Connect with J/88 Oceanvolt owner?

[danstanford]

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.  

 

[solosailor]

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

 

[danstanford]

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).

 

[JL92S]

Pretty sure they only built 1 OV J88

 

[SEC16518]

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.

 

[jackolantern]

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.

 

[danstanford]

Nope, not that boat. 

 

[danstanford]

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. 

 

[Goatish]

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.

 

[longy]

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

 

[SEC16518]

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?

 

[Snowden]

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?

 

[dolphinmaster]

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 

 

[danstanford]

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.

 

[F18 Sailor]

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.

 

[Arcas]

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...

 

[robalex117]

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.)

 

[danstanford]

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. 

 

[longy]

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.