What size and type batteries do I need for a crossing.

[sebathon]

Hi,

Just in the process of upgrading electrics onboard a 40’ cruiser for a planned Atlantic crossing this year and not really sure on the total capacity or type needed for this.Currently have 280Ah ( 2x 140) lead acid cells and it’s never really capable of running the AP for anything longer then an hour or so.

My usage is mainly autopilot between 2 and 8 amps depending on weather, fridge usually 7amps and some basic instruments and lights and device charging.

Have installed silentwind 400w and 440w solar which has helped a little but I’m concerned to total Ah storage is not sufficient.

If anyone’s does a similar trip and knows what’s works well or doesn’t, advice would be much appreciated.