BEP Switch and House Battery Recommendations

[gregd123]

Hey gang. Wondering which BEP switch to use and looking for a recommendation on a house battery. Here is my setup:

2003 2520
Twin 2019 Suzuki DP200AP motors
Two existing relatively new Interstate 27M-XHD start batteries; plan on adding a third House battery

On the BEP, looks like my options are the 718-140A-DVSR or 717-140A-DVSR. It looks like the biggest difference is with the 717 you can run one engine (either) and once 13.7 volts is reached, the relay will open and charge the other start and house battery. With the 718, you have to pick one engine that has this feature. This issue goes away under normal operating when both engines are running. Did I understand this correctly? Are there other advantages/disadvantages to the two switch options? Is there a better switch for my setup?

For the House battery, I think my design load would be running the bait pump and anchor light for 8 hours with the engines off and maybe the radar and a radio for two hours. The bait pump is a Jabsco 50840 Series Marine High Flow, Low Pressure Cyclone Centrifugal Pump with 9 amp maximum current draw, radar is a GARMIN–Fantom 24 with ~2 amp current draw, and I eventually may add a stereo with an estimated 1.5 amp draw.

So that would be 72 amps for the bait tank, 4 amps for the radar, 3 amps for the stereo, plus couple amps for the anchor light, right? Thinking about using a Interstate Deep Cycle SRM-31 with 98 amp-hour rating. Thoughts? Will the BEP isolate the house battery at 50% capacity?

Last questions - 1) can I use either of the BEP switches with just the two start batteries now and add the house battery later? I am planning on moving the batteries from the stern to a new locker cut into the floor in the pilothouse this winter and 2) Are there limitations on what house battery is compatible with the BEP switches assuming I am using the Interstate wet start batteries (i.e. AGM, Li ion, Group D4 etc.)?

Thanks,

 

[warthog5]

Why install it now with No House battery? Just wait and do it all at one time.

You will need Power Posts mounted on the transom to extend the cables.

I ran a D4 DC House battery. It's = to 2 1/2 gp27's

You want the 717.....It's designed for Outboards.

The 718 is for Inboards.

https://www.bepmarine.com/en/Products/Battery-Management/Battery-Distribution-Clusters

 

[gregd123]

Thanks Warthog. Would the Interstate SM-4D be a good choice for the house battery?

 

[big_tuna]

That looks like a nice battery with 195 amp hours. you don't want to drain it past 50% so if it has 195 amp hours and you plan to use ~70, sounds like it will be a good option. You can buy a amp meter (https://www.amazon.com/gp/product/B07B4CWKRJ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1) to determine your amp draw. Multiply your amp draw by the number of hours you plan on staying on the hook, then you have the estimated amp hour usage for the battery.

I switched out my lights to LED that helps cut down power consumption with the nav lights.

I do have the BEP switch installed, I really like it....but I have only a single outboard. I have an interstate battery group 27 for my starting battery and a trojan group 30/31 for my house battery. Originally I had an interstate group 27 for my house battery and it sucked. Switching to the trojan was really nice.

I'm not dissing interstate, that D4 size battery will do much better than my group 27, I'm just saying trojan is considered top of the line so you may want to look into their options.

If I had the room, and it looks like you do, I would undoubtedly buy 2 trojan 6V batteries for my house setup. But I don't have that room on my 2310 unless I want to put a battery in v-berth which I dont' want to do....

 

[big_tuna]

here you can see the 2 batteries and the amp meter still hooked up to the interstate battery. I'd like to eventually install the amp meter display somewhere, but the cable on the hall sensor is not long enough

 

[warthog5]

Would the Interstate SM-4D be a good choice for the house battery?

It's the one I had This is the custom Stainless battery tray I built for it. I actually bought a box for it....I sent it back.....To big and bulky and battery moved around in it.

 

[pelagic2530]

Hey gang. Wondering which BEP switch to use and looking for a recommendation on a house battery. Here is my setup:

2003 2520
Twin 2019 Suzuki DP200AP motors
Two existing relatively new Interstate 27M-XHD start batteries; plan on adding a third House battery

On the BEP, looks like my options are the 718-140A-DVSR or 717-140A-DVSR. It looks like the biggest difference is with the 717 you can run one engine (either) and once 13.7 volts is reached, the relay will open and charge the other start and house battery. With the 718, you have to pick one engine that has this feature. This issue goes away under normal operating when both engines are running. Did I understand this correctly? Are there other advantages/disadvantages to the two switch options? Is there a better switch for my setup?

For the House battery, I think my design load would be running the bait pump and anchor light for 8 hours with the engines off and maybe the radar and a radio for two hours. The bait pump is a Jabsco 50840 Series Marine High Flow, Low Pressure Cyclone Centrifugal Pump with 9 amp maximum current draw, radar is a GARMIN–Fantom 24 with ~2 amp current draw, and I eventually may add a stereo with an estimated 1.5 amp draw.

