Replacing generator with inverter on 330 Express

[everwhom]

The original generator on my 2003 330 Express went kaput this summer and rather than spend money trying to diagnose and fix, I've decided to replace it with an inverter/charger and battery bank. This is for running the microwave or coffee machine for a few minutes at sea, not for running anything high current like the air conditioning for any extended period of time. (In the past 6 years since buying the boat, I've only used the AC at sea once! It's just not much of an issue up here in New England).

Anyways I'm posting my plan for the install in case any others have contemplated doing something similar. Any feedback or critique is greatly welcome!

I'm using a Mastervolt Powercombi 2000w pure sine inverter / 100 amp charger, and will start with a bank of two 100ah AGM Group 31 batteries. I contemplated going Lithium, but I want to attach the aux battery isolator cables from my Yamaha 4.2L F250 outboards directly to the bank to keep it charged and feed more amperage to the inverter when in use, and I know that those isolators were not designed to be used with Lithium.

The other major consideration is installation location -- the bilge area is the obvious choice since there's plenty of space once the genny and fuel tank are removed, but I'm a bit worried that it's pretty wet there.

I'll be doing the work this winter, so still plenty of time for tweaking.

Thanks for any input and happy to take questions!

 

[kirk a]

Following along, as in same situation.

 

[seasick]

Interesting project. I am not sure I would go that route especially since I don't drink coffee
I guess I would have the gen set looked at first but it is probably shot.
Since you are planning on two batteries, I wonder if there is a 24 volt option for the inverter. That will help a lot with current draw and potential voltage drop especially if the batteries and the inverter are fairly far apart. Also ask the manufacturer about your wet location concerns

 

[everwhom]

Interesting project. I am not sure I would go that route especially since I don't drink coffee
I guess I would have the gen set looked at first but it is probably shot.
Since you are planning on two batteries, I wonder if there is a 24 volt option for the inverter. That will help a lot with current draw and potential voltage drop especially if the batteries and the inverter are fairly far apart. Also ask the manufacturer about your wet location concerns

Yeah - mechanic said the electrical side was "locked up" and I didn't want to throw any more money on it. I use it so little that even the annual winterizing maintenance isn't really worth it for me. I literally only use it for a few minutes for quick meals and coffee, and I love the idea of just being able to do that without opening seacocks, firing up the loud genny etc.

Also I figure that in a few years I can replace the bank with lithium and add a whole bunch more capacity if I need it.

re: 24V -- that's a good idea. They aren't as many as the 12V versions, and I ended up going with the Mastervolt because the company has a strong reputation and the Powercombi comes in a pretty small package, unlike many of the other choices. It's pretty new to the market, so hopefully it will live up to the brand name.

 

[SkunkBoat]

Interesting.....hot coffee....hmmmm?

24V system would let you use smaller wire if you have a long run.
Never done that so I don't know what mechanism to use to get back to 12v if you also want to use that bank for 12v House.(would seem to be a waste of weight and battery power to JUST use it for 120 VAC to a microwave/coffee pot.)

Not sure about the 100A fuses on the Aux charging cables. They are 10AWG and supply a charging current from the isolator diode in the motor ...not ever going to carry 100A.

 

[FirstTimeGrady]

Great idea. The battery layout and space on the 330 is horrible, to not have a dedicated house setup on a 33' boat with a refir is crazy. An option would be to only have 1 battery each dedicated to the port/starboard starting motors, to free up 2 additional batteries for the house. Port Engine - 1 Group 31/ Starboard Engine - 1 Group 31 / House - 4 group 31's in parallel (it would not be fun trying to a 4D out of the generator hole.)

This would allow you to run multiple days without having to recharge, running the refir and occasional microwave. Interesting project!

 

[everwhom]

re: 100A fuses on the Aux charging cables, Yamaha sells 2 versions, 1 with expensive 100A breakers and another without anything, so I figured 100A fuses were the right ones. I'm planning to use the Blue Sea MRBF terminal mount ones which are pretty cool because the fuses go right onto the terminal connection and take up very little space with no extra wires: https://www.bluesea.com/products/5191/MRBF_Terminal_Fuse_Block_-_30_to_300A

re: redoing the house bank -- I hadn't really considered doing that. Plan A is to leave the existing battery system alone, but it would probably be pretty easy to move the house to the new bank. I'd have to figure out what to do with the thruster too... Hmmm

 

[ocdansar]

We have to have the genny for a/c on the hook.

 

[doug228]

You'll need a DC to DC converer/charger between the charge leads and the battery. The lithium batteries have super low resistance and will wreak havoc on the charging circuit.

 

[everwhom]

Update on the project!

The install went smoothly and pretty much exactly as planned. This pic shows all the main components.

The view is of the starboard side of the bilge area with the batteries sitting in the spot where the old diesel fuel tank used to live. The inverter/charger is mounted on an added starboard piece similar to how the original battery charger is mounted on the port side. (It's still there -- I didn't touch the existing starboard/house and port battery banks). The main cables to the inverter/charger go slightly off the edge of the frame to the left, but loop right back, so the total cable runs are pretty short -- probably like 4 feet or so. You can see the Victron bluetooth current shunt right next to the main 200A inverter breaker. I'm not sure I really needed that, since I'm pretty sure the inverter will tell me how much current has been run through, but it looked kinda cool. Also, though not required, I added a Xintrex gasoline vapor sensor (the red object with the black round center that sorta looks like a button) at the lower left of the picture, which will sound an alarm and automatically activate the bilge blower if fumes are detected.

