danstanford

Connect with J/88 Oceanvolt owner?

Recommended Posts

I have bought but not yet picked up an Oceanvolt equipped J/88 and I want to extend the range through a portable Honda generator but want to talk to someone who has done this. There are 3 choices and I would like to make the right one for the few times I am ever going to need the extended range. 

2200i watt standalone

3000i watt standalone

2x2200i twinned together.

Ideally I would like to be able to make 5 knots under power basically continuously. The 4x6Kwh batteries on board are supposed to give me about 4 hours of range at 5 knots but I don't know what the math is to determine what I need but I think that would indicate 6000 watts continuously.

Can anyone connect me to someone who knows? Ideally someone with this model of boat.  

Share this post


Link to post
Share on other sites

Does the Oceanvolt charge with 12V or 120V?   The Honda will put out very low 12V as I recall.     Not quite my moms hybrid.

Share this post


Link to post
Share on other sites

In this situation I will be connecting the generator to the battery charger at 120v. The generator has a connector in the face of it which matches the one at the marina (30a marine connector).

Share this post


Link to post
Share on other sites

If the generator has a 30a receptacle it most likely is 240v, not 120v like at the dock......Also, if you tandem 2 2200i units you will be at 240v output.....match the wattage output of the generator to that of the charger.  The charger should be sized to match the output of the ocean volt, to maintain continuous running.

Share this post


Link to post
Share on other sites

Is the J/88 you bought blue?

If so I would go searching for evidence of 12 Metre paint scuffs around it...because that boat was run over by 60,000lbs of aluminum a few years ago.

Share this post


Link to post
Share on other sites
3 hours ago, SEC16518 said:

If the generator has a 30a receptacle it most likely is 240v, not 120v like at the dock......Also, if you tandem 2 2200i units you will be at 240v output.....match the wattage output of the generator to that of the charger.  The charger should be sized to match the output of the ocean volt, to maintain continuous running.

Interesting point but as far as I can tell it is incorrect. Still trying to confirm the 240v part, but for sure the 30a connector is 125v on the companion model and I cannot find anywhere that it says this becomes 240v when they are twinned together. I would think this would be a critical thing for anyone since you connect the two generators together using an umbilical and still just use the one connector. 

If anyone has any input, please jump in. 

Share this post


Link to post
Share on other sites

You cannot put two separate AC power generators in series or parallel to get more power from them, AC is not at all like DC power supplies.

What capacity is your charger?

This will determine what AC power you need. Most battery chargers on smaller boats draw less than 15 amps (AC) at full load (note that chargers are labelled based on their DC output), they are designed this way so that they can run off normal shore power. If you have a monstrous AC charger capable of running off of 30 amp circuit (with a load of more than 15 amps) then you will need to look at a much larger generator that can output that kind of power.

Most likely the 2200i will do the job of charging your batteries, but may not be able to supply sufficient power to actually run the boat constantly.

I have looked into this idea before and thus far have not found a way to make a hybrid that can actually operate off of a small portable generator for long periods of time.

Share this post


Link to post
Share on other sites

The Honda inverter gensets CAN be linked together WITH a parallel cord to double the output amps. Voltage stays the same.

  • Like 2

Share this post


Link to post
Share on other sites
15 hours ago, danstanford said:

Interesting point but as far as I can tell it is incorrect. Still trying to confirm the 240v part, but for sure the 30a connector is 125v on the companion model and I cannot find anywhere that it says this becomes 240v when they are twinned together. I would think this would be a critical thing for anyone since you connect the two generators together using an umbilical and still just use the one connector. 

If anyone has any input, please jump in. 

Yes, you are right....just looked this up.  Why would you want to combine 2 generators vs just buying 1 that is large enough?

Share this post


Link to post
Share on other sites

Isn't all of this an argument for buying one with a conventional diesel donk rather than trying to retrofit a U-boat style diesel electric transmission?

Share this post


Link to post
Share on other sites
1 hour ago, SEC16518 said:

Yes, you are right....just looked this up.  Why would you want to combine 2 generators vs just buying 1 that is large enough?

slinging one off the dock into your mates paws 

Share this post


Link to post
Share on other sites
23 hours ago, Snowden said:

Isn't all of this an argument for buying one with a conventional diesel donk rather than trying to retrofit a U-boat style diesel electric transmission?

Snowden, all of the sailing I have done in the last 2 years could comfortably be done with the electric and batteries with less noise, easier winterization, and it is something I find interesting. However, longer range when needed is the principle objection by most to electric power and in this case I have a 70nm trip to take to get her home so I would like to figure this out in a sensible way. The generator would only be on board when I was headed off on a cruise and don't want to be trapped by wind conditions.

Getting off the dock and out to the starting line is the principle role of this power system and it looks like it will be perfect for that. Sailing is the point of the boat so I hope I never need the generator but it just makes sense to me to solve this problem if I can.

  • Like 1

Share this post


Link to post
Share on other sites

Why not give Oceanvolt a call? I suspect they know the installation, expected current draw of the system and required generator to provide sufficient power for longer duration use.

Share this post


Link to post
Share on other sites

It should be possible; the BMW i3 uses a similar setup with a small gasoline powered generator to power the car for extended range. Of course, it might require a $5000 charge adapter...

