Battery Question

[Andy]

That commenter is mistaking your two house power breakers (or possibly one house and one windlass? Unclear from the video) for a combiner. Those are the two small black devices to the right (aft) of your battery switch. A diode combiner looks similar at first glance, but that’s not what you have. It’s also far from “new” technology- in fact, where installed they should generally be replaced with a voltage sensitive combining relay (VSR) as the diode combiners tend to rob you of about a volt of charging potential. There is no “combiner” visible to my eye anywhere in your system.

The black and yellow box to the left (fwd) of your switch is another breaker. I suspect it’s for the aux. charging lead from your outboard. This is a separate charging feed from your alternator, giving you the ability to charge another battery back other than the one connected to your engine’s starter cable. I suspect that this is involved with your simultaneous charging ability; however I’d still like to see how it’s wired. Most commonly you see it simply wired to one of the batteries, especially if one is a bigger “house” bank. But if that were the case, in either position 1 or position 2, both alternator charging leads would be connected to the same battery- still leaving one without charging current. That’s clearly not the case.

Thank you once again!.. Do you know what the small black device is? The one that's mounted directly below the Guest switch?

 

[pelagic2530]

Thank you once again!.. Do you know what the small black device is? The one that's mounted directly below the Guest switch?

That is an inline fuse holder, almost certainly for the 24h power feed to your bilge pump float switch. If you look at the decal on it it should tell you its purpose and the amperage of the fuse inside. Very important that the fuse amperage match the fuse size listed on the pump.

 

[Blueghost93]

Do we have a link to this BEP cluster I would buy if I’m going to rewire my boat? I have a starting battery and a house battery.

 

[pelagic2530]

Do we have a link to this BEP cluster I would buy if I’m going to rewire my boat? I have a starting battery and a house battery.

You'll want the BEP 716 140A DVSR cluster, in either the square or horizontal configuration as best fits your application. Manufacturer page is here: Square Battery Distribution Cluster for Single Engine with Two Battery Banks

A quick google search will yield numerous shopping options, and a search for “BEP” on here will yield a ton of specific information.

 

[djtheo]

Think about it this way.

Whatever position you have the switch in, is what is powering not only your engine cranking, but also your house electrical load. However, it’s also the only thing getting charged by the alternator when the engine is running. So if only one battery is selected, the other one is isolated and remains in the charge state it started in. If “both” is selected, then both batteries are being charged, but both will also be drawn down if using power with the engine off, potentially leaving you without a sufficient charge to start the motor.

That said, there’s no major consensus on the right way to run that type of setup. The BEST option would likely be to start the motor on one battery, then switch to BOTH for the ride out to ensure both batteries are fully charged. Then, if you’re going to turn the motor off and drift while using electrical power, switch back to one battery while the engine is off. That way, no matter how discharged the online battery gets, the other battery is fully charged for engine cranking. Then, repeat the process when making the longer run in at the end of the day. For short start up and moves, I’d recommend keeping it on one battery- that way, that one battery is getting all of the charging current during the shorter engine run time.

As you can imagine, that can end up being a lot of battery switching back and forth, and if you forget a step somewhere you run the risk of two dead batteries and no way to crank the motor.

A far better solution is to simply separate your batteries into house and start circuits, using a BEP switch or another type of dual-circuit switch with a DVSR to charge both batteries. With that system, it’s just two switches on at the beginning of the day, two switches off at the end. No chance of a discharged cranking battery. That modification has been discussed at length here; a quick search should yield all the information you could want.

As an aside: do you know which of your batteries are designated 1 and 2? It doesn’t always line up with the switch dial positions. Probably worth taking the switch off the bulkhead and checking out which lead is on which terminal.

I was talking to my Yamaha Tech and they mentioned it was not a good idea to run on both as the engine is then having to account for different electrical inputs and could cause more harm than good...he said the preference would be to only run them one at a time.