I think it's a nice clean install -- even though it's all in the bilge area, the inverter should be safely away from any water, and will hopefully not suffer from any corrosion issues. It's also nicely accessible.

One important note: they actually need to swap where the thick negative cable attaches to the battery bank so that they are connected "diagonally," and also swap where the thinner negative cable that ties to the engine batteries connects. But that should be easy to switch. The reason is that the cable lengths should be exactly identical from the load and/or charging sources for each battery in the bank. Right now the right hand battery has a longer run to the inverter/charger than the left and vice versa with regard to the engine aux charging runs. Otherwise, since electricity will always prefer the path of least resistance, one battery will do the majority of the work and will wear out much faster. For a great explanation of the details (and much more), see Victron's wiring book: https://www.victronenergy.com/blog/2019/09/03/wiring-unlimited/

Definitely a decent amount of work, but the cost is only a fraction of what a replacement genny would have cost, and I will have 1 less internal combustion engine and raw-water thru-hull to winterize and maintain. Also, I expect the next generation of lithium batteries to be much cheaper and more user-friendly, so I will be able to keep upgrading this system as needed. I think within 5 years, a system that can run all the electrics (including A/C) for 10+ hours will be a standard offering. Or maybe they'll finally make outboards that produce plenty of 110 VAC.

I won't be able to actually test the performance of the system until April when the boat is back in the water, but I'm pretty excited for sunrise coffee and toasted bagels at Atlantis canyon this summer!

 

[jip40]

Sub

 

[Hookup1]

Don't write off the lithium batteries especially if you are using a 12-volt inverter. You need to do the math carefully to see if one battery will do it.

I run a 4-bank setup with two house systems. I have charging shunts on both engines to charge each house battery. The engines will charge their starting battery. One of my house battery is a Group 34M Duracell AGM. It's used for bow thruster and windlass. This may work for you for your inverter for short period use like me.

 

[everwhom]

Finally got the boat splashed yesterday, and took it out for a short shakedown cruise this afternoon. The inverter works great - I'm super happy with it. I fired up my George Foreman grill and I was pulling 100 amps in total (about 1000 watts), but 60 of those were coming from the Aux charging leads from my twin outboards, as measured with a clamp amp meter. I have 200 amp hours total capacity, so with the engines idling I can run a 1000 watt appliance for about 2.5 hours without going below 50% discharge (thought a number of sites seem to indicate that you can go as high as 80%). If I have the motors off, that number goes down to 1 hour.

So even with a relatively small AGM battery bank, I can probably even get decent use of the air conditioning depending on how often it's cycling, but I'll have to wait until it's warmer to field test that.

Here's a pic of the final install with the bank properly wired "diagonally".

And also a pic of where the old Fischer Panda used to sit!

 

[Fishtales]

Very cool project.

 

[kees.barfield]

This was my alternative to a gen set on a 2004 Marlin. The DC wire from the battery to the Xantrex Inverter/Charger is 3/0 and probably should have been 4/0 considering the distance/length. It runs the Air for 4.5 to 5 hours when the motors aren't running. Ive had no issues with the Aux Charging wires from each of the F225 Yamaha's connected to the Chins LiFePO 300AH battery. I set the xantrex user settings to charge the LiFePO at 25 amps. It will charge from zero to full in less than 12 hours but it also isnt too much draw for when I do connect a Honda EU2200i to the shore power inlet.

 

[kees.barfield]

Finally got the boat splashed yesterday, and took it out for a short shakedown cruise this afternoon. The inverter works great - I'm super happy with it. I fired up my George Foreman grill and I was pulling 100 amps in total (about 1000 watts), but 60 of those were coming from the Aux charging leads from my twin outboards, as measured with a clamp amp meter. I have 200 amp hours total capacity, so with the engines idling I can run a 1000 watt appliance for about 2.5 hours without going below 50% discharge (thought a number of sites seem to indicate that you can go as high as 80%). If I have the motors off, that number goes down to 1 hour.

So even with a relatively small AGM battery bank, I can probably even get decent use of the air conditioning depending on how often it's cycling, but I'll have to wait until it's warmer to field test that.

Here's a pic of the final install with the bank properly wired "diagonally".

And also a pic of where the old Fischer Panda used to sit!

One 200AH LiFePO battery will likely double the time you can run the inverter and you will likely replace those AGM batteries 2 or 3 times before a LiFePO will need to be replaced so with a little more upfront cost you will save in the long run. And the LiFePO can be charged really fast if you want to set the inverter charger to a higher charge amperage.

 

[everwhom]

I read from various sources that one shouldn't connect the alternator output directly to a Lifepo battery because if the battery management system in the battery suddenly disconnected the battery from the circuit, the alternator could be damaged. Instead they advise using a DC-DC charger such as a Victron Orion or similar... In the end I decided that by the time I need to replace my AGM's, the lithium battery systems will probably have advanced another generation, so I'll worry about it then!

 

[Angler Management]

I'm doing this too this winter or spring. Considering adding a diesel furnace for use with the diesel tank for the now trashed genny.

 

[Angler Management]

Also, may I recommend small stove and french press for coffee... better than coffeemaker!

 

[kees.barfield]

I read from various sources that one shouldn't connect the alternator output directly to a Lifepo battery because if the battery management system in the battery suddenly disconnected the battery from the circuit, the alternator could be damaged. Instead they advise using a DC-DC charger such as a Victron Orion or similar... In the end I decided that by the time I need to replace my AGM's, the lithium battery systems will probably have advanced another generation, so I'll worry about it then!

I dont think this is an issue because Alternator output is still connected to the cranking batteries. Issues would occur if there was no place for the output to go.