Wiring and Battery Addition

[jcb1977]

Dude what is your deal, do you have an issue?

No issue. I disagree with your assessment that voltage spikes are most probably caused by incorrect wiring. many causes of voltage spikes but not worth debating.

 

[HangOutdoors]

No issue. I disagree with your assessment that voltage spikes are most probably caused by incorrect wiring. many causes of voltage spikes but not worth debating.

The fact that it could of spiked right after the wiring was modified would be reasonable to deduce that, that was the cause. Of course spikes can happen for other reasons.

 

[jcb1977]

The fact that it could of spiked right after the wiring was modified would be reasonable to deduce that, that was the cause. Of course spikes can happen for other reasons.

I fried two connext screens....the first time was after wiring modifications (battery add and switch replacement) but with no apparent errors that I could find. Brought it into the dealer for a warranty claim, they checked wiring and they could not find any cause and replaced it under warranty. Yamaha replaced with no questions asked.

Replacement screen was installed with no modifications to the wiring from above. Worked for a year + with no issues and then fried again randomly. Dealer/Yamaha replaced under warranty with no questions asked. At this point, I replaced the single circuit 1/2/both/off and re-wired with a dual circuit on/off switch. No issues with that screen for a year + until I upgraded to a 2024 250 this winter.

Dealer said this was a common issue even in boats with stock wiring. The connext screen is/was sensitive to voltage spikes and can't ride through a relatively minor voltage spike while the rest of the electronics on the boat can absorb without issue. There are too many incidents of this issue on the forum to be a coincidence. Yamaha knows there's an issue and its why haven't challenged the warranty replacements.

I believe the spikes were caused when charging and the selector is switched through the off position on a 1/2/both/off switch. It's why I switched to a dual circuit on/off.

 

[HangOutdoors]

So taking the charging circuit out of the system via the on off appears to be optimal. Wondering why the fuse to the connext wouldn't blow during the spike?

 

[jcb1977]

So taking the charging circuit out of the system via the on off appears to be optimal. Wondering why the fuse to the connext wouldn't blow during the spike?

As I understand it, the fuses only protect against overcurrent and provide little protection against voltage spikes. I spent a lot of time trying to find voltage protection devices but never came across anything that was practical for DC systems.

Normally, I would always turn the battery switch to off when charging the batteries. but once in a while, I would forget and leave the battery switch in the 1 or 2 position while hooked up to the chargers. In this scenario (or while boat is running), switching from the 1 to 2 position through the off position may cause a sudden spike by quickly disconnecting and reconnecting charger. below is an article I found suggesting this. For me, I think it happened not with the boat running but with chargers connected. Just a theory but the best I could come up with. That and I believe the connext screens can't handle even a slight spike like most other electronics can handle. No other electronics including my garmin chartplotter had any damage during either event of mine.

The dual circuit, on/off switch doesn't' allow for that scenario with only two positions on the switch. I actually preferred the single circuit 1/2/both/off setup but not worth the potential damage keeping that switch if the theory is true.

The Perko 1/2/both/off switch is laid out better to switch through the both position. The Blue seas version is not and makes it very easy to switch through the off position. Either way, I'll be sticking with Dual Circuit On/off switches going forward.

"Blown Alternator Diodes & Voltage Transients:
This big blunder happens when you, or a crew mate, tries to switch to another bank and pass the battery switch through the *OFF position, even momentarily. With the engine running and the alternator charging this creates an open-circuit between the alternator and the load (load = battery bank) it’s charging. Momentarily passing through OFF, or disconnecting the load from the alternator, can cause a massive voltage spike as the load/ battery bank is disconnected from an alternator. This quite often results in damaging the alternators rectifier diodes & rendering it non-operational near instantly. it can also damage sensitive electronics that are connected to the “C” post of the switch.

*Most quality 1/2/B battery switches, from reputable manufacturers like Blue Sea Systems, BEP/Marinco, Guest & Perko, are designed to be make-before-break. Make-before-break means that as you turn the switch from position 1, to BOTH or 2, the previous position does not open-circuit or disconnect until the next position can carry the current."

 

[Clacava]

I wanted to post what I ended up doing using your install as a guide but did a few things differently.....before this I had installed a second battery with a single circuit layout (1/2/off/combine switch). I fried two connext displays for some reason, still not exactly sure why, but before I get the third screen installed I figured I should try changing something to try and avoid it. Figured I would try a dual circuit with on/off switch this time. I mounted the negative busbar on a piece of wood blocking using the bolts for the table holder (I do have a cover for the ground busbar but didn't have it on when I took the picture).

View attachment 186037View attachment 186038View attachment 186039View attachment 186041

how does this isolate the house battery when engine is off to run the radio etc? the switch seems to only have on, off and combine. What makes it run off house only when engine is off

 

[jcb1977]

how does this isolate the house battery when engine is off to run the radio etc? the switch seems to only have on, off and combine. What makes it run off house only when engine is off

Both batteries are active whenever the switch is in the on position.....all the accessories (radio, connext, lighting, etc) are wired to the House Battery. The only thing wired to the Start batteries are the engines. So when engines are off, there should be no draw off your start battery.

