Heating water in the RT27OB

[Submariner]

I came to the same conclusion about leaving the dock with water hot, and keep the hot water tank setting at the highest temp, making it feel as you said, more like a 10 gallon tank.

The temp setting on the output of the Isotherm 6.5 gallon hot water heater is a mixer valve such that scalding water doesn't come out of the faucet. The internal heater and thermostat for the heater is non-adjustable. It's fixed at 167 degrees F. Once I learned this, that's how I came up with the 45 minute timer. I tried 15 minutes, 30 minutes, 45 minutes.. 60 minutes... To see what worked for us.

Having a temp probe on the heater helps in that what if the tank is partially hot, but not hot enough? I don't need to run it for 45 minutes, maybe only another 20 minutes. (if I needed hot water twice in the day, hours apart). The temp probe is not perfect as I can only measure the temp on the output metal fitting, outside the tank. When internal water temp reaches 167 degrees, that output fitting is around 110degrees. I've found that I need to see that temp get to 90 degrees with an outside temp in the 60's, for there to be enough hot water to take showers. It's all relative to what the temp inside the tank is.

 

[T&VBee]

I picked up a Grecell power pack on Amazon for $450 on sale. Regularly about $700. I plug it into the shore power receptacle and run the water heater for about 40 minutes. Then, I charge the Grecell while I am cruising either with the motor alternator or with solar. Charges at about 150 watts. Takes several hours to recharge but that’s ok. No more strain on the house bank of AGMs + inverter to heat water. I like it.
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I picked up a Grecell power pack on Amazon for $450 on sale. Regularly about $700. I plug it into the shore power receptacle and run the water heater for about 40 minutes. Then, I charge the Grecell while I am cruising either with the motor alternator or with solar. Charges at about 150 watts. Takes several hours to recharge but that’s ok. No more strain on the house bank of AGMs + inverter to heat water. I like it.
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That’s very handy, isn’t it? We do something very similar which may be a little overkill but we have all the power we could ever use, even enough for the electric grill, no matter how long we are out. We have an unmodified Northwest Edition R27OB with the stock single solar panel and AGM batteries. We have a Jackery Explorer 2000 with a total capacity of 2,160Wh which fits nicely under the seat/step near the shore power outlet. We simply keep it plugged into a similar pigtail as you have and the boat operates as if it’s connected to shore power. We keep the battery charger switched off but have the breaker for the microwave on, the 110v outlets are always live to power Starlink and other electronics and we run the water heater as needed. Since there’s no need to run the inverter we find the stock solar panel and running the boat is more than enough to keep the engine and house batteries topped off but occasionally when we’re on the hook for a few days we’ll turn on the battery charger if needed.

Here is where the overkill comes in: We also have a small Honda generator we run on the swim step every 2nd or 3rd day or so which simultaneously charges the Jackery and the house bank if needed and we also use this opportunity to heat the water tank. It typically takes less than 90 minutes to charge the Jackery which of course runs silently. We only bring the Honda when we’re out for an extended period with no shore power opportunities available since it does take some (but not much) space. We find the tradeoff to this approach worth it - no need to carefully budget your power usage, no extra solar panels taking away the ability to haul kayaks etc. and no expensive battery upgrades to deal with.

 

[mlanger]

I have an R29 owners manual in pdf format I could send you via email.

Yes! Please do. Boating@marialanger.com

i’d love to learn the real capacities of my fresh and black water tanks, among other things.

 

[Dr Cube]

Hi Martin; our R27 LE 2024 has a total of 560 amp hours of lithium battery storage I believe. If we leave the dock with batteries @ 100%, the hot water tank is cold, and activate the 3000 watt inverter to heat water, do you have any sense for the realistic alternator output of the Yamaha F300 in mitigating battery drainage? We'll assume the inverter would run for about an hour, consuming something like 100 amp-hours or so, without considering alternator output. Have you noted an increase in fuel consumption while the F300 alternator charges the battery bank? Excuse my ignorance if any part of this doesn't make sense, and thanks for your thoughts. RTS14 (Toby Sutcliffe-'Baguette').

Hi RTS14; I just bought a 2024 R27LE as well. I wondering if the 560 amp/hours of house battery is stock configuration or did you add a battery? I have yet to take delivery and can't find the size of the batteries anywhere. Since I'll almost never have shore power I'm having them install an additional 175 Watt solar panel and an additional house battery, but silly me, I forgot to ask how big they actually are.

 

[Fishmagnet]

This solution with a lithium power station has worked well for us. We use it just like Tippetknot has. I installed a battery switch on the output of our solar panel that allows us to switch the panel from the factory solar charger to a victron solar charger dedicated to charging the lithium power station. I built our lithium power station from 2, 54ah lithium batteries and a 2000w inverter. On our 6 week trip to SE Alaska last year we used it several times and never used the gas generator we brought along as a backup plan. During the the off season I disassemble the power station and use the lithium batteries to run transfer pumps for maple syrup production.