 

[tomc585]

I was talking to my Yamaha Tech and they mentioned it was not a good idea to run on both as the engine is then having to account for different electrical inputs and could cause more harm than good...he said the preference would be to only run them one at a time.

Get a new tech.

 

[pelagic2530]

Get a new tech.

Yeah… that’s definitely not how that works.

Was this guy working at a dealership?

 

[Ozdogg]

I think I'm going to take Andy's advice. I appreciate all of the feedback from everybody on this thread.

 

[pelagic2530]

I think I'm going to take Andy's advice. I appreciate all of the feedback from everybody on this thread.

I recommend testing your system in the way that Andy tested his to ensure that your batteries are also receiving simultaneous charging current regardless of switch position. There is nothing inherent to a new boat that will cause that to happen unless rigged in a specific manner to facilitate that. If yours is so rigged, go forth and be happy. But it's worth it to develop a thorough understanding of your system so that you know, beyond a shadow of a doubt, that you have sufficient reserve capacity to support engine starting at all times.

 

[Andy]

I think I'm going to take Andy's advice. I appreciate all of the feedback from everybody on this thread.

Yes, I recommend doing as Pelagic recommends. Check yours with a multi-meter; it's a very easy test.

 

[Ozdogg]

I recommend testing your system in the way that Andy tested his to ensure that your batteries are also receiving simultaneous charging current regardless of switch position. There is nothing inherent to a new boat that will cause that to happen unless rigged in a specific manner to facilitate that. If yours is so rigged, go forth and be happy. But it's worth it to develop a thorough understanding of your system so that you know, beyond a shadow of a doubt, that you have sufficient reserve capacity to support engine starting at all times.

Thanks Pelagic.

 

[Mpellet]

I steer clear of battery arguments but I will confess how I have always managed the batteries in my current boat, a Parker 2520 equipped with 2 batteries and a single engine and previously, a Grady White outfitted with a single engine & 2 batteries , dating back to the 1980s. Both boats equipped with the standard Bat 1 /Both/ Bat 2/ OFF rotating battery switch. I start & run on BOTH batteries and when I shut down at sea , I switch to battery #2 to run the electronics. I don’t ever touch the battery switch with the engine running. YES, I’m aware that as long as you don’t go to OFF, you can safely move the battery switch with the engine running but I’m thinking there has been more then one brain fart that has resulted in that switch being rotated to the OFF position with a running engine. As a fan of the KISS principle, hands off the battery switch with a running engine helps to close that brain fart window.

Prior to start, I go back to BOTH batteries.

Occasionally, I will test each battery‘s individual ability to start the engine independently but if I do this with all my electronics running, I may get a reboot of some of the electronics that are more sensitive to voltage drops.

I run Interstate Batteries and swap them out every 7-9 years. The batteries have all still been functioning when I’ve replaced them but have not pushed my luck past 9 seasons with a set of batteries.

The above is an explanation of how I manage MY batteries. I’m not interested in an argument or getting a lesson from anyone on how to run my batteries. What I do works for ME but I’m not encouraging anyone to follow my lead or claiming it to be the best or only way to do business, it’s just MY way.

I will add that I can read alternator output on my engine gauges, so if my engine were to quit charging while underway , the voltage drop on the batteries would immediately be noticed.

I have never needed it (KNOCK ON WOOD) but if you were to dig through the duffel bag that I use to haul my offshore clothing to and from my boat, you will find one of these just in case.


Remarkable piece of equipment that weighs less and takes up less space than a six pack of bottled beverages. I’ve used it to successfully to jump an assortment of vehicles including a 26 year truck equipped with a 454 ci engine with a stone dead battery and a cold soaked engine with temperatures in the teens….

 

[warthog5]

but if I do this with all my electronics running, I may get a reboot of some of the electronics that are more sensitive to voltage drops.

What I refer to as "Spiking" the electronics.

