Battery recommendations

[GHA]

I saidd it does not care where the power comes from - just what it is. That is why you us a battery with a high CCA for a windlass - as suggested for the OP. No one has suggested using Trojans for this job so not a valid comparison.

You need to back that up with data. High CCA doesn't mean "voltage doesn't drop much under load", Trojans are lead acid. AGMs are lead acid. If you want little voltage sag you need to look elsewhere than lead acid. Like LiFePo4.

You didn't look but if you did there's not much comes up immediately. From google scholar >

COMPARATIVE ANALYSIS
OF AUTOMOTIVE STARTING BATTERIES
IN THE ASPECT OF DIAGNOSTICS
RESEARCH
ANALIZA PORÓWNAWCZA SAMOCHODOWYCH
AKUMULATORÓW ROZRUCHOWYCH
W ASPEKCIE BADAŃ DIAGNOSTYCZNYCH

Apart from the used battery very little difference in voltage sag up to about 1C.




Time to shuffle those feet some more because you're wrong again....

 

[GHA]

Think @GHA bought his from Spain?

Mine came from China. $591 delivered to the boat in Portugal, 4 x CATL-LF302Ah-3.2V.
450UKP But just the cells, fuse cost as much as one of the cells. Rest of the bms was mostly stuff onboard already, voltage sensors etc. Though splashed out on no yet fitted latching relays, over a year & cells still closely matched. Balanced once when fitted.

But there's not really much to be gained looking a cost really, so many variables on different boats.
Another unusual cloudy day here but won't bother running the genny, only just under 30% soc so that will be fine til the morning. Lead acid I would have been burning loads of juice running the genny or even worse the main engine for hours very week trying to get lead acid back to really 100%. Hours of noise & fuel to get that last few Ah in.
Or watch them die.
And no one knows how long LiFePo4 will last with light use on a boat.

 

[Refueler]

Its quite normal for lifepo4 cells to have the same charge/ discharge rate. In my case, my two lithium batteries can handle 385A at 24v charge or discharge. The 2 parallel BMS can handle 400A at 24v, in theory. We are limited by the 3000w inverter, which for most people is the limiting factor. For us that means about 125A but for most people on a 12v system, it is half that

Appreciate your post - but it really means nothing to anyone else because without the capacity of each battery - there is no guide for others ... as you know the C rate x the capacity is the max amps you can discharge / charge at (C rate stated for each of course).

Same Charge . Discharge rate may be with batterys you have / looked at - but it is not across the board ... many Lithium based of all formats have different C rates for charge .... discharge.

 

[Refueler]

Mine came from China. $591 delivered to the boat in Portugal, 4 x CATL-LF302Ah-3.2V.
450UKP But just the cells, fuse cost as much as one of the cells. Rest of the bms was mostly stuff onboard already, voltage sensors etc. Though splashed out on no yet fitted latching relays, over a year & cells still closely matched. Balanced once when fitted.

But there's not really much to be gained looking a cost really, so many variables on different boats.
Another unusual cloudy day here but won't bother running the genny, only just under 30% soc so that will be fine til the morning. Lead acid I would have been burning loads of juice running the genny or even worse the main engine for hours very week trying to get lead acid back to really 100%. Hours of noise & fuel to get that last few Ah in.
Or watch them die.
And no one knows how long LiFePo4 will last with light use on a boat.

When did you receive them ? And by what shipping method ?

Interested to know ... shipping of batterys has been restricted for some time now.

 

[geem]

Appreciate your post - but it really means nothing to anyone else because without the capacity of each battery - there is no guide for others ... as you know the C rate x the capacity is the max amps you can discharge / charge at (C rate stated for each of course).

Same Charge . Discharge rate may be with batterys you have / looked at - but it is not across the board ... many Lithium based of all formats have different C rates for charge .... discharge.

I was looking at it from a cell perspective. When you buy a drop in battery, often the BMS is rated lower than the cell capacity. So you might see a 300Ah battery with a 200A BMS. If you fit 3 of such a battery in parallel, you don't have the restriction of the BMS anymore. You get 600 A continues maximum charge or discharge. Winston cells, the RR of lithium, can do 3C but very few cells from other manufacturers can do this. EVE, CATL both do 1C charge and discharge. It pretty normal.