 

[Mike and Sarah]

Sounds good. On the R31 you can't turn off the charger (without turning off all shore power) so that's where my concern was coming from.

Watson
I found on our r31 you can turn off the inverter power disconnect (just forward of the inverter in the port lazarette) and that stops the charger also. I can run my BLUETTI connected to the shore power cord and heat hot water without the charge charging the 12 volt house batteries.

 

[watson1987]

Watson
I found on our r31 you can turn off the inverter power disconnect (just forward of the inverter in the port lazarette) and that stops the charger also. I can run my BLUETTI connected to the shore power cord and heat hot water without the charge charging the 12 volt house batteries.

You're right. I forgot about that switch in the laz. I was thinking of just what is available at the breaker panel. Good call!

 

[AG3]

We are about to close on a Ranger 27OB and are considering a Honda Generator. A couple of questions if I may: Where to do store it when not using on the swim platform? The center cockpit floor locker or somewhere else? And secondly, do you store the generator with fuel in it or do you run it dry before storing? Any other info about the generator you think my wife and I should know? Thanks in advance.

We also have a small Honda generator we run on the swim step every 2nd or 3rd day or so which simultaneously charges the Jackery and the house bank if needed and we also use this opportunity to heat the water tank. It typically takes less than 90 minutes to charge the Jackery which of course runs silently. We only bring the Honda when we’re out for an extended period with no shore power opportunities available since it does take some (but not much) space. We find the tradeoff to this approach worth it - no need to carefully budget your power usage, no extra solar panels taking away the ability to haul kayaks etc. and no expensive battery upgrades to deal with.

 

[Dr Cube]

We are about to close on a Ranger 27OB and are considering a Honda Generator. A couple of questions if I may: Where to do store it when not using on the swim platform? The center cockpit floor locker or somewhere else? And secondly, do you store the generator with fuel in it or do you run it dry before storing? Any other info about the generator you think my wife and I should know? Thanks in advance.

I don't have the sage advice of ownership under my belt yet, but we recently closed on our R27LE and I agonized over the generator thing for a long time. We won't have shore power at our dock. Our usage will be a couple days a week. I chose to add another house lithium and another solar panel instead of messing around with a generator. The little Hondas are nice but the downsides are its noise and a pain in the butt of rigging and running it. Our usage will be a couple days a week with overnights. I figure the panels (2x 175Watt) can bring the house back to 100% while were not using the boat. The house batteries with the third lithium will supply about 10KW/hours of energy while we're on it. That should be enough to run everything without being too miserly overnight. If it's not enough then I plan to run the Yamaha. Yes it's inefficient, puts hours on the clock, and only supplies 75A of current. But, it's not as loud as the generator and doesnt require fussing.

 

[Submariner]

If it's not enough then I plan to run the Yamaha. Yes it's inefficient, puts hours on the clock, and only supplies 75A of current.

On an LE, with LFP, you'll get at most, 20 amps from the Yamaha F300 on the dock.

 

[Dr Cube]

On an LE, with LFP, you'll get at most, 20 amps from the Yamaha F300 on the dock.

Is that because it's at idle, or because of some other factor?

 

[Submariner]

Is that because it's at idle, or because of some other factor?

I've spent an enormous amount of time with the R27-OB electrical. Gone through two sets of AGM batteries in 1.5 years, entirely sulfated both sets. I ended up converting my boat to LFP (320amp-hours) almost 3 years ago. It was the most expensive and most complicated upgrade I've made to Channel Surfing. It was also worth every penny for us. My boat's a NW edition with 320amp-hour of LFP and 420 watts of solar.

To upgrade solar and to convert to LFP, my first step was to identify our power requirements. After installing a battery monitor, I used that to create a power management spreadsheet which identifies every load on the boat. I could then enter in how many hours a day I think I'll use those lights, run the microwave, run the hot water heater, leave the VHF radio on, listen to the stereo on the boat, etc... Then it was a math problem to figure out how big of a battery bank I needed and how big of a solar array I needed to replenish the battery. In figuring out what we consume, I also looked at how much engine charging I would get, as measured by the battery monitor.

The Yamaha F300 has a 75 amp alternator. I've not ever seen more than 50 amps off my F300. I've read that this is normal with alternators and to not expect to see 100% of their output. The F300 alternator is a marine alternator, it's designed to give up more amps at much lower engine RPM (which is a good thing for us). At idle, it may output around 10-12 amps. If I bump up the RPM's without putting the engine in gear and get to around 1200 RPM, I have seen about 20 amps.

