head unit.

 

[robert843]

@jlcj7 what switch are you planing to use?

 

[swatski]

Hey guys - if you install an on board charger, where do you hook it up in your schematic? Does it matter?

 

[Bill D]

I would upgrade your cables to the amp to at least 4 AWG to allow for the voltage drop in the wire.

Think about it like a water hose... If you know how much water (current) you want out of the end of a hose, there are 2 easy ways to get that amount of water; you can increase pressure (voltage), not really an option in this case because we have a 12V battery, or use a bigger hose to lower resistance. Bigger hose at the same pressure equals more water.

 

[jlcj7]

@jlcj7 what switch are you planing to use?

Blue Seas 7650

 

[robert843]

Thanks then yes that looks correct.

 

[txav8r]

Hey guys - if you install an on board charger, where do you hook it up in your schematic? Does it matter?

If you use any battery charger, you going to hook it directly to the battery posts. If you use a dual bank charger, it will have two sets of leads, and you hook to both batteries. If you run a single charger with a dual bank battery system, the charger can charge both banks, but doing so will confuse a smart charger and always see a good battery, even if you have one that is getting problematic. A dual charger is best. I am not big on on board chargers. I don't want the weight or the mass in the boat. So mine is mounted on the wall in the barn, and only the leads that attach to the batteries is in the boat and hangs out of the seatback on the swim platform. It is a dual bank PulseTech charger. It is a low amp charger, but the algorithm that Pulsetech uses actually charges at double the rate and desulfates as well as exercising the battery(s). 10-15 amps per bank is sufficient, because a lead acid battery can't absorb more than that per hour anyway, and it is more like 10amps unless it is an AGM battery.

 

[swatski]

If you use any battery charger, you going to hook it directly to the battery posts. If you use a dual bank charger, it will have two sets of leads, and you hook to both batteries. If you run a single charger with a dual bank battery system, the charger can charge both banks, but doing so will confuse a smart charger and always see a good battery, even if you have one that is getting problematic. A dual charger is best. I am not big on on board chargers. I don't want the weight or the mass in the boat. So mine is mounted on the wall in the barn, and only the leads that attach to the batteries is in the boat and hangs out of the seatback on the swim platform. It is a dual bank PulseTech charger. It is a low amp charger, but the algorithm that Pulsetech uses actually charges at double the rate and desulfates as well as exercising the battery(s). 10-15 amps per bank is sufficient, because a lead acid battery can't absorb more than that per hour anyway, and it is more like 10amps unless it is an AGM battery.

That is exactly the information I was searching for, THANK YOU @txav8r! I really appreciate.

And look what just arrived today - from another member, @ChargerGuy - refurbished, like new, great price. Mel - you are right, it is heavy!
I am adding a group 31 AGM deep cycle battery to the system, and trying to figure out how I want to go about it. This forum is fantastic!





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[tdonoughue]

If you use any battery charger, you going to hook it directly to the battery posts. If you use a dual bank charger, it will have two sets of leads, and you hook to both batteries. If you run a single charger with a dual bank battery system, the charger can charge both banks, but doing so will confuse a smart charger and always see a good battery, even if you have one that is getting problematic.

Mel, is this true even with the ACR? I thought that with the ACR when you had a dual-bank charger when you activate it, the ACR will close (thinking that the engines are running) and hook both batteries together? I have been planning to add a relay to switch the ACR to 'start' mode while on charger. But is that not necessary?

 

[txav8r]

@tdonoughue , I am not fully understanding your question. With a dual bank charger, both banks are charged and there is no need to let the ACR close and allow either charger to cross to the other battery. This is a reason that many will put the ACR between the two load posts on the switch, instead of between each positive battery post (this is the same as putting the ACR between the two battery lugs on the switch too). That way, the switch has to be on, in order for the ACR to close. If it is between the battery posts (or battery posts on switch), it will not only close when the engines are putting an appropriate charge to a battery, but it will also close if an external charger is putting a charge on either battery. This is appropriate for a single bank charger, but not for a dual bank charger. A dual bank charger will act independently to each battery bank with its individual charger. Disclaimer...as I mentioned, having a single bank charger charging two battery banks thru the ACR, can confuse a charger with "smart" technology. That means that if you depending on the charger to tell you if you have a dead cell or below/above amps, it won't, because it will most always see an appropriate number of cells even is one is dead on one battery, and low or high battery is balanced by the good one. It is a common misconception that your engine will charge the engine battery first too when an ACR is aboard. The ACR is merely a door. It is either opened or closed. When it allows current to pass to both batteries, battery condition will dictate which is topped first. The low battery is always the one that absorbs the most amount of charge, until they are equal, and then they will absorb more uniformly until full. All kinds of smart charger protections are lost when a single 12V charger is used simultaneously on a multiple battery bank system. Can it be done safely? I think so, but those protections are lost. That puts the responsibility of knowing your batteries condition and paying attention to any problems that develop. Also, when an ACR combines two separate banks, and they are in very different states of charge, the fully charged battery can actually provide more to the low battery than the charger itself, and the two batteries can literally balance out, meaning the low battery comes up and the full battery comes down. This can be a dangerous situation. Because that much higher current transfer for an extended period can create heat. We all know what happens when too much heat is generated. There are other devices that can be added for protection, to lock out a very low battery. And the ACR does have some circuitry to not allow it to close in very low situations. But some would say that is too low and that other devices should be incorporated. Here is a good thought however. Our stereo systems require a good many amps to operate. When they no longer will play or are distorting or having issues, it is probably due to low voltage. And that is when you should stop draining that battery and just turn the stereo off. Again, I haven't reached that point once but many will. If they are hitting that point, it may be a good time to add another battery to the stereo bank, or take the ACR out of the loop. There are some opinions here and not cold hard positions. And we have discussed these for years...and all my knowledge on this came from our discussions, weighted with my own opinion of them. I think you may be asking about the "starter isolation" that the ACR can do. I don't use it and our engines don't create enough electrical interference, nor do we have the sophisticated electronics that larger boats have...again, my opinion, but it has been validated by a number of minds brighter than mine. Hope this helps!

