Puerto Viveiro

Highlights – the overview

We are going to be in Viveiro for more than a month. It’s a safe place for Dione IV while we travel – visits to the US and the Netherlands to visit family. In addition to some fun social gatherings with our cruising friends, there are projects to keep us busy. First, there is project “Super Scooter”, where Wim has put together a plan to add an external battery and increase our power and range significantly… boldly going further than the scooters (Thelma and Louise) have ever gone before!

Next, the aft part of the lazarette needs to be finished and a shelf added… a big job for Wim while Sher travels to visit her Mom.

But there’s also time to relax with a lunch on “Antares” and an invitation for a party on the “Celebes”, a Dutch yacht on our pontoon. We have a great time with delicious food and drinks and nice conversations!

Meanwhile, Sher is enjoying her time with MomCat in the USA

One more project to add to the list… Louise (Sher’s scooter) had a bad rear tire, so we ordered a new one from Amazon and Wim replaced it. Here, with that battery compartment open, motor wires disconnected and rear wheel disassembled.

And then, back to finishing the lazarette. All parts are finally mounted around the exhaust, and the shelf is installed! It looks fantastic, but we’ve lost some space in the process.

Then, we’re stuffing everything back! Of course, the smallest one and the one with the best organizing skills has to go in there 🙂

A 100% filled lazarette…

Now it’s time to take a break while we travel to the Netherlands to visit Wim’s family!

The Captain’s Log (T+245, 246,…263) – the complete story

Project “Super Scooters”
Aft Lazarette
Maintenance on Louise (Sher’s scooter)

And now for Wim’s experiment with external batteries for the scooters. Parts have arrived (thanks Amazon!) and project “Super Scooter” begins!

The challenge is to “trick” the scooter’s internal battery. Swapping batteries is impossible due to the fact that the scooter’s battery communicates with the BMS in the scooter controller. So, when we disconnect it’s battery and connect an external battery, there will be no communication and the scooter will surely stop on an error. So, the only possibility is to connect an external battery parallel to the scooter’s own battery.

But this needs some care… Connecting different kinds of batteries will result in an uncontrolled discharging the battery with the highest voltage and uncontrolled charging of the battery with the lowest voltage. With uncontrolled, possibly very high current. This is very dangerous for lithium batteries and will surely result in fire. So, the current has to be controlled, limited.

Another issue is, once we charge with a limited current, the voltage shouldn’t be too high. Because when the scooter detects a higher voltage than the battery, it thinks it’s charging. And during charging there’s a drive inhibit: it switches of the motor for safety reasons. So we will have to control the voltage, too.

So, we connect an external battery parallel to the scooter’s internal battery via a current and voltage controller and thus ‘trick’ the scooter’s system.

Let’s say we keep the internal battery fully charged. 100% SOC (State Of Charge) = 54v. So, we tune our controller to 54v. That means, when the motor takes current out of the scooter’s battery, the voltage will drop below 54v and a (limited) current starts flowing from the external battery into the scooter’s battery. When it reaches 54v again, the current will drop to zero. Like this, the scooter’s battery stays full until the external battery is empty. Hopefully the scooter’s system will not make objections… We have to do an experiment first, before investing in batteries…

This is a step-up DC-DC converter with a regulated voltage and a regulated current.

This is the battery for the test. An 18v lithium battery from our power tools.

We will have to know what’s happening and we will have to monitor the external battery. This little display measures the current via a Hall-sensor and measures the voltage. It can calculate the SOC (State of Charge) of the battery.

A test setup. We increase the 18v from the Festool battery to 48v for the scooter battery.

So far, so good.

February 20.

Now, we have to make a connection parallel to the scooter’s battery. For that, we have to open the battery compartment.

First, we remove the rubber mat by heating it with the hot air gun to make the glue release.

While Sher heats, Wim pulls the mat.

That came off really nice.

After removing numerous screws we see the battery and the system controller.

