Electrical: from acid leakage to a new circuit

At some point, every night aboard had started to leave me with a morning headache. Also, when I returned from Sweden, Masha met me. I put some things in a shoulder bag and handed it to her. Ten minutes later, her hands began to burn, and pale stripes appeared on her jumper beneath the straps. Back on the yacht, I found liquid around the battery, blackened wood, rusty tools, melted bags and an acidic smell. It looked as though a slipped restraint and heavy heeling on passage had tipped the battery far enough for acid to escape through a vent.

After watching some YouTube videos about neutralising acid, I bought plastic goggles, a respirator, litmus paper and a couple of packs of baking soda. I covered everywhere I could reach. The liquid hissed and foamed. Once the surface pH tested alkaline, I began washing away the residue and throwing out everything that had sat in the mess.

The batteries were also connected incorrectly. They were two metres apart, but the charger went to both terminals on one battery rather than opposite terminals on different batteries. The second battery looked slightly swollen too. There was really no option but to redo it properly.

#maintenance

Every single day, I read articles about lead-acid, gel, AGM and LiFePO4 batteries: their differences, characteristics, and how to connect and charge them correctly. I read the entire Victron Energy catalogue, started electrical discussions in sailing chats, and trawled Amazon reviews and comments. Three whole evenings went into draw.io to draw the wiring diagram I wanted.

Eventually, I bought a €45 multimeter; two 110Ah marine AGM batteries at €145 each; two battery boxes at €25; two terminal adapter sets at €19; busbars for €31; two junction boxes at €15; three pairs of 50cm, 25mm² cables at €17; terminals for €14; two 1–2–Both–Off switches at €17; heat-shrink tubing for €14; connectors for €10; insulating tape for €8; liquid insulation for €12; three screw sets at €15; 50 metres of webbing for €35; two PVC boards for €10; and a yoga block for €6. About €750 if you know what to buy. I didn’t, so another €150 went on top.

The design has two circuits that can be combined: instruments and engine. The switches allow either battery to be connected or isolated. All the wiring is enclosed, with no exposed conductors. PVC boards reinforce the walls where the batteries are secured, wide webbing holds them firmly in three axes, and a cut-up yoga block acts as a levelling support and cushion. The alternator can connect directly to AGM batteries. Not ideal, as its voltage will charge them to only about 80%, but better than nothing.

The whole installation took four full days. On one of them, Dasha, who lives in Hamburg and loves sailing, joined me. She and her dog Lucky were a great help with the yoga block, straps and cable connectors. One thing worried me: the batteries arrived at different voltages, 12.6V and 11.6V. For AGM, 11.6V is almost fully discharged.

Dasha and I had beef doner boxes with chips and sauce. My treat.

#maintenance

Replacing the solar panel was the finishing touch to the electrical work. The main things I learnt:
– polycrystalline panels are blue; monocrystalline ones are black
– for the same size, blue panels cost about two-thirds as much and produce about two-thirds as much power
– cheap Chinese charge controllers don’t maintain a stable voltage and slowly, irreversibly damage the battery
– so it’s worth splashing out on a Victron Energy MPPT controller
– choose the controller’s maximum current by dividing maximum panel wattage by circuit voltage. I chose a 15A controller, able to handle up to 200W
– panels rarely produce their rated output: expect around 50W from a 100W panel much of the time
– AGM doesn’t like constant topping-up, so you need a switch

I bought a 100W polycrystalline panel for €75, a Victron 15A MPPT controller for €104, a switch for €33, MC4 connectors for €26, ten metres of twin-core 4mm² copper cable for €38, metal strips to adapt the panel mounting holes for €13, an aluminium mounting frame for €35, and M8 bolts and screws for €20. €350 in all.

Halfway through the day, I went for lunch at the restaurant by the neighbouring marina. An interesting dish: two fried slices of bread topped with finely chopped pork belly and a fried egg, with traditional German pickles — cucumbers and cabbage — on the side.

And so August, and the summer of 2023, ended in a flurry of repair work.

#maintenance

I decided to replace the battery. The 30-day return period hadn’t expired yet.

In the morning, I took a trolley to the yacht, disconnected the suspect battery and packed it. I measured both: 13.1V on this one, 13.4V on the good one. A trolley wheel burst as I left the marina, so dragging those 25kg to the bus stop, off the bus, onto the train, back onto another bus and into DHL took some sweating. Sending it was painless: the clerk scanned the barcode I’d taped on beforehand and wished me a good day.

A new trolley and battery went into my Amazon basket. When they arrived, I checked the voltage: 12.6V. Very good. On Saturday, 23 September, I took everything aboard. As the new wiring lets me connect or isolate each component, the plan was to charge the new battery fully, then the existing one, then both together. The first took eight hours and ended at 13.7V; the second, another two hours, ending at 13.6V. When I connected them together, the charger surprised me by running for another two hours before finally settling down.

I didn’t get to bed until three in the morning. Protein bars kept me going. Not for the first time.

#maintenance

Electrics again. First, the starter battery could only be charged using clips. Second, the 7A CTEK Zafir 100 clearly wasn’t designed for a 220Ah bank. Third, charging domestic AGM batteries directly from the alternator is undesirable: the voltage is unstable and too low.

In January, I bought a 25A Victron Blue Smart IP65 charger for €180, plus a battery-terminal connector with a 30A fuse for €10. Connected the charger to shore power, ran the connectors to the batteries, and selected the AGM preset over Bluetooth.

In February, I bought a 2.5m extension lead for the CTEK charger for €14, plus a terminal connector with charge indicator and 15A fuse for €9. That reached the starter battery in the starboard locker. Now both starter and domestic circuits charge from shore simultaneously.

The final wish was alternator charging. In April, I paid €160 for a Victron Orion-Tr Isolated 12-to-12V 30A on the local classifieds site. If only the box alone had been enough. I also needed ferrules and crimping pliers for 0.08–16mm² cable, €34; five metres of 16mm² cable, €22; five metres of 6mm² cable, €10; a 60A fuse, €17; three sets of cable lugs at €12 each; and crimpers for up to 50mm² cable, €23. I already had a 30A fuse and heat-shrink tubing. At least something I didn’t need to buy. Installation took a full day, plus a couple of evenings working out whether an isolated model could be used in a non-isolated installation, and which fuses and cable sizes were needed.

All this helped consolidate my knowledge of marine electrics, especially calculating cable sizes. I updated the wiring diagram I’d drawn earlier. It’s in this post, together with cable-sizing tables for length and expected current. Last year’s version of me would have found it invaluable.

#maintenance