Best type of battery for anchor windlass?

[Paddy Layback]

Hi ther, I wonder if there is a best type of battery for a 12v Lofrans Falkon (like a Tigre but a bit bigger)

I would ideally like ones which can deliver most of their stored ampere-hours until they are nearly flat, thus getting the best value from the weight being carried. Some sort of deep cycle jobs?

It/they will be under the fore berths, weight is not an issue at all (13 ton boat) and not really pushed for space.

In old fashioned truck battery terms, there is easily room for a pair of 120 Ampere-hour size. (Obviously truck starter batteries would not be ideal.)

Ideally, charging by an ordinary Volvo marine alternator, backed up with solar, rather than any fancy palava.

Thanks PL

 

[VicS]

Hi ther, I wonder if there is a best type of battery for a 12v Lofrans Falkon (like a Tigre but a bit bigger)

I would ideally like ones which can deliver most of their stored ampere-hours until they are nearly flat, thus getting the best value from the weight being carried. Some sort of deep cycle jobs?

It/they will be under the fore berths, weight is not an issue at all (13 ton boat) and not really pushed for space.

In old fashioned truck battery terms, there is easily room for a pair of 120 Ampere-hour size. (Obviously truck starter batteries would not be ideal.)

Ideally, charging by an ordinary Volvo marine alternator, backed up with solar, rather than any fancy palava.

Thanks PL

Sounds like a case for a Red Flash deep cycle battery. http://www.dmstech.co.uk/red-flash/red-flash-deep-cycle/

Otherwise a leisure battery with a good CCA rating

But don't forget any battery that is left even partially discharged will suffer.

 

[dom]

Agree with Vic and wld def think about a non-gassing sealed batt so close to one's bed! -- agm/sealed-lead are vented but way better than the old unsealed lead ones. Then there is the prob that the bow of a boat is a pretty violent environment: a shock induced plate collapse is a PITA and a split casing will create a right old mess -- it can't do the anchor chain much good if it ends up there!

For this reason i think many of the bowthruster pros recommend vibration/shock-resistant units like Optima yellow, which they also believe possesses the appropriate power curves. Ellesar (if he still posts here) or Plevier could prob provide a more definitive answer.

 

[Bru]

think about a non-gassing sealed batt .

There's no such thing in reality

Sealed lead acid batteries incorporate a condenser in the vent which recirculates the electrolyte but it can only cope up to a point and if the battery is heavily discharged and then subjected to a heavy recharge, some gassing can, indeed almost certainly will, still occur (repeated heavy cycling will shorten the life of sealed batteries for obvious reasons)

 

[dom]

There's no such thing in reality

Sealed lead acid batteries incorporate a condenser in the vent which recirculates the electrolyte but it can only cope up to a point and if the battery is heavily discharged and then subjected to a heavy recharge, some gassing can, indeed almost certainly will, still occur (repeated heavy cycling will shorten the life of sealed batteries for obvious reasons)

Agreed, 'sealed' but with a condenser vent is certainly a half way house, albeit a necessary one to release excess pressure. Re your point about repeated heavy cycling: I banged in 400Ahr of cheap and cheerful Chinese 'sealed' units in summer 2014. More Varta or Trotters & Co, only time will tell. Might be interesting to open them up for a look when they finally give up the ghost.

 

[GHA]

Ideally, charging by an ordinary Volvo marine alternator, backed up with solar, rather than any fancy palava.

Thanks PL

If you have a connection to the alternator and presumably the house bank then you'll need hefty cables anyway to allow for the possible high current going to the battery in the forepeak so is it worth the bother of fitting a battery in there over just going for big cables?

 

[[70521]]

Best type of battery for anchor windlass?

Something that you can use to start the engine should everything else be flat.

 

[Paddy Layback]

If you have a connection to the alternator and presumably the house bank then you'll need hefty cables anyway to allow for the possible high current going to the battery in the forepeak so is it worth the bother of fitting a battery in there over just going for big cables?

Thanks for all the answers above, there are surely some fancy batteries available these days!

To GHA: That's a good point you make there, I was mulling over using fat cables anyway, even with the batteries forward. (There isn't room for them aft really).

Using cables capable of carrying starter motor size currents the length of the boat would enable me to start the propulsion engine (Volvo 36) with the windlass batteries, which might come in handy one day..as Sandy above points out..

One complication, of course, is charging different types of battery off the same alternator, some hard thinking/research to be done!

 

[[70521]]

Using cables capable of carrying starter motor size currents the length of the boat would enable me to start the propulsion engine (Volvo 36) with the windlass batteries, which might come in handy one day..as Sandy above points out..

I've got mine set up so I can move the windlass battery from one end of the boat to the other should I need to use the battery to start the engine. I would not trust a 5 meter cable run to start the engine (Volvo 2002).

 

[pvb]

Thanks for all the answers above, there are surely some fancy batteries available these days!

To GHA: That's a good point you make there, I was mulling over using fat cables anyway, even with the batteries forward. (There isn't room for them aft really).

Using cables capable of carrying starter motor size currents the length of the boat would enable me to start the propulsion engine (Volvo 36) with the windlass batteries, which might come in handy one day..as Sandy above points out..

One complication, of course, is charging different types of battery off the same alternator, some hard thinking/research to be done!