 

[jimbobsomd2]

I steer clear of battery arguments but I will confess how I have always managed the batteries in my current boat, a Parker 2520 equipped with 2 batteries and a single engine and previously, a Grady White outfitted with a single engine & 2 batteries , dating back to the 1980s. Both boats equipped with the standard Bat 1 /Both/ Bat 2/ OFF rotating battery switch. I start & run on BOTH batteries and when I shut down at sea , I switch to battery #2 to run the electronics. I don’t ever touch the battery switch with the engine running. YES, I’m aware that as long as you don’t go to OFF, you can safely move the battery switch with the engine running but I’m thinking there has been more then one brain fart that has resulted in that switch being rotated to the OFF position with a running engine. As a fan of the KISS principle, hands off the battery switch with a running engine helps to close that brain fart window.

Prior to start, I go back to BOTH batteries.

Occasionally, I will test each battery‘s individual ability to start the engine independently but if I do this with all my electronics running, I may get a reboot of some of the electronics that are more sensitive to voltage drops.

I run Interstate Batteries and swap them out every 7-9 years. The batteries have all still been functioning when I’ve replaced them but have not pushed my luck past 9 seasons with a set of batteries.

The above is an explanation of how I manage MY batteries. I’m not interested in an argument or getting a lesson from anyone on how to run my batteries. What I do works for ME but I’m not encouraging anyone to follow my lead or claiming it to be the best or only way to do business, it’s just MY way.

I will add that I can read alternator output on my engine gauges, so if my engine were to quit charging while underway , the voltage drop on the batteries would immediately be noticed.

I have never needed it (KNOCK ON WOOD) but if you were to dig through the duffel bag that I use to haul my offshore clothing to and from my boat, you will find one of these just in case. View attachment 36111


Remarkable piece of equipment that weighs less and takes up less space than a six pack of bottled beverages. I’ve used it to successfully to jump an assortment of vehicles including a 26 year truck equipped with a 454 ci engine with a stone dead battery and a cold soaked engine with temperatures in the teens….

 

[pelagic2530]

What I refer to as "Spiking" the electronics.

And which sensitive modern electronics particularly enjoy.

 

[jimbobsomd2]

Mpellet, you explanation about a traditional 2 bank battery switch echos in my mind everytime I see a switch discussion. While my routine is only slightly different, it is basically the same. I am Just now replacing my two batteries installed in 2015 on my 2520. Prior to that the Deka batteries were the originals to my 2005 vintage.
My prior boat had the same setup. I owned that boat for 24 years. Never had an issue using the same routine. At that time I was on a 7 year replacement schedule.
In essence, I second your advise of KISS. And no I am not advising anyone or interested in a conversation to convince me otherwise. This simply works for me and obviously a lot of others. It is not rocket science.
Thanks for listening.

 

[pelagic2530]

Mpellet, you explanation about a traditional 2 bank battery switch echos in my mind everytime I see a switch discussion. While my routine is only slightly different, it is basically the same. I am Just now replacing my two batteries installed in 2015 on my 2520. Prior to that the Deka batteries were the originals to my 2005 vintage.
My prior boat had the same setup. I owned that boat for 24 years. Never had an issue using the same routine. At that time I was on a 7 year replacement schedule.
In essence, I second your advise of KISS. And no I am not advising anyone or interested in a conversation to convince me otherwise. This simply works for me and obviously a lot of others. It is not rocket science.
Thanks for listening.

Since neither you or Mpellet are interested in being convinced otherwise, this comment is directed to any other viewers that may be reading this thread. You guys can feel free to skip, because I’m going to get long winded here.

I’ve said it before, but I’ll say it again. Battery management via a properly installed 1-2-both-off switch or switches does work. It can be done and it has been done, for many years, by many people.