Share this post


Link to post
Share on other sites
On 6/23/2020 at 4:20 PM, danstanford said:

I have bought but not yet picked up an Oceanvolt equipped J/88 and I want to extend the range through a portable Honda generator but want to talk to someone who has done this. There are 3 choices and I would like to make the right one for the few times I am ever going to need the extended range. 

2200i watt standalone

3000i watt standalone

2x2200i twinned together.

Ideally I would like to be able to make 5 knots under power basically continuously. The 4x6Kwh batteries on board are supposed to give me about 4 hours of range at 5 knots but I don't know what the math is to determine what I need but I think that would indicate 6000 watts continuously.

Can anyone connect me to someone who knows? Ideally someone with this model of boat.  

I don't have that boat but have experiance with diesel electric catamarans.  Based on the info you supplied you have 24kwh of battery capacity and at 5 knots you use it all up in four hours.  So basic math says you are using 6000watts continously.  Just as you say in your original post.  You need a generator that will put out 6000watts usable.  Its that simple.  

But you would also need a charger that accepts that amount which I doubt the J/88 has installed.  

But from my experiance that is a lot of power to run at 5 knots on a J88.  On a 60' cat we ran a 23kw genset and it gave us about 7knots in calm water.  Adding the 2nd genset, (The boat had two) we would gain about 2 knots.)

 

Share this post


Link to post
Share on other sites

So, I just finished an 18 hour trip with my new boat and she performed perfectly. The instruments said she was using right at 2 kw to cruise at 5 kts which I was just about able to replace with the generator running. It seemed like you could motor at just below that speed continuously running the generator without losing battery power. 

The generator had a 30a shore power type receptacle and I just pushed the shore power cable into that and away we went. Certainly the generator was not laboring and at 3000w I would imagine I could plan to run faster if I could safely up the power through the battery charger. 

The only thing that happened which I should have anticipated was the fact that if you want to run the generator to charge while sailing that angles of heel can be too great for the generator and it will shut down. The other thing I did not do and should have done was either take a friend or figure out the autopilot prior to departure. I had anticipated being able to do that while underway but I could not leave the helm unattended for the duration of the trip to attend to things like this. On the plus side I found that she hoves to just fine! 

Great sailing boat by the way, I was blown away by how high and fast she goes upwind, particularly in light winds and even more as it built to over 9 knts of breeze. 

Share this post


Link to post
Share on other sites

For future trips - your limiting factor was probably the battery charger max output. When the Honda gensets work near thier max they get as noisy as any other unit. Also - if you hang the unit with some rope under the stern rails (or suspended over the foredeck) you don't have to worry about heel or the unit dancing overboard.

  • Like 1

Share this post


Link to post
Share on other sites
8 hours ago, longy said:

For future trips - your limiting factor was probably the battery charger max output. When the Honda gensets work near thier max they get as noisy as any other unit. Also - if you hang the unit with some rope under the stern rails (or suspended over the foredeck) you don't have to worry about heel or the unit dancing overboard.

I did see a potentiometer so I am not sure it that will turn up the amount she will charge. 

Share this post


Link to post
Share on other sites
On 6/23/2020 at 1:20 PM, danstanford said:

Oceanvolt equipped J/88 ... The 4x6Kwh batteries on board are supposed to give me about 4 hours of range at 5 knots

Just out of curiosity what does "4x6kwh batteries" look like on a 29' sailboat. Owner pics. None of that marketing bullshit.

I know LiFePo4 batteries are smaller/lighter than Lead/AGM batteries, but surely you've outgrown the footprint of a standard 20hp diesel? Plus the oceanvolt drive unit is still occupying the space over the saildrive hole. And now you're hauling around a generator and a jerry can full of gasoline that don't have a dedicated space

No argument that maintenance is less with electric. Number of times in a year we run the engine for more than an hour is probably less than two, and we go out at least once a month year-round.

Share this post


Link to post
Share on other sites
16 hours ago, Hadlock said:

Just out of curiosity what does "4x6kwh batteries" look like on a 29' sailboat. Owner pics. None of that marketing bullshit.

I know LiFePo4 batteries are smaller/lighter than Lead/AGM batteries, but surely you've outgrown the footprint of a standard 20hp diesel? Plus the oceanvolt drive unit is still occupying the space over the saildrive hole. And now you're hauling around a generator and a jerry can full of gasoline that don't have a dedicated space

No argument that maintenance is less with electric. Number of times in a year we run the engine for more than an hour is probably less than two, and we go out at least once a month year-round.

Hadlock, nope the batteries live in the engine compartment along with the Oceanvolt power head. It has not outgrown the diesel footprint in any way though I believe it is a bit heavier in the end, somewhere less that 100 lbs. 

For what it is worth, normally there is no generator or fuel required as I motor out from my slip, sail, motor back to my slip with nothing else required. For this use case, the system is about perfect and for the occasional long trip the generator solution is all I need. I am not ready to claim this is a great solution for everyone in every use case, but as methods of generating electricity and storing it grow I do believe this is a great solution. 

Share this post


Link to post
Share on other sites

Perhaps you folks could join me in following this discussion of electric sailboats without the normal outlandish claims of suitability or unsuitability. I wanted to give this a try and I want to make it work both for me and for the next owner of my boat. Crazy claims on either side of the topic don't help at all and for those of you who have decided this is a no-go, I would answer your questions or concerns as a way to learn for myself. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now