Electrical upgrades

This was the most time consuming task I have done on this boat so far. To install the solar and a motor battery charger, battery monitor and the depth & speed instrument, it took me some weekends pulling cables behind carpeting and various fiberglass layers. I had to use almost all tools I have and weird body positions to sort out this task by myself alone.

First, I had to pull some wires from the cockpit lockers into the distribution panel for battery charging, monitoring and also for the depth sounder, but I will write about this later, because it deserves its own post.

pulling cable from the aft-berth...

...into the head room and then right...

...to the distribution panel

all wires were then hot-glued onto the hull behind the carpeting

Then I've installed the "real" battery monitor Victron Energy BMV-700 which is really great in giving you precise information about the charging/discharging, battery voltage and even the remaining capacity. I've installed it instead of the car lighter socket next to the switch panel.

drill the hole

insert the monitor and simply plug in the cable from the shunt

this the example of properly labeled cable with transparent heat shrink

This is the original wiring behind the switch panel. They are using ordinary and cheap DIN rail-mounted system used for home installations and I believe this is not marine rated. Maybe this is suitable for freshwater environment, but we will see what happens on the sea. If there will be a problem with corrosion I will replace this.

factory wiring using the ordinary DIN rail-mounted system

Then I've replaced the simple analog gauge battery monitor, which was mounted in a strange position to look at anyway, by the 12V car socket. I cut a thin piece of oak to hide the original cutout.

Now get back to the cockpit lockers. Here I've installed the main electrical subsystems. The junction box in the middle is the combining the output of the solar panel and the outboard charging coil. The connection is pretty simple - solar panel has there blocking Schottky's diode to prevent the current from the motor going into the solar cells and a fuse. The outboard motor has the bridge rectifier and the fuse already installed inside the motor so there is no need to add an additional blocking diode or fuse. And finally the MPPT charger has the fuse for the battery already inside.
On the right you can see the battery monitor shunt and bellow there is a main fuse housing.

battery charge, junction box, battery shunt, main fuse

The final complaint about the wiring is the cheap and poorly crimped ring terminals on this main 10mm2 cables. I was almost able to pull out the cable from the terminal!!! Anyway, I've crimped better quality terminal with the proper crimping tool and used the heat shrink to prevent the corrosion.

proper wire terminals

There is still a plenty of space for the main battery charger from the 230V power line. I've bought the smart CTEK M200 charger. This is a marine rated, quiet and very easy to use charger.
We don't have power line sockets on our boat so I will simply use the extension cord and put it into the locker.

Solar panel mount

We would like to use a compressor fridge on our boat, but that needs some power from the batteries. I've already installed the new charging coil in the outboard, but still we need more power especially during the sunny days. So we decided to install the solar panels around 50W of peak power. On the previous boat we had the solar panel mounted on the top of the cockpit arch, but this small boat does not have it and we don't plan to install it.
The best flat location is the area in front of the companion sliding hatch board so I will give it a try.
There could be just one more issue and that is the shade from the boom. The problem with the solar panels is that when only one solar cell is in the shade or dark the whole current of the panel is degraded. This is why I don't want to mount the panel permanently (I mean new holes in the boat) at this moment. Polyurethane glues are pretty hard to remove so I've searched the net and found the 19mm 3M VHB acrylic double sided tapes 49xx series which are UV and weather resistant.  Declared holding strength is around 6kg for 30cm of the tape which should be enough, since I will use 2x 40cm on the aluminum L-profile which will then hold the 5kg solar panel.

At first wanted some cool marine flat solar panels that could fit the desired area, but they are pretty expensive, but finally I bought the Victron Energy SPP51-12 50Wp polycrystalline panel with the dimensions of 540x670x35mm. As the charger I bought the Victron Energy BlueSolar MPPT 75/15, not cheap, but the best thing about this is that its all encapsulated electronics and suitable for marine use. This charger will be used also for the outboard charging and will be mounted in the new battery compartment in the cockpit.

Here you can see some photos of the installation itself.

back of the panel with the 2x2cm L-profile rails 40cm long and 3M tape installed

deck connected - 3 terminal (4x 1mm2)

Man, cables from the distribution panel to the mast step is almost impossible to pull through. The inner fiberglass is on some places mounted together with the outer skin so tight that it's impossible to install new cables here without drilling some kind of inspection holes. Luckily I was so wise and ordered 2x double line cables as a spare. Factory installed 4x 1mm2 which is too narrow diameter for the DC currents from the solar panel without significant voltage drop. So I put them together in parallel so the final profile is 2x 2mm2. Then I was able to install the 2,5mm2 cable from the distribution panel to the battery behind the carpeting which was not that easy anyway.
The boat is nice as you don't see any screw heads and all looks clean, but installing something additionally is a pain.

cables to the deck connector on the left (on the right is for mast lights)

final connector glued with sikaflex

final placement

screws holds the panel in place

The holes for the M6 screws are just tapped in the aluminum panel frame so the panel can be easily removed and stored inside the boat.
The future will tell how good this installation is but if not, I can move it to somewhere else, probably stern rails, and use the second mast connector for anything else.

Updated 5/20/2016: I've found out, that the deck connector was some kind of a fake cheap copy which lasted only one season. Its contacts totally corroded so I've replaced it. See my upgrade of the solar panels here.