Anchor Windlass Battery Question

[JOHNPEET]

There doesn’t appear to be a lot going on in terms of resilience in the above suggestions!
A lithium house battery that is suggested as being unsuitable for engine starting and an ”engine starter” battery that a number of other loads could or should also be connected to it - some of which could easily be inadvertently left on with the potential of flattening the battery leaving the owner vulnerable at the next engine start attempt!

Perhaps a more resilient approach in this instance would be to install a second “engine starter” with a 1- Both - 2 - Off switch, which would allow the isolation of one of the engine starters whilst at anchor. This would always ensure a reliable engine starter to get home.

 

[PaulRainbow]

There doesn’t appear to be a lot going on in terms of resilience in the above suggestions!
A lithium house battery that is suggested as being unsuitable for engine starting and an ”engine starter” battery that a number of other loads could or should also be connected to it - some of which could easily be inadvertently left on with the potential of flattening the battery leaving the owner vulnerable at the next engine start attempt!

Perhaps a more resilient approach in this instance would be to install a second “engine starter” with a 1- Both - 2 - Off switch, which would allow the isolation of one of the engine starters whilst at anchor. This would always ensure a reliable engine starter to get home.

I would stick to the "engine battery is for engine starting John", personally. I can't see any good reason to use it for anything else, with the exception of the windlass, using that should only be done with the engine running. I always fit an emergency parallel switch between the load terminals of the engine and domestic isolators. That would prove handy in the event of Lithium shutdown, isolate the domestic bank, turn on the emergency switch and you have essential services back again, obviously keeping the engine running whilst sorting out the issue.

 

[Aja]

Thanks for all the input.

So, if I'm just going to run a 35mm cable to the bow, which wopuld be better to run it from, the 200ah Lithium domestic or 86ah lead acid engine battery?

I ran 50mm called from my LA starter battery to my Lofrans Kobra 1000W windlass.

The difference in price and weight of the cable was small between 35mmand 50mm and I suspect there is little drop in volts. Some may say that this is overkill, but it works.

I don’t often raise or lower the anchor without the engine running - this provides the power for the windlass and recharges the starter battery - although I sometimes sail off the anchor just to keep my hand in.

 

[JOHNPEET]

I would stick to the "engine battery is for engine starting John", personally. I can't see any good reason to use it for anything else, with the exception of the windlass, using that should only be done with the engine running. I always fit an emergency parallel switch between the load terminals of the engine and domestic isolators. That would prove handy in the event of Lithium shutdown, isolate the domestic bank, turn on the emergency switch and you have essential services back again, obviously keeping the engine running whilst sorting out the issue.

I was generalising based on the collective comments made by various posters.

as you will see from my initial response - I am a firm believer in dedicated batteries and I can assure you that my engine starter batteries do exactly that and nothing else.

Yes, it is usual to have the engines running when hauling the anchor with the windlass, but typically this will be with the engines running at idle and so the alternators won’t be generating a great deal of power at that point, hence the need for a battery to buffer the load of the windlass

 

[QBhoy]

I'm not flustered and the needless sillyness is you, starter batteries should be starter batteries, that's simple enough.

Ok

 

[PaulRainbow]

I was generalising based on the collective comments made by various posters.

as you will see from my initial response - I am a firm believer in dedicated batteries and I can assure you that my engine starter batteries do exactly that and nothing else.

Yes, it is usual to have the engines running when hauling the anchor with the windlass, but typically this will be with the engines running at idle and so the alternators won’t be generating a great deal of power at that point, hence the need for a battery to buffer the load of the windlass

I didn't think for a minute yours would not be as they are John, i've seen your build thread over at the mobo forum

 

[Sea Change]

I shied away from running long cables because by the time you've done a realistic measurement of the actual length (always much longer than you think by the time you've gone around various obstructions) the voltage drop was starting to look pretty bad unless I went for seriously heavy cable, which is not fun to work with, or cheap.

