Denarau, Fiji

By: Kerry

The battery bank: 8×3=24 batteries, each 3.2V for a total of 540 amp hours at 24 volts. Enough, already?

At last! Our new house batteries arrived – only a couple of months late – shipped by sea from China via New Zealand.

Our bank of house batteries – which provide all the power on the boat, from toilets to water pumps to fridges to lights – decided to die back in May. It was to be expected – they were seven years old – but they could have chosen better timing, ie before we left NZ, where it would have been a simple replacement, rather than when we arrived in Fiji, where it was far from it.

We limped through the first part of the season, nursing the batteries and having to run the generator in the middle of the night to keep them charged, foregoing hot water and other luxuries, but it was manageable.

Damian decided – after much research – to go with Lithium ion batteries, rather than replacing the lead acid gel batteries we’d had. It’s very new technology (think Tesla cars) and, it seems, there are no experts out there who can give definitive answers on how to set them up. Certainly there are none in Fiji.

So, as he’s done with so many other systems on the boat, Damian set out to become the expert.

Doing a little ‘soldering-by-YouTube’, configuring the battery loggers

Back in May, he’d teamed up with a fellow cruiser, Mark Silverstein from a cat called Field Trip, who was also replacing his batteries. Over the ensuing months, they both lived and breathed Lithium ion, spending hundreds of hours between them researching on the interweb and sifting through the endless theories and opinions to arrive at a consensus on the best configuration and the requisites of a battery management system (BMS).

The project has rather dominated the season for us, so much so that Sarah, Mark’s wife, and I banned the ‘L-word’ after 5:00pm.

But when Damian finally flicked the switch to ‘on’, we now have around 60% more usable power than we had, for a saving of over 200kg in weight. It means we can run the water maker, coffee machine (let’s get our priorities straight) and just about anything else off the batteries, which are charged by the solar panels, and we no longer need to use the generator.

So we’re doing our bit for the planet: our movement is wind powered where possible and we are now fully solar-powered for our other electrical requirements.

It’s been (yet another) mammoth project, but Damian is deservedly one happy camper.

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