Powering a windlass - Thoughts

[evm1024]

Today I dumped all my chain on the sea bed and set up a meter (Victron BMV 602S) to measure the AH used.

The bow roller to seabed distance was 30' And the chain is 5/16 G70. There was 300' feet of chain and an 85 pound Mantus. The chain is about a pound a foot so for most of the recovery the windlass was pulling 30 pounds plus an unknown multiplier for drag. In the end it was pulling 115# times the multiplier.

The windlass is an Ideal BWH and runs at about 10" per second. It took 6 minutes to pull the full 300' back in. The windlass was warm at the end of the 6 minutes. Almost hot but not really uncomfortable to touch. I'm guessing that there is a Bit of a thermal mass overcome and do not have the ability to measure internally temp. Plus, it is loafing when pulling 30 pounds of chain.

In total the 300' pull consumed was 5.0 AH which works out to an average current draw of 50 amps.

This test represents the lower limit of the AH used. Obviously if you use the windlass to pull the boat forward or to break the anchor out of the seabed the current draw (and thus the AH used) will be greater.

Nothing exciting but now we know (at least for my boat).

[evm1024]

Just thought to follow up on this thread.

We are back after 3 years of cruising (with breaks back to the homestead).

I built a 4 cell EVE bank for the windlass and put it up in the forepeak. It was monitored by an older victron battery monitor and charged with an older 10A west marine battery charger. The charger was powered by 120 volts from the inverter and only when needed.

Over the course of cruising we monitored the AH consumed on the Victron and ended up charging the bank every 5 months or so. Sometimes more often when Lead Acid withdrawal struck.

For me this worked out very well. Battery to windless was 2/0 with fuse and shunt. 120 volt was from an existing 14 AWG outlet.

The windless was peppy no matter the SOC of the bank, don't think we ever got below 40% SOC.

And I did have piece of mind that I could either use the windless bank as a spare house or start bank in a pinch.

Best

[boatpoker]

Two group 31 wet cells at the bow, charged as the 3rd bank on my 3 bank charger run a 24V bow thruster and a 24V windlass ... series parallel switch and relay allows this 12V system to put out 24V.

[SailingHarmonie]

So much fussing about this issue. Sometimes simple is the best.

Lofrans 1500W windlass. 24 Volt house system. Cables run from 11.5kW-hr battery bank set roughly mid-ships on a 53 foot boat. Power usage is insignificant given the capacity of the house bank. Cost of the cables is not insignificant, but still less than another set of batteries, and associated charging and monitoring system, and additional maintenance and fussing.

Works. All the time. And has for 26 years and two circumnavigations.