Portable battery bank - Are they becoming a real option now

[Smashpjp]

Been Watching the last couple episodes of Sailing Doodles and it has been interesting watching them cruise around the keys and the Bahamas in a Sundancer 340. They transported one of those 2kw lipo battery banks and some solar panels and have shown pro/cons of them effectively.

Maybe we are getting closer, but a larger 6kw would actually be of meaningful use as a genset replacement.

https://www.anker.com/products/a1790?variant=43011257827478

It could run the Air conditioner on a SD340 for 3-5 hours at max charge.

 

[ttmott]

MIssing is the information on the source of the electrical energy.
Sure you can have a massive bank of batteries and large inverter or two, but, where does the energy come from to be stored?
Solar panels? Let's look at a typical 320 watt solar panel on a boat. Because of the limitations on how the panel is installed and times when the sun is available the average electrical production is only around 20 watts per hour average over the typical 24 hours. Let's say you have enough acreage to install four panels - that's only 80 watts of electrical production on an average day.
The numbers are simply not there.
Now let's look to an internal combustion generator to charge the batteries - The interesting thing about generators is they operage only about 30 percent of their capacity over a typical day. With high output inverter-chargers and a battery bank that can absorb high levels of current the generator can operate an near 100 percent capacity for a significantly shorter period or until the battery bank is charged. Key to this is lithium based batteries as they do not require an absorption phase which would blow the generator's run time out of the water.

Now let's look at running air conditioning - we need to look at starting and running. A typical marine packaged AC unit requires nearly 60 amps to start at 240 volt AC - that's a nearly insurmountable 1200 amps of starting current from a 12 volt battery bank. A softstart device is obviously required. Then the run current becomes around 200 amps from the batteries continuous. You can easily see that a 400 amp hour battery bank would expire in just a couple of hours if the AC ran continuously. This doesn't even consider the other electrical demands.

I have fully intended to install a system on my boat so I could run the AC in the cabin over night to get rid of that generator's drone and I still might do that but I'm running into some issues on the system being compliant and insurable. The design is complete but awaiting battery BMS technology to catch up.

 

[The Dark Side]

I got a OUPES 2400 (2234 wh, 2400w, 5000w surge) and use it instead of running the generator. Mainly to plug in fans, blender, electric grill, etc.. I plug the boat (30 amp) directly into the Oupes so I just use the normal outlets on the boat. It will also start and run my 1500w, 16,000 btu air conditioner. Obviously it will not run for a long time, but can run for an hour or so while we are headed back to the dock. These things are getting cheaper every year and I will probably pick up another to double our capacity.

 

[Smashpjp]

I got a OUPES 2400 (2234 wh, 2400w, 5000w surge) and use it instead of running the generator. Mainly to plug in fans, blender, electric grill, etc.. I plug the boat (30 amp) directly into the Oupes so I just use the normal outlets on the boat. It will also start and run my 1500w, 16,000 btu air conditioner. Obviously it will not run for a long time, but can run for an hour or so while we are headed back to the dock. These things are getting cheaper every year and I will probably pick up another to double our capacity.

I think that is mostly the use case I see with these. My air is 16000btu/15A btu as well on the cabin and normal draw is just about 900w.

I have the 8.1s in my 340 and the previous owner removed the genset when he did the manifolds and dripless 2 years prior to me purchasing the boat. Ive had it for over 3 years now and the westerbeke is still sitting in my garage on a stand. Runs fine. There is just some decent effort to get it back into the boat and the battery's rebalanced (They were all relocated to where the genset was).

I do most all the maintenance and its even worse with the generator in the boat. Only 1 time in the last three years have I wished I had the generator and that was when the power went out on Put in bay at 11PM one saturday night. 99% of time we can get shore power at any marina we will travel to or its not uncomfortable with the windows open and a fan or two.

 

[dmorris800]

Slightly different setup (350 Coupe) but figure your AC electric is going to be about 13-15 amps with one zone of AC (16KBTU with the compressor running alot if you are in the TX heat!) plus fridge. That would be 15 amps x 120 Volts x 12 hours about 22KWH. You can't run these batteries to zero so figure 25KWH is what you are going to need plus surge capacity for inrush current. In theory your Anker could do it for about 13K which is cheaper than a new genny not sure if I want to stick my neck out yet. As for charging the only real place would be the dock.

