Sailboat in storage

DIY
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1

A friend of mine has bought a sailboat in Italy and is currently in Greece. There the boat will be in storage outside on the shore.

On my advice he has installed 2x 100Ah lifepo4 batteries, a victron mppt charger, a victron bmv712 shunt, a Orion 12-12-18 charger.

During sailing everything works perfect.

His question now for me is about keeping the batteries connected to the solar panel mppt charger to keep the batteries charged and the time or to disconnect everything during the period of absence.

The YouTube video of Will Prowse was clear. Keep the batteries charged at 100% most of the time for lifepo4 batteries.

My question is about the starter battery.
Is there any possibility to keep the lead acid starter battery fully charged using the Orion charger?

2

Which battery does the mppt charge.

Which battery is the input to the Orion and which is the output.

3

The starter Battery with engine and alternator is on the input side. The lifepo4 with mppt is on the output side of the Orion.

The Orion starts charging the lifepo4 with running engine.
The mppt is charging the lifepo4 with solar panel during daytime independently from the Orion.
There is no cerbo gx or other intelligence

It is fairy easy to switch the cables on the Orion for reversing the direction but then the charge protocol needs to change from lifepo4 to lead acid.

4

2 options, both will work.

  1. Swap the MPPT to the starter battery in storage. You may need to adjust charge parameters.

  2. Swap the Orion cables over, again you may need different settings.

5

Thanks for your quick reply.
Very helpful.

An extra Orion 12-12 might be possible as well i think. Not sure if it can stay connected all the time. (Normal sailing usage and storage usage)

For now (he will be away for 2-3 months) the starter battery will be disconnected.

For winter time i have suggested a small extra solar panel for the starter battery only. That might be the easiest setup i think?

6

Hey, good question!

I usually say that there are two approaches. Each with their own benefits:

  1. Keep them charged with solar or something.
  2. Charge full, and then disconnect. Make sure to really disconnect. Don’t leave any small loads like a batterymonitor connected.

Leaving a fully charged battery for a while, at a minimum 6 months, should be no issue for any lead or lithium battery.

7

Another Orion could work with a switch on the remote terminal.

A small solar panel.with a basic pwm charge controller would also work and avoid messing with the rest of the system.

You can also get trickle chargers such as this one, German so available in Europe even though I have added a UK link.

1 Like
8

Thanks to you both.
@mpvader @pwfarnell