What it CANNOT do is the following:
-Provide isolation between house and starting circuits. Whatever position the switch is in is the source of power for the output post, to which both the engine and house power cables are connected. By definition, therefore, both circuits are common and will see any influence in the other. This means that the house power system, including highly voltage-sensitive electronics, will see voltage spikes during motor cranking, when high amperage going to the starter will sharply pull down the system voltage, which then spikes back up as the alternator kicks in and begins providing 14+VDC to the same system. Electronics do not like this, and may power down, generate system errors, and in some cases sustain damage. Every modern piece of electronic equipment is now a computer; computers like stable voltage. Likewise, with the engine off, the house circuit will draw down whatever source it is connected to, with no protection at all to ensure that a fully charged battery remains available for cranking service.
-Provide simultaneous battery charging for isolated batteries. Again, with a traditional switch the only battery that is seeing charge current is the one that is lined up with the switch dial. If in the Both position, then yes, both batteries are being charged. But in any other position, only one battery is actively being charged. The other one will remain in whatever charge condition it started in.
-Allow for the use of different battery sizes and types for maximum system effectiveness. Since both cranking and house loads are being supported by whatever battery is selected, you’re getting very little benefit out of selecting and installing the right battery for the task at hand. Modern battery construction allows for a high degree of specialization in battery type: cranking circuits can use small, power-intense, cranking batteries, which provide high CCA ratings at the expense of some AHs (which are mostly irrelevant to cranking service anyway). They’re also usually lighter and significantly cheaper than a deep cycle. Quality deep cycle batteries, on the other hand, offer impressive power densities and construction that allows significant depth of discharge without damage to the battery. Pairing a dedicated cranking battery with a high-quality, properly sized deep cycle battery gives you the absolute best of both worlds and the highest degree of system performance.

Nor do I accept the “KISS” aspect of the argument for the traditional switch. All a BEP switch is, is three ON-OFF switches and a VSR (which is not critical to basic system function). From a design standpoint, I think it’s a tough argument to make that three single position switches are inherently more complicated than a four-position switch with multiple internal contacts. I’ve seen 1-2-B-O switches fail internally; I can’t recall the last time I saw a simple On-Off battery switch fail. From an operational standpoint, I argue that your system is MORE complicated: in order to responsibly manage your boat’s electrical system, I have to set my switch to one battery, crank my engine (remembering to start up my electronics AFTER doing so, to avoid voltage spikes), then switch to BOTH for the ride out to charge both batteries, then switch to one battery when I get out there to keep a charged battery in reserve, repeat that process as I move around during the day, switch back to BOTH for the ride in, etc. etc. You’re talking interacting with your battery switch multiple times during the day, if you’re doing it responsibly. And if you’re NOT doing it responsibly, you’re running the risk of a discharged cranking battery. Since you’re intentionally putting your batteries in parallel, it’s incumbent on you to isolate them again, which adds a high degree of potential for human error.

Contrast that to my BEP switch: I turn the HOUSE and START switches on at the beginning of the day. I run around, starting and stopping my engine as I choose, and then at the end of the day I turn those same switches off. That’s IT. Two interactions. My VSR takes care of all the rest. And if the VSR fails, guess what? I’m in the same position you guys are, but I still maintain my system isolation. I just turn my yellow emergency parallel switch on when I want to simultaneously charge both batteries, and off when I want them isolated. There is no physical way that my batteries can become inadvertently paralleled, unless I close the yellow switch, which is not something I have to do on any regular basis. In theory, the system should function it’s entire life without ever being placed into “emergency parallel” mode.

To summarize, there is really no argument as to why the 1-2-B-O switch is a better system than a BEP switch, because it’s not. It’s less effective, it’s not appreciably “simpler”, it requires more user action. The only thing it IS, is familiar. If you want to make the “it’s what I’ve always done and I like it that way” argument, or the “I make it work and I don’t feel like spending a few hundred dollars on an upgrade” argument, or the “I don’t feel like learning how a new, improved piece of equipment works” argument, then that’s fine, you do you. But insinuating that both systems are equally effective ways of conducting battery management is patently incorrect.

