Hello, welcome, come aboard! This instalment of Sailing Longo Maï comes from the pen of the El Capitan and Wizard of All Things Technical: Ian. (Italicised notes are from Malia because she can’t help herself):
We’ve had a bit of a geek out on our electrical system. Please don’t read any further unless you’re into boat electrical and /or geek stuff. (I think it’s a good read for anyone. Unfortunately, I now know so much geek stuff that I am questioning the evolutionary pathway from luddite to geek and whether it’s possible to voluntarily regress.)
We had a 580ah house battery system which should have been ample for our needs. However, we were finding that if we sailed through the night (no solar or engine charging) in rough weather and the autopilot was working hard we were excessively draining the system. At times we had to turn the fridges off to conserve power. So, the situation needed to be fixed. (Ian has called the autopilot – Brittany Steers. And no one likes warm G&Ts hence the original necessity to remedy the situation.)
Based on observations of our current system 600ah of lithium batteries should be an OK solution. The advantage of lithium is you can discharge them to 10-20% whereas you should only use about 50% from a conventional battery. Then we had a few beers and decided 800ah would be better. No one ever complains about having too much power. (I didn’t have beers? When were beers had? Were these beers with your salty sailor buddies? Why wasn’t I invited? – mind you I don’t even like beer but it would have been nice to be asked to the lithium party.) (It was man business!)
After 10 minutes on the interweb it became apparent that the change to lithium is a bit more complicated than just dropping in new batteries. So, before I got started, I figured it was worthwhile taking a good look at the current system. It should be in pretty good shape since we had a ‘full’ survey by a licensed surveyor prior to purchase. After about another 30min on the interweb I felt a suitable level of expertise to audit our system.
Well. The more I looked the more I found wrong or at least suboptimal with our system:
The battery bank contained different size batteries (nope) which were parallel wired through one battery (nope). This means the first battery takes most of the load and ages prematurely. This then drags the whole system down. It is probably the main reason why we had under floor heating and such poor overall system performance. (As is always the way one poor sod does all the work and when they are worn down by the load the whole system fails! Sounds like every workplace I know.)
There were also no covers on battery terminals (nope) and no fuses (whole lot of nope). There’s a lot of energy in this system and this represents a serious safety issue. (If you accidentally stepped on the suckers, we’re talking not just an unintentional perm but the smell of roasting meat)
The batteries weren’t secured (nope). The boat tends to move around a bit and having the batteries secured is the industry standard.
The cabling couldn’t have been any worse (again a whole lot of nope here). Open ended cable lugs were used instead of closed ones which prevent moisture ingress. The lugs were hammer crimped instead of hex crimped. Insulation tape was used to seal some of the lugs and where proper heat shrink was in place it wasn’t heat shrunken. The cables were mismatched and inadequate for the amperage and length. Also, automotive cables were used instead of tinned marine cable which is not the end of the world but they’re not going to last very well. Put all this together and it explains why there was evidence of corrosion inside the cabling.
I’m taking this as bit of a lesson on paying ‘experts’ to do work on your boat, or at any time really. The previous owner would have paid full retail prices at Port Corbières, France, for a self-proclaimed expert to install a battery system. What he received was something the work experience kid could have done a better job after five minutes on google. It’s almost like every opportunity to cut corners and do the wrong thing has been leapt upon with wanton glee. Good thing we paid a professional surveyor look at the boat before we bought it!
The lithium system batteries are individually fused and connected to a busbar using equal length cables. The busbar is then protected by a class “T” fuse. It’s charged by 2 Victron Smart Solar Controllers and a Victron DC-DC Converter which enables charging from the main engine without overloading the alternator. We also installed a Victron Shunt, which measures the capacity of the system and how much power we’re using. (Two things – Firstly the class “T” fuse is thus called because if ever it blows, we will be saying “Thank God (and Ian) for that Thing. Lastly – All the nifty Victron devices are blue toothed so Ian doesn’t have to guess or open up the bilge to see what is happening, so that’s nifty!)
Now that we have the new system installed, we can tell how much power we have and how much we’re using. I think we’ve overachieved a little and now need to find more appliances to justify the cost of the installation. (Happily, this means we can use our fan at night. Ian wants sensible things like a microwave, but Janie R has taught me they are the devil’s appliance and I no longer see the need. I’m getting me a hairdryer and a hair straightener and air-conditioning and if I can find the space maybe I can convince Ian to buy a coffee machine?)
Here’s some before and after shots our batteries:
Finally, because I like to have the last word and because I need to say out loud just how wonderful Ian is and how hard he has worked on this and the many other projects he has completed over the last few months. Ian knew almost nothing about batteries and wiring until a little while ago. Between the interweb and many conversations with fellow salty sailors (special shout out to Phil E and Steve N), he has gone from novice to expert in a very short time. In doing so he has saved us money, improved our quality of life, and most importantly saved our lives (the last system was a disaster waiting to happen). He is now paying forward the learning by helping others looking at doing the same thing. While undertaking this project he has also project managed and/or completed the other work that needed to be done on Longo. Much of the time battling the language barrier; he has become the master of interpretive dance and technical drawing. On top of all this he has made sure I have been gainfully employed in projects big and small; increasing my knowledge and usefulness as crew. He’s also put up with my occasional whine about not being “out there”. So, I cannot express just how much I love this man and how grateful I am for his commitment, patience and willingness to learn. He is an example to me and all that meet him. However, he is a god to the tortoises, only.
Sailing Longo Maï 