23 Feb #5 Energy Storage
In order to sail around the world self-sufficient, we had to determine how to store the energy generated. On board, many devices are electric, which we use at different times during the day. For example, there are times when we generate more than consume, but also the other way around. To make a correct estimate of the amount of storage we would need, we have outlined different scenarios in advance how to live on board. It made it clear that with our lifestyle and our budget we had to choose a combination setup of normal AGM batteries and a set of Lithium batteries.
The first battery bank is a 12V system consisting of 4 x 220Ah Victron AGM batteries. These are switched in parallel. These batteries are linked to the 12V onboard network and a combination inverter to make the 12V 230V. We put the batteries in the old diesel tanks. We made the existing lids bigger, so that the batteries fit in and eventually got stuck well. Because the batteries are further maintenance-free, we no longer have to be able to access it easily. After 3 years of intensive use, we notice that capacity has deteriorated. But they are still good enough to be able to sail back to the Netherlands from New Zealand.
The second battery bank is a 48V system consisting of 4 x 48V Pylontech Lithium batteries. These are built in series, with its own BMS (Battery Management System). The BMS controls the batteries and monitors batteries against overcharging and excessive discharge. There is also an inverter attached to this system to make of 48V 230V. This allows us to continuously generate 3000W and temporarily 6000W on board. This is similar to 1 group in a household and this is enough to cook with induction on board, for example. The batteries are placed in an old cabinet, so we can easily access it. These batteries can be put on and off by hand. So far, we have turned off the whole row of batteries once, during severe thunderstorms at sea. Furthermore, we notice that the capacity of the batteries is almost the same as before departure and we are therefore very pleased with the lithium batteries on board.
The two inverters of the different battery banks are linked together, so that the energy of the two battery banks can be divided among themselves. Once there is a risk of energy shortage at one, the energy can be distributed between the two battery banks with a simple dial.
The last battery bank is a 24V system, consisting of two batteries for the anchor winch. We charge these batteries from the 48V battery bank. These are also AGM batteries, so we don’t have to do maintenance here either.
In order for all electrical systems to come together, we have created our own power cabinet with each battery bank. We placed the power cables of the batteries on a large copper strip. Through this copper strip, both alarm clocks and all consumers come together. I also strongly recommend that everyone start early with a large distribution/power cabinet, to keep the overview. Because in order to eventually get everything electric on board, a lot of wires come together.
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