 

[tdonoughue]

@txav8r , ok. I think we are at nearly the same place.

With a dual bank charger, both banks are charged and there is no need to let the ACR close and allow either charger to cross to the other battery.

Yes, I agree there is no need to let the ACR close with a dual bank charger. However, with the ACR wired as shown in the diagram above, I believe that when you hook the dual bank charger up and energize it, the ACR *will* close. That would mean that if there was a potential difference between the two batteries, you still have the dreaded flow between the batteries, which then messes with the smart charger.

There is another input on the ACR for the 'starter' which prevents the ACR from closing (purportedly during starting). There was some thread here somewhere that suggested that the solution would be to install a relay in the charger line so that when it energizes, the relay trips and provides power to that starter input, thus preventing the ACR from closing.

This is a reason that many will put the ACR between the two load posts on the switch, instead of between each positive battery post (this is the same as putting the ACR between the two battery lugs on the switch too). That way, the switch has to be on, in order for the ACR to close.

Now *this* is interesting! I don't think that I have it wired that way. I think I have it wired the way that was shown on the Add-A-Battery Kit (which is what is in the diagram above). But if I do that, then there is no need for a relay. And life is much simpler.

Thanks for that! You just got me closer to a smart charger...

 

[Island Jay]

Thanks for the pic post of my charger!

Typically if you are charging two independent 12v batteries you want a 2 bank smart charger. Anything less may work, but you are only kidding yourself if you think it will be 100% safe and optimal.

 

[Julian]

When you are done, label the cables or twist tie them into groups with labels. I literally wrote on the red wires with a sharpie which battery they go to, and on the negatives I added labels. When I take them off, I use twist ties to keep them together per post. I did this after I missed one one spring and my stereo head unit wouldn't come on (I ran a remote wire to the battery to keep the presets alive). Turns out I'd put the remote wire on the wrong terminal and the effect was to prevent the stereo from coming on.

So I bought a whole new stereo and remotes and amp (cuz there was no point in going half assed at it), and hooked it up exactly the same way again....and the new one wouldn't come on! So I went back to square one and checked ALL my wiring and connections....then noticed the remote wire.... LOL Moved it and voila....(so didn't need the new HU in the first place....but don't tell my wife that! LOL)

 

[swatski]

Thanks for the pic post of my charger!

Typically if you are charging two independent 12v batteries you want a 2 bank smart charger. Anything less may work, but you are only kidding yourself if you think it will be 100% safe and optimal.

That is what I figured, corroborated in here by @txav8r.
I posted a pic of my onboard charger install in another thread on the topic https://jetboaters.net/threads/where-to-mount-battery-charger.8611/.

 

[txav8r]

View attachment 34124
Here is an adaptation of what Blue Sea recommended. It is exactly the same as their two cables between the batteries. But instead, you run the
View attachment 34125

When you are done, label the cables or twist tie them into groups with labels. I literally wrote on the red wires with a sharpie which battery they go to, and on the negatives I added labels. When I take them off, I use twist ties to keep them together per post. I did this after I missed one one spring and my stereo head unit wouldn't come on (I ran a remote wire to the battery to keep the presets alive). Turns out I'd put the remote wire on the wrong terminal and the effect was to prevent the stereo from coming on.

So I bought a whole new stereo and remotes and amp (cuz there was no point in going half assed at it), and hooked it up exactly the same way again....and the new one wouldn't come on! So I went back to square one and checked ALL my wiring and connections....then noticed the remote wire.... LOL Moved it and voila....(so didn't need the new HU in the first place....but don't tell my wife that! LOL)

im going to try that one @Julian! Surely I could get w good upgrade on something with that same tactic, sounds smart to me