Disconnect the battery.

And make the parallel connection cable.

A nice watertight power plug from Victron.

Battery compartment closed again.

Now, tape the test setup to the foot board for a test ride.

We decide against maintaining a 100% SOC of the scooter battery. Namely, when we go downhill and the motor regenerates energy from braking, the energy has to go in the scooter battery. It can’t go back into the external battery because the DC-DC converter is one way: from the external battery via the DC-DC step-up board to the scooter battery. So, the regenerated energy can only go into the scooter’s battery. And when that would be 100%, it would over-charge. And that is dangerous. So, for now, we decide to maintain 90%. That will give us 10% room for regeneration. A long downhill track never regenerates more than 10%. Maybe we’ll change that level in the future.

Wim takes a short ride to bring the SOC to 90% and we measure the voltage: 52,7v.

We set the (still disconnected-) DC-DC converter to 52,7v.

Then, Wim takes a longer ride. Full throttle, uphill. That brings the battery down to 70%.

Then, Wim connects the DC-DC converter to the scooter’s battery and slowly increases the current to 2A. The 18v Festool battery is now charging the scooter. We even see the scooter’s SOC display go up! That’s good because this means the SOC is calculated from the voltage. And not from any other intelligence (the communication with the battery’s BMS). This makes it easier to trick the system.

Reason for a smile!

Another ride. A few km’s, not uphill. Yes! Wim left the marina at 79% SOC and it stays 79% for a long time. That means, the Festool battery is powering the scooter. Well, after half an hour the SOC starts dropping: the Festool battery is empty. Back to the boat. Change the Festool battery for a fully charged one. Let’s increase the current to 5A, Wim thinks. Oops, everything shuts down. There’s a 15A fuse at the input of the DC-DC converter and that has blown. Of course, stupid! 52,7v at the output and 18v at the input is a factor 3. So, 5A at the output is 15A at the input! Well, replace the fuse, go back to 4A and everything works fine again.

This looks promising! Powering the scooter like this is no problem for the scooter. Tricked! 🙂

Now, we can order a bigger battery. Although Wim would like to have a LiFePo4 battery, they are too big and too heavy. We’ll have to stick with NMC-type batteries like they are used in e-bikes and scooters. We select the biggest one available in that category: 60v/30Ah. That is 1,8 kWh of energy. 4 times more than the scooter’s battery (which is 0,48 kWh). This will extend our range greatly! It weighs 6kg’s and will fit in a small case that can go on the rear of the foot tray of the scooter, behind the saddle. And 60v means lower current. We have to change the step-up DC-DC converter into a step-down type but that’s easily found on Amazon.

February 21.

In the early morning, Sher leaves to A Coruña airport to take a flight to the USA to visit her mom. Coincidentally, the German guy of one of the boats on our pontoon has to go to A Coruña to bring back his rental car and Sher can have a ride with him. Very convenient, because by public transport it was impossible to get to the airport at 8 ‘o’clock. Thanks, Philipp!

During the day, some stuff we ordered on Amazon arrives at the marina office. Amongst it are the small cases we’re going to use for the scooter’s external batteries.

They are imitation Peli cases. They are cute!

February 22.

Sher has safely arrived at MomCat after a 24-hour travel.

Wim starts installing the displays in the small cases. The air release knob has to go but we’re not going to need that.

Ready so far. Now, we have to wait for the batteries to arrive. They come from China and that’s going to take a few weeks…

February 23.

Wim:

In the back of the lazarette, under the aft deck, is a space that is not finished. It needs some carpentry. Pfieuuw… This has has been on the to-do list as a low priority for years! But now is a good time to pick-up that job: while Sher is in the US, I can make as much mess as I like! 🙂 Because everything that is in the lazarette has to come out to reach this area (and that is a lot!), the boat turns into a big mess. And all electric tools and sheets of plywood needed, make it even worse. And then there’s the dust from sawing and sanding. I don’t mind all that: I lived for quite a while in such circumstances when I was building Dione IV’s interior.

