Windlass battery size!

[JOHNPEET]

What’s the rule of thumb for sizing a dedicated windlass battery? I have a 24v Lofrans Kobra that draws 59amps at the rated working load. 60m of chain and the windlass will haul 25m/min at rated load according to the manual. What are the thoughts about how much battery capacity would be typical?

 

[Elessar]

What’s the rule of thumb for sizing a dedicated windlass battery? I have a 24v Lofrans Kobra that draws 59amps at the rated working load. 60m of chain and the windlass will haul 25m/min at rated load according to the manual. What are the thoughts about how much battery capacity would be typical?

Why not cable it back to the main batteries? Those cables can charge the bow thruster battery which operates for far less time than a windlass.

 

[JOHNPEET]

Why not cable it back to the main batteries? Those cables can charge the bow thruster battery which operates for far less time than a windlass.

The distribution system is already completed and set up for three battery banks - house, engine start and windlass. No bow thruster!

 

[Elessar]

The distribution system is already completed and set up for three battery banks - house, engine start and windlass. No bow thruster!

Bit late to say why no bow thruster!! I love your project but you may regret that…..

To answer your question try MDS battery. The owner is called Mike and he’s a boater - a Sealine.

Call and ask. He knows his stuff. He’ll sell you the battery too of course.

 

[Mudisox]

Surely your main engine will be running when you use the winch, which should help the load, assuming that this will charge as you use it. It does for me,

 

[JOHNPEET]

Surely your main engine will be running when you use the winch, which should help the load, assuming that this will charge as you use it. It does for me,

Yes, the engines will be running when the windlass is used. I just wondered how much capacity people typically install to buffer that load whilst the windlass is running or is it the case that in most instances, this battery would also feed the bow thruster?

 

[vas]

The distribution system is already completed and set up for three battery banks - house, engine start and windlass. No bow thruster!

are all three banks one next to the other, or you've routed a thinish cable to the bow to charge the windlass battery which will be up front?
If the former, I'd just add a short stub to the engine battery and see how it goes. TBH, haven't heard anyone using a dedicated windlass battery, ppl seem to do that for bowthrusters. I didn't, but got a massively thick cable (well two) and had a hard time routing them (with boat in full rebuilt mode though!) so can understand why ppl are reluctant to route from stern to bow.

V

 

[Tranona]

My last boat a Bavaria sail boat had a bow battery for the windlass and bow thruster. 12V 95Ah AGM. My current boat has the same but just for the windlass and I will use it for a bow thruster if I ever fit one. Most important, particularly for bow thrusters is cranking amps as like an engine start it needs high current draw for short periods. Advantage of bow batteries is the reduction in cable size. I only have 10mm sq from the charger compared with 70 required if drawing direct from a battery in the aft of the boat.

 

[JOHNPEET]

are all three banks one next to the other, or you've routed a thinish cable to the bow to charge the windlass battery which will be up front?
If the former, I'd just add a short stub to the engine battery and see how it goes. TBH, haven't heard anyone using a dedicated windlass battery, ppl seem to do that for bowthrusters. I didn't, but got a massively thick cable (well two) and had a hard time routing them (with boat in full rebuilt mode though!) so can understand why ppl are reluctant to route from stern to bow.

V

My windlass battery will be mounted around mid ships in the engine space. I have 50mm cables going forwards to the windlass contactor.
I was originally going to install the battery forwards, but then decided to arrange the switching on the battery switches so that I can feed the windlass from the house battery if required. Belt and braces!

 

[SC35]

Belt and Braces would be to install a Bow Thruster while you still can.