Power Consumption of a Autohelm ST 4000

[Adonnante]

I recently measured the electrical consumption of all the bit and pieces on my boat with a view to increasing my number of solar panels. The one piece of equipment I couldn't measure was the ST 4000 Autohelm, this is a pity as it is vital to much of my sailing. My best guess for a 24hr period would be in the region of about 25/30 Amp/hrs, has anybody measured this and does my assumption look realistic?

Peter.

 

[Bav34]

Never measured it but the Owners Handbook says:

Standby: 0.72W

Auto: 10W at 25% duty cycle (depending on boat trim, helm load and sailing conditions)

 

[MagicIsland]

Depends on sea conditions, trim setting and tiller drive unit, but on a recent long trip from Falmouth to Wells -next -the-sea in a mix of slight to mod sea I worked out ours was drawing about 4 amp per hour when doing all of the helming, mostly motor sailing (Dam that east wind !) . I think it would vary trip to trip .

 

[earlybird]

I recently measured the electrical consumption of all the bit and pieces on my boat with a view to increasing my number of solar panels. The one piece of equipment I couldn't measure was the ST 4000 Autohelm, this is a pity as it is vital to much of my sailing. My best guess for a 24hr period would be in the region of about 25/30 Amp/hrs, has anybody measured this and does my assumption look realistic?

Peter.

Depends a lot on boat and conditions I'd expect, but a good while back, PBO ran a series of tests with a datalogger on various autopilots.
A 4000+ Tillerpilot, on a 33ft. long-keeler in "lively" conditions averaged ~1.5 amps and peaked at about 5 amps, keeping a good course.
You guess probably isn't too far out.

 

[Storyline]

I had an ammeter in our previous boat and our 4000+ used to average between 1-2 amps. I had only one domestic battery and it was our biggest drain. I found that by installing a rudder reference unit and tweaking the settings I reduced the consumption by around half an amp.

 

[Adonnante]

Thanks for your help, it looks like it might be advisable to up my estimate to around 40 Amp/hrs. In easy sea conditions I might even be able to switch on the cool box to chill the beer, failing that its back to the net bag and 10 minutes on the bottom once anchored.

Peter.