The wind veered further south early in my watch requiring a change to the Hydrovane setting to ensure we continued to track a course of about 260° which we hoped would avoid the lightest of the light winds forecast further west in a couple of days. For now though Bonny continued at a reasonable pace of around 5.5 knots.
The sky is overcast - not great for solar charging but by 1230 our batteries had recovered from their morning low of 30% to 46%. I think they should reach at least 50% by the time the sun is obscured by the shadow of our sails later this afternoon.
In the event the batteries charged up to 56% of their capacity, 1% less than the day before. Their total capacity is 200 Amp hours, all of which is available thanks to the Batteries being Lithium.
Another grib forecast would be useful to help us navigate around (if possible) the area of previously predicted calms ahead.
Given our recent previous experience of operating Starlink on the ocean it may take 4 hours before we manage to get a connection which will consume about 16 Amps. Amps and fuel management will be important over the next few days therefore. There's no point in running the engine for any longer than necessary for sufficient charge to get us through the passage or even the next few days.
The fridge is the main constant drain on the batteries and consumes about 22 Amp hours a day with other bits and pieces (raspberry pi computer for navigation and weather downloads, VHF Radio, AIS transceiver, navigation lights, compass light, cabin lights, charging phones and tablets) accounting for about 36 Amp hours a day.
In addition when we run the watermaker that consumes about 6 Amps. Currently we're running it for about 45 minutes every other day to produce 4 litres of drinking water. So a rough daily equivalent is 2.5 Amp hours a day.*
We haven't run the water heater on this passage, partly due to the power problems but also because, in these temperatures and given the fairly warm ambient water temperature of the water in the water heater tank, there's no great discomfort to have a 'cold' shower. Indeed it is rather pleasant!
So on average (not counting Starlink) we're using about 60 Amp hours every day. Therefore that's how much power we need to generate to keep up with demand. As mentioned above, by the time the sun had stopped charging our panels yesterday afternoon our batteries were up to 56% of capacity.
Clearly, over the duration of the passage so far (we started it with our batteries fully charged), charging has not kept pace with consumption. That's despite running the engine for 4.25 hours a few days ago which contributed about 100 Amp hours of charge - 50% of total capacity.
On this passage thus far we've run Starlink for a total of 15 hours and have had a usable connection for perhaps 5 of those 15 hours. Starlink draws on average about 4.5 Amps (it uses most when trying to make a connection). That's 67.5 Amp hours to download a few gribs, and exchange emails and messages and have a couple of quick chats with home.
I had simply not 'budgeted' for that rate of consumption when I made the decision to buy it and the plain fact is we need more solar power or wind power to keep up with all the extra demand I've created. Remember we've already decommissioned our small fridge/freezer (sacrificing our ability to make ice in the process 😱) and since exhausting our supply of fresh meat, have increased the temperature setting for the main fridge! Quite what I can do
Back to Starlink. Although we hope that placing the dish in our home made gimbal will reduce the 4 hour connection time previously experienced, at this stage that is only a hope. It could take 4 hours once again or even longer!
So lets say we have it on for a total of 4.5 hours, that's 20 Amp hours of electricity - 10% of total battery capacity - consumed. If we manage to get our batteries back up to 56% of capacity by the end of charging this afternoon, after Starlink we'll be down to 36% of capacity. On average we use about 26% of capacity overnight (that is from when the solar panels stop providing a net charge to when they start doing so once again). That would reduce capacity tomorrow morning to a low point of about 10%. Which means we will most probably have to run the engine in the very near future.
We had our best daily run so far - 135 nautical miles. As at 1745 local time today we have 652 to run to our waypoint just north of Barbados. Given that, for now our ETA remains 28/12. That may change tomorrow once we download and digest a new grib.
[*Due to our power issues we mainly only use the water maker to produce drinking water and we are therefore running our main water tank down. The original intention had been to run it a few hours everyday to keep our main tank topped up too. We have plenty of water left for this passage but it does mean that at some point we'll need to fill our tank from a shore supply]
STOP PRESS - Next post will include exciting news re round 2 of the Mid Atlantic Bake Off!
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