Bobc
Well-known member
Then he needs to put them somewhere more sensible.
Battery recommendations
- Thread starter StephenKennedy
- Start date
Refueler
Well-known member
You sure ? Not being smart .. but surely the Golf Cart has a lot more cells and voltage - so the watts required is manageable. An anchor winch usually is powered by a single battery / alternator - so voltage is only at the 13 ish volts ?? with voltage drop ... 11 maybe ? That means amps will ramp up.
Just thinking ..
PaulRainbow
Well-known member
But what if his boat is 60ft and the batteries are midships ?
PaulRainbow
Well-known member
Looks like typical golf carts are 36-48 volts, that's 6-8 batteries. Not quite the same as an anchor winch
Tranona
Well-known member
Yes, I seem to remember that when he did try to explain his beliefs his explanations were difficult to follow or just plain wrong.
Zing
Well-known member
Are you serious? You really don't know the facts after all the threads on this here. I don’t believe it, so I suspect you are trolling.
Due to their vastly superior peukert factor all lead, especially a part discharged lead battery is incomparibly less capable than even a much smaller lithium battery. You can’t compare like capacity for like and this makes them a good choice for a windlass or bow thruster. They cost more to buy, but given that fact and their hugely higher cycle life they are cheaper. It’s actually even better as it’s not just cycles they are superior at. They can be safely discharged far deeper with less loss of life capacity compared to lead. Put this together and the total lifetime charge/discharge amps per £ is even higher still. Even drop in lithiums with built in BMSs are cheaper when this is factored in. Home assembled, much cheaper still. Chargers cost the same and most decent lead chargers work fine, so they are not an obstacle. Then you have other technical advantages, the vastly superior charge rate, the even more superior total charge time. From start to a proper float on lead takes 24 hrs. Lithium it's just 3 hours or less. Then there is the vastly superior discharge rate. The superior charge efficiency. The superior weight. The vastly superior ability to not be damaged by prolonged partial discharge, The superior size. The superior safety. As they come with BMSs you can’t destroy them by under or over charging. Lead are destroyed often by total discharge. Superior self discharge rate. etc.
If you need precise numbers DYOR here:
www.google.com
So now you tell me in what significant way you think lead is superior to lithium. or was your question really naive curiosity?
Last edited:
PaulRainbow
Well-known member
@Zing Still no answer to #22
PaulRainbow
Well-known member
Lots of suggestions for the OP (wonder if he'll ever return, not been back since the day after he posed the question) but as no-one knows anything about his boat, how many batteries he has, how he can charge them etc, it really is next to impossible to offer anything with any confidence that it will be suitable.
That said, it seem remarkably unlikely that fitting a Lithium battery at the bow of a boat with all LA batteries is going to make any sort of sense. Post #46 lists various benefits of fitting Lithium, but how many are actually relevant to a battery for the windlass ? A LA battery can do everything required for a windlass battery. A 100ah Renogy battery costs £430, add to that a modest DC-DC charger and you're up to £550. You can buy a decent leisure battery for £87, plus a VSR and it's £130. Both of those examples exclude the wiring, because they'd be more or less the same.
But one thing that seems to have been overlooked in general is the fact that the OP already has an installation that includes the windlass battery. A 90ah leisure battery to replace the existing one is just £87, job done. You'd need to buy 6 of those to come up to the cost of the Lithium drop in (and that excludes the cost of the wiring). The leisure battery should last 6 years or more, that's 36 years of service for the cost of the lithium, by which time the Lithium will have been replaced at least once.
This is the OPs first boat, what's the chances of him keeping it long enough to have to replace the leisure battery even once ?
That said, it seem remarkably unlikely that fitting a Lithium battery at the bow of a boat with all LA batteries is going to make any sort of sense. Post #46 lists various benefits of fitting Lithium, but how many are actually relevant to a battery for the windlass ? A LA battery can do everything required for a windlass battery. A 100ah Renogy battery costs £430, add to that a modest DC-DC charger and you're up to £550. You can buy a decent leisure battery for £87, plus a VSR and it's £130. Both of those examples exclude the wiring, because they'd be more or less the same.
But one thing that seems to have been overlooked in general is the fact that the OP already has an installation that includes the windlass battery. A 90ah leisure battery to replace the existing one is just £87, job done. You'd need to buy 6 of those to come up to the cost of the Lithium drop in (and that excludes the cost of the wiring). The leisure battery should last 6 years or more, that's 36 years of service for the cost of the lithium, by which time the Lithium will have been replaced at least once.