The Falkon windlass draws about 135A, similar to many starter motors, so almost any decent battery would theoretically do the job. A "sealed" AGM would be ideal. However, your idea of running the battery down is a bad one, this will lead to premature battery failure, not to mention the risk of the battery not being able to cope if you have some unplanned extended windlass operation. Additionally, because the windlass draws a high current, the effective capacity of the battery is reduced significantly. Typically, a 100Ah battery subjected to a 135A load will have an effective capacity of only around 35Ah, and if fully-charged would be 50% discharged in less than 10 minutes' use. So you would probably need to install 2 x 100Ah to be sure of a reasonable reserve of power.

Unless you install some advanced "echo charge" system, you will need hefty cables to ensure that they can cope with the high current during charging and windlass operation. And you will need to fuse the cable next to the windlass, as well as next to the house batteries. By the time you've done all this, and paid for 2 new batteries, it's probably cheaper just to install hefty cable and run the windlass direct from your existing batteries.

 

[GrahamM376]

it's probably cheaper just to install hefty cable and run the windlass direct from your existing batteries.

That's what I did. Windlass is connected to battery selector/isolator switch (via MCB) so I can run it off engine or domestic batteries. Usually select the engine battery as it's charging most times I haul anchor.

 

[Plevier]

There's no such thing in reality

Sealed lead acid batteries incorporate a condenser in the vent

Totally incorrect. In AGM batteries the recombination depends on migration of nascent gas through the unsaturated absorbent separator (or through micro cracking in the gel in gel cells, much less effective) to recombine at the other plate.
If you overcharge too much for this mechanism to cope and get free gas reaching the vent (actually a pressure relief valve) you are in trouble.

Catalytic recombination vents were tried on flooded batteries but not with much success, they tend to get poisoned quickly and become ineffective.

 

[Mister E]

If you were to use a voltage sensitive split charge relay to charge the Windlass battery you would not need heavy duty cables.
But it would only charge at about 20amps max and when the engine is charging. So if you were to flatten the windlass battery you would have to wait a while for it to charge up again.

 

[geem]

We have the same windlass. We have big cables from domestic battery bank to windlass. 900 amp hr domestic bank. What happens if you flatten your dedicated windlass battery? You will be pulling some serious current and if you need to reanchor a couple of times you could be faced with a flat battery. I would consider the dedicated windlass battery as inferior set up to large cables fed from the main battery bank. Whilst lifting your anchor you will likley have the engine on. You will be recharging your domestic bank from the alternator at the same time. Why not keep it simple and go with large cables?

 

[pvb]

If you were to use a voltage sensitive split charge relay to charge the Windlass battery you would not need heavy duty cables.
But it would only charge at about 20amps max and when the engine is charging. So if you were to flatten the windlass battery you would have to wait a while for it to charge up again.

That's incorrect; if the windlass battery was heavily discharged, the charge current could be much higher than 20A, subject to the alternator capacity. Additionally, if the windlass were to be operated at the same time as the engine was running, the windlass would draw current both from the windlass battery and the main batteries, via the VSR - again this could be much more than 20A.

 

[Bru]

Totally incorrect. In AGM batteries the recombination depends on migration of nascent gas through the unsaturated absorbent separator (or through micro cracking in the gel in gel cells, much less effective) to recombine at the other plate.
If you overcharge too much for this mechanism to cope and get free gas reaching the vent (actually a pressure relief valve) you are in trouble.

Catalytic recombination vents were tried on flooded batteries but not with much success, they tend to get poisoned quickly and become ineffective.

It would indeed have been totally incorrect if I had been talking about AGM batteries. I wasn't! I was talking about bog standard sealed lead acid batteries

 

[Plevier]

OK Bru, I'm glad you appreciate the difference, but you have fallen into a terminology trap then.
You're talking about sealed maintenance free - but even those don't have a "condenser".
Sealed lead acid means AGM, or the preferred term now is VRLA - valve regulated lead acid.
As long as they are not overcharged, VRLAs do not gas at all, in your post you said there was no such thing as a non-gassing sealed battery.
However a sealed maintenance free (MF in new standard designation) is not non-gassing I agree.

 

[Daedelus]

I understood that with the very high current draw for a comparatively short time that a starter type battery was better than the deep cycle. It was recommended fit a starter battery near the windlass so that the hefty power cables would be shorter.

Somewhere or other I read about a device which is a form of voltage modifier for charging the remote windlass battery. Because there would be a voltage drop in small cross section cables this device which was supplied by small cross section cables increased the voltage to charge the remote battery. If you are really interested ask one of the marine instrument/electric outfits as a quick google didn't find what I was looking for.

 

[Mister E]

That's incorrect; if the windlass battery was heavily discharged, the charge current could be much higher than 20A, subject to the alternator capacity. Additionally, if the windlass were to be operated at the same time as the engine was running, the windlass would draw current both from the windlass battery and the main batteries, via the VSR - again this could be much more than 20A.

A caravan type ready made split voltage sensitive charge relay would limit the current as they are designed to do that to avoid the need for battery rated heavy duty cables.
If you were to make your own then that would be a different thing altogether.

Maybe I should have stated a purchased spit charge relay intended for fridge/battery charging uses.

 

[pvb]

Somewhere or other I read about a device which is a form of voltage modifier for charging the remote windlass battery. Because there would be a voltage drop in small cross section cables this device which was supplied by small cross section cables increased the voltage to charge the remote battery. If you are really interested ask one of the marine instrument/electric outfits as a quick google didn't find what I was looking for.

If you want to have small cables feeding the windlass battery, the solution is an "echo charge" system as I mentioned in post 10. This will sense when the alternator is charging and, when it is, it will charge the windlass battery - but at a low maximum current, in order to allow the use of small cables. Xantrex make a unit which has a max 15A output. Adverc sell a range of DC-DC chargers with various outputs, starting at 12A.