When I designed the electrical system for my conversion to LFP, I went with an internal BMS on my LFP battery. An internal BMS has no way to know what the alternator is doing. It doesn't know if the alternator is working too hard for too long and is getting too hot, ready to burn up. If it knew that, it could stop the charging, but without any communication between the BMS and the alternator, it would never know. Best practices to alleviate this issue and prevent the alternator from burning up, the DC to DC charger I installed on my boat will do at most, 30 amps. (LFP best practices say to size the DC to DC charger at 1/2 the size of the alternator to prevent it from overheating/burning up). The LE's come with a Kisae DMT1250 for their DC to DC charger. It's rated to 50 amps. If you walk through its configuration on your boat, I suspect you'll find that it's been limited within it configuration to output a max of 30 amps for engine to house charging. I worked with another R27-OB LE owner who confirmed this on his boat. The LE's come with Dakota LFP batteries all which have an internal BMS. I'm also not aware of a way to connect an external voltage regulator to the alternator on an outboard to support an external BMS.

I get 30 amps of engine charging through the DC to DC charger, of which 15 amps is surplus that goes to engine charging, the remaining 15 amps goes to boat electrical loads (chartplotter, radar, VHF, AIS, refrigerator, etc...) The LE's I don't think are any different.

I used to use the F300 as a generator, but have come to realize it's a horrible generator when not underway. An advantage of LFP is that it can take a charge fast. Unfortunately, my boat just doesn't have the capability to provide such a fast charge rate. F300 alternator, T9.9 alternator, 420 watts of solar, and 60 amps shorepower battery charger. That's what I have to work with. My LFP battery supports up to 150 amps of continuous charging. I'm lucky if I can get to 80amps. About 80% of the power we consume on our boat comes in via our 420 watts of solar. On our SE Alaska trip last year, I was seeing a decent amount of engine charging because we were running the boat for 6-10 hours a day. Locally, in Puget Sound/San Juan Islands, our cruises are generally less than 4 hours a day.

I hope this helps. I'd be happy to send you a copy of my power management spreadsheet. It's got a tab for solar, and one for LE, as well as NW editions (and the Channel Surfing edition). I even added in a R29/31 and C30's. It's fairly easy to adapt it to most boats.

We upgraded to Lithium / What it took for us to get there and how they work for us.

Why I upgraded to LFP

Electrical Playlist

Electrical Overview

How does the electrical work on the boat?

www.youtube.com

Website details

House Battery-Lithium | LetsGoChannelSurfing

www.letsgochannelsurfing.com

 

[Dr Cube]

Thanks Martin, that helps explain a lot. I'd seen your youtube video(s) and admired your tenacity at getting the battery monitor and new batteries installed. I really wanted to configure 3 solar panels on our boat. Unfortunately I was told that adding a 3rd panel would require some substantial mods and rewiring, so I'm stuck with the 2X 175W ones. I really hope that'll be enough for us. I know for sure I won't be running the refrigerators when we're not on board. ( And yes, I'd like to have a look at your spreadsheet too )

 

[Submariner]

Thanks Martin, that helps explain a lot. I'd seen your youtube video(s) and admired your tenacity at getting the battery monitor and new batteries installed. I really wanted to configure 3 solar panels on our boat. Unfortunately I was told that adding a 3rd panel would require some substantial mods and rewiring, so I'm stuck with the 2X 175W ones. I really hope that'll be enough for us. I know for sure I won't be running the refrigerators when we're not on board. ( And yes, I'd like to have a look at your spreadsheet too )

With 350 watts of solar and 900 amp-hours of LFP, you'll most likely be fine, but you will want to shut off most loads on the boat, including the refrigerator. This will become especially important during the off-season when solar doesn't work as well. During boating season here in the Pacific Northwest, I usually don't plug into shorepower. I shut off the cockpit refrigerator but will leave my cabin refrigerator on (we use our boat a lot during boating season). If we get a storm that comes in, with 5 or 6 days of rain, my battery bank at 320ah will get down to 30% SOC. So on occasion I'll use shorepower to recharge the battery. But I've gone over a month without plugging the boat into shorepower relying on solar. I do this because LFP doesn't like to be left on a battery tender at 100% SOC over long periods of time. So when I've got the sunshine I use it and just let the system cycle between 75% and near 100%, daily.

The biggest solar array possible on the roof rack of the R27-OB is a pair of 270 watt panels from Custom Marine Products. 540 watts total.
Also recognize that the DMT1250 will take a charge from engine and from solar, both which go to the house bank. But it can't take a charge from both at the same time.

This is is a pair of 270 watt panels installed on an R27-OB LE.