This is the OPs first boat, what's the chances of him keeping it long enough to have to replace the leisure battery even once ?
geem
Well-known member
And it would be a complete waste of money for this application. Don't get me wrong, I love my lithium batteries but why use one for this application?
Tranona
Well-known member
While it is true that lithium has some properties that are different (and arguably superior) to LA that does not mean that it is an appropriate choice in all cases. Many small yachts simply cannot make use of the "superior" properties either because the equipment they are powering does not need it, there is a lack of charging resource to make use of the properties and most importantly the pattern of usage can never justify the cost of changing the system to use those properties.
It is too easy for some to be blinded by technology that is superior in some respects and to see it as a universal answer in all situations when in fact its application is limited to situations that can exploit those properties. The original question here is a typical example. It is a simple replacement of an existing LA battery in an application where a high current output LA battery is precisely what is needed, and the choice is really only around whether the owner is prepared to pay for the potential longer life of an AGM over an FLA. Lithium offers no advantages and changing will require changes to the charging systems on the boat.
Not sure you have actually done any serious analysis of the way that yachts are commonly used and the type of equipment they have fitted as you seem just to parrot "properties" some of which are questionable without any attempt to explain how these properties might be of value to users.
For many users with existing boats lead is far superior to lithium. It is a cost effective way of providing energy storage for their usage pattern and does not require any changes to existing charging systems. AGMs have a typical life of 10-15 years in a domestic bank when used for cruising in the weekend/holiday pattern common here in the UK. If the usage pattern changes or additional power consumers added there may be a strong case for changing the electrical system to use the different properties of lithium. Many people are doing this and writing up their experiences here. Fortunately most are realistic and recognise the challenges of doing it properly, and more importantly what they hope to achieve through change. A far cry from your simplistic view - which is not helped by continually trying to put down people who challenge you.
Sandy
Well-known member
Yes I am serious and thank you for taking the time to reply.
One of the great things about forums like these is the ability for people to share there knowledge and expertise. Your posts came across as somebody who thought that everybody in the world should be using Lithium batteries, especially after your comment about their use in motor vehicles. I was not trolling, I have a thirst for knowledge and needed you to explain your position.
Given the number of times a year/month/day that an anchor is dropped/lifted then the battery mass and charging profiles are hardly relevant unless you are a liveaboard moving from anchorage to anchorage on a daily basis. Personally, I have yet to meet a boat that does that sort of thing. My own style of sailing is often multi days underway followed my multi days at anchor or mooring ball/marina. Which is very much the style of sailing that most I meet do.
The initial capital cost of lithium is well understood. I have yet to be convinced that the total cost of ownership is less than older technologies. This is mainly because the number of boats who are using the lithium is very small and they have not been using them for long enough to build a sizable data source.
For the majority of boats the cycle life of any type of battery is very, very low. I'd evidence that by the amount of waterline 'beards' seen on vessels in marinas across the world. I have seen boats not move from their pontoon in years.
Empirical evidence shows that most people wreck batteries because of not knowing how to charge them properly, in other words abuse. I can give one example where a sailor though that he did not need to top up his batteries with water. £750.00 worth of battery written off in under a year.
To date this is just use under test conditions. I would like to see some real life data from several boats that have worked their batteries hard for several years.
How many people either have the skills or the inclination to home build? My first degree is mainly electronics based and I'd even think twice as I actually want to go sailing rather than mess about with wiggly amps again.
How often do people replace their chargers? In 2022 I replaced the original charger, fitted in 1986, with a modern Victron IP 22, currently £204 on Amazon, so unless you have a modern charger there is quite a capital investment just to get a shore power charger. There might also be a need for solar MPPT and alternator upgrades. I can see that cash register filling.
Fine if you decide that is is time to upgrade all of the boats DC power generation and storage, but the OP was looking at one battery that might be use once a week for six weeks in a year.
Being an old, hairy, Scottish engineer I get extremely suspicious of words like vastly and superior as they come straight out of the marketing handbook. The charging rates, depth of discharge, discharge rates and mass are different. Nothing more, nothing less. A newer and different technology will be along in the next few years time and will be shouting from the rooftops that is far more 'superior'. Sodium-ion batteries anybody, safe nuclear fusion?