So I fitted a 110Ah lead acid as close to the windlass as possible, and ran 50mm² from there.

To charge it, I was planning on a small 18A DC-DC charger, but as a temporary measure I just hooked up my 30A Victron battery charger, running off my inverter. It tells me that on average it takes 2.5Ah to fully recharge the battery after each use of the windlass. It's such a tiny amount that I can't really bring myself to throw nearly £200 at a DC-DC charger that is doing so little work. So now I just charge through the inverter. It's not exactly elegant, or especially efficient, but I can buy a lot of rum with the money I've saved...

 

[JOHNPEET]

I shied away from running long cables because by the time you've done a realistic measurement of the actual length (always much longer than you think by the time you've gone around various obstructions) the voltage drop was starting to look pretty bad unless I went for seriously heavy cable, which is not fun to work with, or cheap.

So I fitted a 110Ah lead acid as close to the windlass as possible, and ran 50mm² from there.

To charge it, I was planning on a small 18A DC-DC charger, but as a temporary measure I just hooked up my 30A Victron battery charger, running off my inverter. It tells me that on average it takes 2.5Ah to fully recharge the battery after each use of the windlass. It's such a tiny amount that I can't really bring myself to throw nearly £200 at a DC-DC charger that is doing so little work. So now I just charge through the inverter. It's not exactly elegant, or especially efficient, but I can buy a lot of rum with the money I've saved...

If you’re using a liquid type lead acid battery, just need to bear in mind the requirements for adequate ventilation. This can be challenging when the battery is located up forward.

I’ve seen what can happen when a battery explosion occurs!

 

[Frankklose]

What's about using an even smaller battery? I just bought a Lofrans Kobra 1000W 12V, in order to replace the Lofrans Royal a manual windlass.
I dont want to run heavy cables, plus my start battery has only 70A and the house battery is a LIFEPO4 280Ah. In addition I have a 2kW inverter.
Just swapped out the Renogy 40 A B2B and replaced it with the new Victron OrionX. So I have the old Renogy which I could use or I cold use a normal 240V charger.
I dont think the JBD BMS of the LIFEPO4 will supply enough current, the starter battery is too small with 70A. Therefore I have to have a dedicated battery in the bow. I have even been thinking of using a 100A Lithium supplying the windlass direct and using the BMS only for charging. Lithium has very little discharge current and the windlass is not often used.
How would you configure the supply to the windlass?

 

[Alan S]

KISS. How about a SLA csr battery with its own small solar panel and controller? No cables at all from aft to forward unless you want control from the helm in which case you only need a thin 3 core cable.
The cheapest and most reliable system?

 

[Tranona]

You don't need a lithium to power the windlass. A good LA or AGM of around 100Ah is fine. I have a 110Ah Numax which does both the Kobra windlass and a bow thruster. As for charging, originally the previous owner just used solar for the windlass, but after adding the thruster it is now charged with a 30A B2B from the start battery

 

[PaulRainbow]

I'd basically go with some of the previous replies. Definitely not Lithium. AGM is a good solution for a windlass and charge it with the Renogy B2B.

Out of interest, why replace the Renogy ?

 

[Frankklose]

Paul
The Renogy has very low efficiency about 80%. Reset after error only works if input and output is removed (added a circurit breaker to do it) didnt work in the engine room max temp is 50 degrees most likely measured on heatsink. At 46 degrees room temperature it turns off. Had to move it into the locker.
The 20 A setting was not bad, but with 40A the error light came on intermittend and I could not figure out for which reason. Circuit breaker off/on and it worked again for the rest of the day

The OrionXs is installed back in the engine room and makes no problems....had the Renogy installed for more than 3 years always trouble... hate that thing. The OrionX is trouble free only the set up can be tricky. Battery type must be selected first otherwise it will only charge at max 20 A. Therefore Factory Reset, than Battery Type and than charge current and it works That's the only shortcoming so far. The Bluetouth setup is also very good, if done in the proper order. Software update via Bluetooth automatic....very clever with the smartphone.