I am always hopping that boat are going to go like the big boats with diesel - electric. I would rather have one diesel Genny and a battery bank than 2 gas motors. Maybe I am just dreaming.

 

[northern]

We have ten 6 volt golf cart batteries and 2500Watt inverter. The generator is 8KW. We spend up to 2 weeks on the west coast where the sun some times does not shine for a week or so. The batteries are in the bottom of the boat. It all seems to work OK. We can go 2 days without running the generator then need to run it for 4 hours to charge the batteries. Batteries last 5 years before I feel the discharge rate is too fast. Your system looks interesting as replacement next time we need new 6 volt batteries. Last 6 volt batteries at Costco were about 100 each.

 

[jmauld]

If your use case is to overnight on batteries and then recharge the batteries with an on-board generator or shore power than I believe the answer is yes. You can build this system today.

If you are trying to ditch your generator completely AND anchor out for a week while running heat or AC then it’s not really feasible for most people.



Financially, It’s more feasible on a smaller express cruiser, vs a larger boat like what TTMott. But you also have battery storage to deal with. You will be shoving batteries in every cabin locker that you have.

 

[jmauld]

I am always hopping that boat are going to go like the big boats with diesel - electric. I would rather have one diesel Genny and a battery bank than 2 gas motors. Maybe I am just dreaming.

Have you checked out the greenline boats?


if you had the coin you could Rip out all of the gas equipment from a Sundancer. Drop in two Nissan leaf or Tesla motors, along with a large battery pack and a diesel genset.

This would really only be feasible if you’re okay tooling around at hull speed most of the day. Probably better to start with a hull that wasn’t designed to plane.

 

[dmorris800]

Greenline looks promising but my only complaint is to many parts. No matter what else I might think of him as Elon would say "The best part is no part". One big genny with battery pack and two electric motors. Less things for me to fix

With our current government and seeing the new EPA rules role out, our days are numbered. I can promise you the amount of CO2 that recreational boaters is so negligible but putting us out of boating for the good of the world will make some bureaucrat feel important / keep them employed.

 

[Smashpjp]

hybrid power train / tiny diesel genset.. Works on Sail.

We all need to much torque and speed for electric power train to work on a cruiser or speedboat. I had a dock neighbor that made the switch last year. Got a steal on a Beneteau 40. Some serious room on that thing

 

[jmauld]

Greenline looks promising but my only complaint is to many parts. No matter what else I might think of him as Elon would say "The best part is no part". One big genny with battery pack and two electric motors. Less things for me to fix

With our current government and seeing the new EPA rules role out, our days are numbered. I can promise you the amount of CO2 that recreational boaters is so negligible but putting us out of boating for the good of the world will make some bureaucrat feel important / keep them employed.

Oh I agree completely. You can get adapters to mount a Nissan Leaf or Tesla motor to a GM bell housing. I assume that would also work for mounting it to a v-drive. It’s a doable project for someone with the disposable income to pull it off. These motors will have plenty of power to get to hull speed, and should be able to manage planing if you can keep them cool enough. The batteries will be your limiting factor for planing. The RPM that they can reach might be an issue For the v-drives.

 

[dmorris800]

Oh I agree completely. You can get adapters to mount a Nissan Leaf or Tesla motor to a GM bell housing. I assume that would also work for mounting it to a v-drive. It’s a doable project for someone with the disposable income to pull it off. These motors will have plenty of power to get to hull speed, and should be able to manage planing if you can keep them cool enough. The batteries will be your limiting factor for planing. The RPM that they can reach might be an issue For the v-drives.

I betcha you could skip the V-Drive and attach them right to the drive shaft. Now you just gotta get Elon to give you the manual to run the motor plus a battery pack...

 

[jmauld]

I betcha you could skip the V-Drive and attach them right to the drive shaft. Now you just gotta get Elon to give you the manual to run the motor plus a battery pack...

The aftermarket figured that out several yrs ago.

Here’s one example: https://www.ev-controls.com/

for that matter. GM makes an electric motor kit that readiky bolts up to a GM bolt pattern. That may be an even easier option.