So that would be 72 amps for the bait tank, 4 amps for the radar, 3 amps for the stereo, plus couple amps for the anchor light, right? Thinking about using a Interstate Deep Cycle SRM-31 with 98 amp-hour rating. Thoughts? Will the BEP isolate the house battery at 50% capacity?

Last questions - 1) can I use either of the BEP switches with just the two start batteries now and add the house battery later? I am planning on moving the batteries from the stern to a new locker cut into the floor in the pilothouse this winter and 2) Are there limitations on what house battery is compatible with the BEP switches assuming I am using the Interstate wet start batteries (i.e. AGM, Li ion, Group D4 etc.)?

Thanks,

You want the 717 model, as Warthog mentioned. There’s really no way to effectively make that system work without a house battery, so I’d do both installs at the same time.

Regarding your battery load: you’re going to need WAAAY more capacity than that. Cycling a battery deeper than about 50% of its rated capacity on a regular basis severely decreases its lifespan. So if you plan to use that amount of power regularly, for that duration, you need let’s say 90AH of useable power. That calls for a battery bank of about 180AH capacity; you’re probably in about Warthog’s 4D area.The BEP switch will isolate your start batteries so no worries there.

Compatibility will be fine as long as you’re using some variation of lead-acid batteries (traditional, AGM, gel, etc.). Lithium, I would contact BEP to get a final answer to make sure the VSRs will play nice with lithium voltages. Don’t see a reason they wouldn’t, but it’s worth checking. I would also shy away from regular gel batteries- they’re not designed to absorb the 14+ volts from outboard alternators and you risk damaging them by boiling the gel electrolyte. It’s difficult to beat the AGMs that are on the market these days- high charge voltage/amperage acceptance rates, deeper discharge ability, superior durability. I’ve had very good luck with Lifeline, but they’re pricey.

 

[gregd123]

Thanks again for everyone's response. Pelagic, I was under the impression that the amp-hour rating provided for the battery was a value that when expended, the battery would be at 50% capacity. Is this incorrect? A battery in good condition with a 100 amp-hour rating would be at ~50% capacity if say 10 amps were drawn for 10 hours right? Also, my understanding with deep cycle is they are designed to be drawn down to 50% without damage. Is this understanding wrong? At the end of the day, I will rarely be drawing the house battery down that much, maybe 4 to 5 times a year. Normally, I turn my engines off when fishing and the bait tank and whatever other electronics are on (MFD, radar, occasional washdown pump, etc) will run off the house battery for 15 minutes up to maybe 2 hours on a good bite .

 

[big_tuna]

Thanks again for everyone's response. Pelagic, I was under the impression that the amp-hour rating provided for the battery was a value that when expended, the battery would be at 50% capacity. Is this incorrect? A battery in good condition with a 100 amp-hour rating would be at ~50% capacity if say 10 amps were drawn for 10 hours right? Also, my understanding with deep cycle is they are designed to be drawn down to 50% without damage. Is this understanding wrong? At the end of the day, I will rarely be drawing the house battery down that much, maybe 4 to 5 times a year. Normally, I turn my engines off when fishing and the bait tank and whatever other electronics are on (MFD, radar, occasional washdown pump, etc) will run off the house battery for 15 minutes up to maybe 2 hours on a good bite .

If 10 amps wer drawn for 10 hours that is 100amp hours and you will have depleted a 100amp hour battery. But the battery you listed is.... what like 195 amp hours? So you would be right around 50%

 

[pelagic2530]

Thanks again for everyone's response. Pelagic, I was under the impression that the amp-hour rating provided for the battery was a value that when expended, the battery would be at 50% capacity. Is this incorrect? A battery in good condition with a 100 amp-hour rating would be at ~50% capacity if say 10 amps were drawn for 10 hours right? Also, my understanding with deep cycle is they are designed to be drawn down to 50% without damage. Is this understanding wrong? At the end of the day, I will rarely be drawing the house battery down that much, maybe 4 to 5 times a year. Normally, I turn my engines off when fishing and the bait tank and whatever other electronics are on (MFD, radar, occasional washdown pump, etc) will run off the house battery for 15 minutes up to maybe 2 hours on a good bite .

Here’s a pretty decent article on battery capacities: Amps, Amp Hours, and Battery Capacities for Boaters - boats.com

In short, no, the rated amperage of the battery is considered as “fully cycled”, i.e. fully charged to fully dead. As the article explains, the exact ratings are largely theoretical and are mostly used for comparison purposes; the actual discharge rate will affect the capacity pretty significantly.

I would be cautious about any battery that claims to be able to sustain regular discharge below about 40% charge state without damage, but I’m not a battery scientist. The basic science behind LA batteries (which despite changes in design, materials and configuration hasn’t changed much in a century) just doesn’t seem to support it.