Lithium might have its place, I am sure you can tell I am not convinced, but why does my insurance company requires me to declare to them that I have lithium onboard? For the majority of boats who spend 99% of their time tied to a pontoon or on a mooring that place is not in them. For a liveaboard who has limited power generation onboard and is power hungry then yes they have a place. I am afraid I like my beer warm, not 0.001° above its freezing point, nor do I need a hair dryer onboard hence my power usage is low. I also use paper charts, how power hungry is OpenCPN?
Lead is not superior, it is different. Both technologies need to be understood by their users. From the evidence of this and many other threads in this and other forums users have little understanding of the use of batteries of any sort.
Zing
Well-known member
What are you - an ex Stasi agent?
PaulRainbow
Well-known member
I suppose if you admit how much it would cost it would highlight how ridiculous your claims are.
Zing
Well-known member
What are you getting me to admit? You’ll get no signed confession from me.
No, you are wrong and you are comparing apples and pears.
How about this one:
LiFePO4 12V 50Ah Lithium Iron Phosphate Battery | ECO-WORTHY
or this:
12V 50Ah Lithium Iron Phosphate Battery
So about £150. Smaller capacity of course, but due to peukert, no volt drop and a much wider useable charge range will do a similar job to your useless lump of £100 lead, with all its other disadvantages and a fraction of lithium’s life. Lead is ultimately more expensive and poorer quality.
Alternatively compare lithium with a decent lead battery like an Odyssey:
Odyssey® ODP-AGM31 (31-925S) 12v 100Ah Performance Battery - Free U.K. Mainland Delivery
So £300 and twice the price and it will die three times quicker than the cheaper lithiums.
It‘s not often that a cheaper thing is also better like here, yet so many like you are stuck in the mud on the question. It is you that is ridiculous.
Refueler
Well-known member
Lithium vs LA ...
I read some posts above .. Zing's come to mind !!
I interpret similar when it comes to which car to buy ...
You can buy a Lada to do the job ... or you can buy a Mercedes - they will both do the job - but costs are way out of comparison.
One person will swear by the Lada and know that 5yrs down the road its junk. But he can afford to replace it. The other person swears by the Merc .. he'll likely get 10yrs out of it before he sells on at huge depreciation ... buys another ...
The costs difference is still huge even though the Merc went 2 or 3x the life span.
I read some posts above .. Zing's come to mind !!
I interpret similar when it comes to which car to buy ...
You can buy a Lada to do the job ... or you can buy a Mercedes - they will both do the job - but costs are way out of comparison.
One person will swear by the Lada and know that 5yrs down the road its junk. But he can afford to replace it. The other person swears by the Merc .. he'll likely get 10yrs out of it before he sells on at huge depreciation ... buys another ...
The costs difference is still huge even though the Merc went 2 or 3x the life span.
PaulRainbow
Well-known member
Now you are just distorting things to fit your argument, as usual.
According to the Renogy link you posted you would need two of those £150 batteries for a simple 1000w inverter, that's about the same power requirements as a typical windlass, plus the DC-DC charger, plus cabling = about £500
Then, you link to the most expensive LA battery you could find, which is totally not needed by the OP.
So, to support your argument you compare a battery that's only half as big as needed to one that's three times as expensive as needed. Not really a compelling argument, is it ?
All the OP needs is to replace his existing LA with a similar one, costing just £87.
geem
Well-known member
You think it's fair to compare the cheapest, crappiest lithium battery with one of the most expensive lead batteries on the market? The guy doesn't need a ,lithium battery. Get over it!
Tranona
Well-known member
As usual this is just nonsense as others have pointed out. It is you that is comparing apples with pears - and it is not price that is the issue. Anyway why do you think that these two products are being offered at such massive price reductions? Surely if they were "superior" there would be no need to discount them. Even at this "bargain" price they are nearly double the price of the battery the OP needs, as well as being unsuitable for his application.
The battery is only part of the energy system of a boat and it is pointless considering just the battery in isolation. Beginning to wonder if you have any experience or knowledge of what is actually involved in energy systems for boats.
Graham376
Well-known member
No need for expensive technology batteries for engine or dedicated windlass use, bog standard sealed or open la car battery will be fine, as I've had for years. My domestic bank is 4 x Trojan T105 which use the same charging regime.
GHA
Well-known member
though your windlass will love you deeply and truly for the nice high voltage liFePo4 can supply even when nearly empty. First use for me on new LiFePo4 it was "Oh now you're awfully keen today"
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