IMG_4070.JPG | Boat-Upgrades {Upgrade Name}

www.letsgochannelsurfing.com

The owner who installed 540 watts installed a dedicated 50 amp solar controller to support solar and engine charging at the same time.

IMG_4141.JPG | Boat-Upgrades {Upgrade Name}

www.letsgochannelsurfing.com

 

[Submariner]

Thanks Martin, that helps explain a lot. I'd seen your youtube video(s) and admired your tenacity at getting the battery monitor and new batteries installed. I really wanted to configure 3 solar panels on our boat. Unfortunately I was told that adding a 3rd panel would require some substantial mods and rewiring, so I'm stuck with the 2X 175W ones. I really hope that'll be enough for us. I know for sure I won't be running the refrigerators when we're not on board. ( And yes, I'd like to have a look at your spreadsheet too )

I don't know what part of the country you boat in. In the Pacific NW, the formula for what to expect from solar is Watts / 4 = amp-hours a day. This is an annual average used to size solar arrays. 420 watts / 4 = 105amp-hours a day, average. Channel Surfing uses about 100amp-hours a day with both refrigerators running, my Cellular router for Internet (remote monitoring and security cameras), and AIS, plus the 24x7 loads. I broke my solar high score this year with 2,730 watt hours (213 amp-hours) during July. The lowest I've seen, cloudy, foggy day, rained all day. 330 watt-hours (about 25 amp-hours a day).

 

[Dr Cube]

I don't know what part of the country you boat in. In the Pacific NW, the formula for what to expect from solar is Watts / 4 = amp-hours a day. This is an annual average used to size solar arrays. 420 watts / 4 = 105amp-hours a day, average. Channel Surfing uses about 100amp-hours a day with both refrigerators running, my Cellular router for Internet (remote monitoring and security cameras), and AIS, plus the 24x7 loads. I broke my solar high score this year with 2,730 watt hours (213 amp-hours) during July. The lowest I've seen, cloudy, foggy day, rained all day. 330 watt-hours (about 25 amp-hours a day).

All great information. Thanks again Martin. I'm super tempted to go with the 540 Watt panels and it sounds like project I'll do next Fall. I'm only leery of stuff that'd require me to pull wires through the hull, not of wiring and hookup itself. The Smartsolar controller seems like a good idea too. Does that require any serious mods?

I'm in the NE In Western NY state, we'll be on lakes Chautauqua and Erie during season. The PVwatts app from NREL ( https://pvwatts.nrel.gov/pvwatts.php ) says we average about 5.4 kWh/m^2/day here during season. Not really great, but not horrid. The Fall and Winter numbers are dismal though.

I too want to keep cellular wireless connection for monitoring and cam stuff. I'm looking at Sierra Wireless' AirLink RV55 4G modem/router. It's very low current and idles at 75mA on 12VDC. The real energy trouble isn't with the router but overly chatty IP devices. I normally use Axis cameras for security things, but they're power hogs so I'm on the hunt for something like a trail cam that'll only trigger and communicate on need.

 

[Submariner]

I normally use Axis cameras for security things, but they're power hogs so I'm on the hunt for something like a trail cam that'll only trigger and communicate on need.

I run a couple of Blink cameras. One inside, one outside. They activate on motion and run on double AA lithium batteries which last about 2 years. I power the receiver (1 receiver for both Blink cameras) off a USB port in the v-berth. Requires very little power, and I can check in on the boat anytime from anywhere with my phone.

 

[Blue Soul]

I run a couple of Blink cameras. One inside, one outside. They activate on motion and run on double AA lithium batteries which last about 2 years. I power the receiver (1 receiver for both Blink cameras) off a USB port in the v-berth. Requires very little power, and I can check in on the boat anytime from anywhere with my phone.

I also have Blink cameras, but need wifi/internet access to connect to them. Am I mistaken? How do you maintain internet service on your boat year round?

 

[Submariner]

I also have Blink cameras, but need wifi/internet access to connect to them. Am I mistaken? How do you maintain internet service on your boat year round?

I have Internet on the boat 24x7. Blink uses it, CerboGX uses it. That's how I get remote monitoring of the boat.

Peplink MAX BR1 Pro 5G router with LTE/5G (Peplink Mobility 42G high-gain antenna).

Internet-Cellular | LetsGoChannelSurfing

www.letsgochannelsurfing.com

 

[Blue Soul]

I have Internet on the boat 24x7. Blink uses it, CerboGX uses it. That's how I get remote monitoring of the boat.

Peplink MAX BR1 Pro 5G router with LTE/5G (Peplink Mobility 42G high-gain antenna).

Internet-Cellular | LetsGoChannelSurfing

www.letsgochannelsurfing.com

Understand. Tnx!