If it’s going to be an “every once in awhile” thing, then you’re probably ok. I would make sure I had the BEP switch or some other way to ensure your start batteries are always charged, and I’d probably install a volt meter to keep track of my charge state. But as long as your cranking batteries are good, the major specter of a dead battery is somewhat minimized; you can always crank and run your engines to recharge.

 

[dstanl01]

If you have space 2 house batteries in parallel is an option too.

 

[gregd123]

Another thought on my project . . . is it a bad idea to put wet lead acid batteries in a compartment in the floor of the pilot house? They will be strapped down and I will vent (not sure how or how robust this needs to be?) the compartment. The pilot house takes significantly more pounding than the stern of the boat where the batteries are currently. Anyone who has moved their batteries forward have an issue with spillage or venting? I am aware the spillage issue goes away with AGM batteries.

 

[warthog5]

It should not be a problem......However.....I run into "Strapped" batteries all the time.

I want everyone that reads this.....If you have "Strape's " around your batteries.....Go see if you can slide them in the trays.....[I already know the answer.]

Now think about that movement that you can't see while you are operating the boat.

Batteries moving / slamming around is a bad thing!

These are the ONLY battery trays I will install.

Now there are a few things you need to know about them. #1 Do Not over tighten.
#2 Apply silicone grease to the threads....Makes it 4 times easier to turn the wing bolts.

With these it gets the wingbolts out of the way....Sometimes you have to turn a battery to get it out of the hold....Getting stuff out of the way helps......All plastic....No corrosion. When the wingbolts are snugged down.....You can NOT slide the battery in the tray, like you can with straps.

 

[pelagic2530]

It should not be a problem......However.....I run into "Strapped" batteries all the time.

I want everyone that reads this.....If you have "Strape's " around your batteries.....Go see if you can slide them in the trays.....[I already know the answer.]

Now think about that movement that you can't see while you are operating the boat.

Batteries moving / slamming around is a bad thing!

These are the ONLY battery trays I will install.

Now there are a few things you need to know about them. #1 Do Not over tighten.
#2 Apply silicone grease to the threads....Makes it 4 times easier to turn the wing bolts.

With these it gets the wingbolts out of the way....Sometimes you have to turn a battery to get it out of the hold....Getting stuff out of the way helps......All plastic....No corrosion. When the wingbolts are snugged down.....You can NOT slide the battery in the tray, like you can with straps.

Another alternative to Warthog’s trays, which are very good, is this type:
They’re a slimmer fit with fasteners on each end, which helps in some installations. Also very secure. The SS rods on the ends are threaded into lock nuts beneath the tray, so it takes some doing to remove the rods with the tray installed, but it can be done with lock pliers. I recommend snugging those up before you install, so that the rods don’t spin out when you loosen the knobs if you’re removing the battery.

 

[warthog5]

The one above is exactly part of what I'm talking about, as to being in the way....Those metal threaded rods can easily be in the way to remove and install the battery in the compartment.....With having to twist and turn the battery to get it in the tray.
Yes.....Maybe not in "Your" boat? But work on as many as I do and they can be a pain. So eliminating that problem is the answer and why I use the ones I do.

 

[pelagic2530]

The one above is exactly part of what I'm talking about, as to being in the way....Those metal threaded rods can easily be in the way to remove and install the battery in the compartment.....With having to twist and turn the battery to get it in the tray.
Yes.....Maybe not in "Your" boat? But work on as many as I do and they can be a pain. So eliminating that problem is the answer and why I use the ones I do.

And as I stated, there are likewise applications where the width of the one you showed is prohibitive, or access to the fasteners on the sides is impractical. Depending on the installation, the metal rods may not be in the way at all, and even if they are, they’re easily removed with a pair of vice grips.

Just pointing out another option that’s not those garbage strap ones.

 

[warthog5]

Gotcha.

they’re easily removed with a pair of vice grips.

The ones I've seen have a square head on the threaded metal and go into a square hole on the bottom side of the tray......IE: Not removable, not without unscrewing the tray.

 

[pelagic2530]

Gotcha.



The ones I've seen have a square head on the threaded metal and go into a square hole on the bottom side of the tray......IE: Not removable, not without unscrewing the tray.

Nope. These ones thread into a nylock nut that fits into a molded pocket in the base. They can be removed and replaced without removing the base.

 

[Jgro808]

You guys mind providing some links to your particular flavor of trays?

 

[Puck-n-Fish]

Nope. These ones thread into a nylock nut that fits into a molded pocket in the base. They can be removed and replaced without removing the base.

Yup...These are what I have and they work well for my group 31's. I believe they came from West Marine. I ended up taking a router to the top piece and removed about an 1/8" from a couple small ribs to get them to fit perfect over the top of the battery.