Thanks for coming to my TED talk. I’m happy to discuss further with anyone who has questions.

 

[jimbobsomd2]

My response was not meant to be thought provoking or argumentative in nature.
However since everyone’s scenario is different, a broad based assumption about our setup and boat mooring(trailer, in marina slip or at home at your own pier on a lift) has not been entered into your equation and reasoning. Yes I see some benefit to your suggestion about the BEP. The cost is not an issue with me. I am in the middle of repowering my boat in my dealers shop right now. I am still going with a positive experience with all of the boat’s ( familiarity) dual battery switches. Never a failure. I doubt the BEP would either. They are simply stupid switches with no brain like a light switch in your house.
I want to remind you that modern electronics compensate for the very issues you address but you did not mention that. How does one explain the manufacturers statements about acceptable operating voltage ranges and temperature parameters? There are more factors in this discussion that we really don’t need to bring up. Computers have come a long way, voltage spikes are not nearly as dangerous to electronics as they once were because the electronics recognize the “spikes “ at the on-site of voltage rise(or fall) instantaneously and compensates.

For the record, my boat IS kept at home, on a lift, since purchased new. I do not travel more than 30 miles from home port nor are overnight trips, bait wells, radar, and other high amperage accessories in my repertoire and I have a two bank onboard modern charger that I utilize on a weekly basis just to accomplish the equalization of charging that you stress.

So I just wanted to let you know that there those of us that do not fit into the need to change for the sake of change. I am all for staying up to date with all things electronic, but at this time in battery switch management there is only a small benefit to my situation.

Again, I am not being rude, just letting you know about the other side of regular boar owners that don’t have to switch up the things that has been proven in their own situations. By the way, I always use one battery for the whole day of fishing and cruising. Charging that battery all day whenever engine is running. The second battery is my reserve at full charge since it was never used. The next day number two is used….. then I plug in the onboard charger to maintain full charge in each all over again.
Never a dead or low battery…. Just saying…
I know this was long but it needed to be said. Thanks I really like Classic Parker by the way.

 

[pelagic2530]

I appreciate your detailed response. It sounds like you’re doing a good job of conscientiously managing your battery power needs with the setup that you have. Given your particular situation, I agree that you would likely see only minimal benefit from upgrading your switch.

That said, if the time comes where a replacement becomes necessary, I would highly suggest an upgrade at that time.

I’ll continue to disagree with you regarding voltage spiking of electronics. While they can operate across a range of voltages, it’s the rapid fluctuation in voltage that they don’t like. They can compensate for various input voltages, but they want it to be steady. It might not kill them, but it’s not good for them either. The problem is exacerbated when you have weak batteries, bad connections, or corrosion somewhere in the system that magnifies the voltage drop during cranking. Unfortunately, you’ll be unlikely to notice these situations developing before the damage is already done.

Of note is the fact that most higher-end boatbuilders have stopped using this type of switch. Generally speaking, they’ve switched to using either dual circuit switches with a parallel position with VSRs, or BEP style battery management. Parker remains an exception to this rule, along with some traditionally “price point” builders.

One more note regarding the 1-2-B-O switches. If you have them, pull them off the bulkhead and inspect the terminals from time to time. All of the ones I’ve seen have had bare brass terminals on the back that are a magnet for corrosion. For what it’s worth, the BEP switches are all tinned components on the back.

 

[Mpellet]

While we’re on the subject of potential failure points, m

One more note regarding the 1-2-B-O switches. If you have them, pull them off the bulkhead and inspect the terminals from time to time. All of the ones I’ve seen have had bare brass terminals on the back that are a magnet for corrosion. For what it’s worth, the BEP switches are all tinned components on the back.

So far I have had decent luck with battery switches (KNOCK ON WOOD), but over the years I have had 2 of these breakers fail.