The Port-aft cabin used as temporary garage…

A bunch of crates blocking the corridor to the shower/toilet…

Stuff under the salon table.

All the stuff that can handle rain goes into the cockpit.

Now that the area is reachable, the first thing that has be done is replacing one of the connectors for the solar panels. That broke about 2 years ago and had been on the low-priority list since then…

Now, I can can start with the woodwork. I spayed the PU-foam last year already.

Badger is a great little helper! In return for some beers he goes into into places I can’t reach! So I have to go to the supermarket again to buy some more beer…

In the evening, there’s an invitation for a party on the “Celebes”, a Dutch yacht on our pontoon. We have a great time with delicious food and drinks and nice conversations!

February 25-27 – Puzzling pieces of plywood together…

The brown-colored wood is outdoor quality Meranti (hardwood) plywood that I had on board since The Netherlands, the white-colored wood is indoor quality Poplar (soft and flexible) plywood that we bought at Bricomart in Avilés (regretfully, they didn’t have outdoor quality). Of course, this is all indoor. But, in case the wood gets wet (for instance from condensation), the layers of the indoor quality plywood will disintegrate. But, because of the 8cm thick foam insulation, there won’t be condensation so we can use this kind of plywood without a problem.

I have to fill some spaces with foam, for insulation. I don’t have enough spray cans (bought in The Netherlands) so I order some cans on the Spanish Amazon. It arrives next day! And the foam is amazing! It slowly (over 2 hours) expands to a huge volume! Very different from the stuff I had, that hardly expanded after spraying.

February 28 – All wood work finished now.

The parts that cover the exhaust are removable, in case the exhaust needs repair.

Also, there is a small hatch at the left side of this picture that gives access to the cable tray.

In the middle of the cabinet is a removable shelf.

All bits and pieces left over from sawing the puzzle pieces.

March 1.

A cable tray to protect the starter battery cables was missing. Gluing it over the cables needs some creative temporary support constructions…

All wood coarse-sanded, excess glue removed and seams filled with MDF filler.

During the construction of Dione IV’s interior, I have used more than 20 kinds of filler. Till I discovered this MDF Filler from the brand “Albastine”. It’s a wood-like water-based paste, easy to sand down and it stays flexible after curing. And the flexibility is the most important feature: because I use it on seams, edges and corners. And that’s where little movements are when Dione IV’s steel hull flexes under high strains during sailing. All other fillers cracked but this one flexes with the movements of the hull. Great!

Meanwhile (from February 22 to March 3), Sher is enjoying her time with MomCat in the USA

March 6.

After 3 rounds (1 round per day) of sanding, filling, sanding, filling, sanding, filling and sanding:

The removable parts and part of the hull timber painted with the first layer of primer.

And, the new cabinet painted in the first layer of primer.

March 7 – Maintenance on Louise (Sher’s scooter)

She had a soft rear tire and when we tried to inflate it, it turned out that is was leaking. We discovered a tear that couldn’t be repaired so we ordered a new tire on Amazon. Today, we’re going to replace it and while the battery compartment is open for disconnecting the motor we will connect the wire for the external battery.

Battery compartment open, motor wires disconnected and rear wheel disassembled.

Oops, the tire is really bad! All around, the sides are completely destroyed and teared. A while ago, we discovered that all tires were too soft and we inflated them to 3 bar. But obviously, Louise has been driving too long on a soft tire…

We already know that replacing the heavy tubeless tire is going to be a tough job. Wim watched a YouTube video about it and the guy in the video had a very hard job! In the end, he even had to take it to a garage…

So, we have bought a brutal tire levers set for this job. Well, it is really a hard job! Wim has to use all his force to get the old tire off and even more force (and expletives…) to get the new tire on. Regretfully, the rim suffers some damages from the heavy tools but when inflating the tire it’s all good. Pfieuuwww…