 

[Clacava]

This worked without killing your connect screen?

With the SI-mcr you wired it outside the batteries, the M-acr recommends it be wired between the batteries, does that made a difference?

 

[jcb1977]

With the SI-mcr you wired it outside the batteries, the M-acr recommends it be wired between the batteries, does that made a difference?

Not sure exactly what you mean but you want the ACR on the load side of the switch if you want to isolate independently charge each battery. If you only have a single source for charging like solar, you would want the ACR on the battery side of the switch so it combines both batteries into one for charging.

 

[Clacava]

With the SI-mcr you wired it outside the batteries, the M-acr recommends it be wired between the batteries, does that made a difference?

The diagram on the M-acr box shows to wire the acr directly to the positive battery terminals of both house and start battery. The pictures in this thread from HanGoutdoors, his diagram and picsU using a SI-acr, which is different) show that the acr is wired to the load side of switch. I want to be able to have both batteries charging while running boat, then use only house for radio etc when anchored.

 

[HangOutdoors]

The diagram on the M-acr box shows to wire the acr directly to the positive battery terminals of both house and start battery. The pictures in this thread from HanGoutdoors, his diagram and picsU using a SI-acr, which is different) show that the acr is wired to the load side of switch. I want to be able to have both batteries charging while running boat, then use only house for radio etc when anchored.

Not really sure what you are asking.

When my switch is off my batteries are off. They charge independently on my on board shore Charger, since I have each wired to a bank on it and my batteries are isolated and charge independently then. I have wired my engines to my starting battery as well as one of my bilge pumps (I have two). On my house battery I have it ran to a fuse block right there and to one under the helm. They both charge when the engine is on via the ACR when the Switch is in the On position. They are independent for load unless I combine them.

 

[Clacava]

Not really sure what you are asking.

When my switch is off my batteries are off. They charge independently on my on board shore Charger, since I have each wired to a bank on it and my batteries are isolated and charge independently then. I have wired my engines to my starting battery as well as one of my bilge pumps (I have two). On my house battery I have it ran to a fuse block right there and to one under the helm. They both charge when the engine is on via the ACR when the Switch is in the On position. They are independent for load unless I combine them.

Sorry let me try to clarify, I wired mine the way it shows on the diagram from Bluesea. Which shows the acr, wired directly to the batteries. I am asking will the acr work the same if it is wired to the battery switch, load side, as above.

 

[jcb1977]

View attachment 218027Sorry let me try to clarify, I wired mine the way it shows on the diagram from Bluesea. Which shows the acr, wired directly to the batteries. I am asking will the acr work the same if it is wired to the battery switch, load side, as above.

If wired on the battery side of switch it will combine batteries for charging when boat engines are in and proving a charge. At rest, it will isolate them as you want. But when using shore power to charge them it will also combine when a charge is present.

If you wire it on the load side, everything above is the same except when you charge on shore power, the batteries will not combine and you will be able to charge each battery separately on its own smart charger which is better for longevity.

 

[Clacava]

View attachment 218027Sorry let me try to clarify, I wired mine the way it shows on the diagram from Bluesea. Which shows the acr, wired directly to the batteries. I am asking will the acr work the same if it is wired to the battery switch, load side, as above.
[/QUOTE

If wired on the battery side of switch it will combine batteries for charging when boat engines are in and proving a charge. At rest, it will isolate them as you want. But when using shore power to charge them it will also combine when a charge is present.

If you wire it on the load side, everything above is the same except when you charge on shore power, the batteries will not combine and you will be able to charge each battery separately on its own smart charger which is better for longevity.

Ok got it, as I thought, however, can the load side and the battery side on the switch be swapped. My switch is a little different, the terminals are diagonal from each other not on top of each other. with my switch I am unable to get the fuse block on the left of the switch as in the pic above. My pic, Top terminal is #1 going to the right is #1, #2 then #2. so my loads are the two with the wires on them.

 

[jcb1977]

Shouldn’t matter m-acr vs si-acr

 

[Clacava]

Shouldn’t matter m-acr vs si-acr

Can the load and battery terminals on the switch be swapped

 

[jcb1977]

Can the load and battery terminals on the switch be swapped

I believe so.

Can the load and battery terminals on the switch be swapped

I would think the terminals are reversible as long as you keep 1 load/1 battery and 2 load/2 battery aligned.

 

[Clacava]

I believe so.


I would think the terminals are reversible as long as you keep 1 load/1 battery and 2 load/2 battery aligned.

Thanks, solved that problem, last one, with the acr being ran to the batteries as the directions say, do I need to put the batteries in parallel, meaning do I need to connect the negative of house to neg of start.

 

[jcb1977]

Thanks, solved that problem, last one, with the acr being ran to the batteries as the directions say, do I need to put the batteries in parallel, meaning do I need to connect the negative of house to neg of start.

You would want to create a common ground by connecting House and Start Battery negatives along with all other equipment grounds. The positives of course would be wired to separately to the battery switch.

 

[Clacava]

You would want to create a common ground by connecting House and Start Battery negatives along with all other equipment grounds. The positives of course would be wired to separately to the battery switch.

Thank you I have a buss bar to connect all negs, together.