 

[MontyMariner]

With all this talk about high drain batteries and going back to the OP's Q, I thought I would look at my old Seawolf windlass to see what the current drain is.
Typical, the Installation Book doesn't give any indication of current drawn, but it does say use 2.5 mm cable and the net suggests:-
2.5mm cable should be protected by a breaker no larger than 20 amps in a radial circuit.
On that assumption my windlass drawers less than that, so no need to tack on a high drain battery for the windlass
I don't know how much current other windlasses draw, but they can't be a lot different.

 

[PaulRainbow]

With all this talk about high drain batteries and going back to the OP's Q, I thought I would look at my old Seawolf windlass to see what the current drain is.
Typical, the Installation Book doesn't give any indication of current drawn, but it does say use 2.5 mm cable and the net suggests:-
2.5mm cable should be protected by a breaker no larger than 20 amps in a radial circuit.
On that assumption my windlass drawers less than that, so no need to tack on a high drain battery for the windlass
I don't know how much current other windlasses draw, but they can't be a lot different.

Those figures are very wrong, not a chance that 2.5mm cable would run the windlass. Might say use 2.5mm for the switches, but the motor will need much, much more.

EDIT Page 4 of the manual on your website states 16mm, 25mm or 35mm, depending on cable length.

 

[PaulRainbow]

The windlass very much cares what the voltage is. Why would you assume a flat battery? Sounds like you don't really know much about internal resistance or Ohms law.

Pull a load of amps from a couple of trojans the voltage will be way down. Just tried it. At rest with just house loads, (smartgauge says 93%) - 12.6V, run the windlass - 11.7V. Measured with a Fluke onto terminals.

LiFePo4 @ 25%SOC doing the same > 12.6V. For a motor that's huge. Which anyone who runs a windlass & swapped to LiFePo4 knows already just by the sound.

Do you think the windlass manufacturers are not aware of voltage drop, especially since they have been powered by lead acid batteries since they were invented ?

Same with bow thrusters, the manufacturers know about voltage drop.

Windlass and bow thruster batteries are rated as low at 10.5v for 12v systems. If they needed the full 12.x volts, there wouldn't be a properly working windlass or bow thruster in existence. Come to that, you wouldn't be able to start your engine, for the same reasons.

 

[MontyMariner]

Page 4 of the manual on your website states 16mm, 25mm or 35mm, depending on cable length.

I must get some new specs, I looked at the bit at the top of p6 so could be up towards 140 amps

 

[Tranona]

Time to shuffle those feet some more because you're wrong again....

I admit to being a simple soul, but I have had boats with windlasses and bow thrusters for 25 years using either Leisure batteries or stop/start AGMs and have NEVER experienced problems. No manufacturer of these products as far as I am aware even recommend the use of lithium let alone say that it is necessary.

Another case of a "solution" to a problem that does not exist? As I noted earlier there seems to be confusion about the properties of a product and the benefit these give in a specific situation. So, yes the voltage drop may be smaller, but in this application (windlass ) a LA battery at a fraction of the price is more than adequate. So no benefit in going to the expense of lithium together with the changes required to the exiting system to charge it.

 

[Refueler]

I was looking at it from a cell perspective. When you buy a drop in battery, often the BMS is rated lower than the cell capacity. So you might see a 300Ah battery with a 200A BMS. If you fit 3 of such a battery in parallel, you don't have the restriction of the BMS anymore. You get 600 A continues maximum charge or discharge. Winston cells, the RR of lithium, can do 3C but very few cells from other manufacturers can do this. EVE, CATL both do 1C charge and discharge. It pretty normal.

For cell longevity - it makes sense to restrict BMS to less than max cell capability.

It sounds though that the C rating you quote are more the rate decided by the BMS rather than the cells themselves.

Not being difficult - but C rate needs to be quoted along with capacity to actually mean anything in terms of what amps you can pump in / out. C rates also have a continuous and a burst rate ... luckily BMS will not allow burst rates - but they are a factor if someone was to start creating own setups.

 

[geem]

N

For cell longevity - it makes sense to restrict BMS to less than max cell capability.

It sounds though that the C rating you quote are more the rate decided by the BMS rather than the cells themselves.

Not being difficult - but C rate needs to be quoted along with capacity to actually mean anything in terms of what amps you can pump in / out. C rates also have a continuous and a burst rate ... luckily BMS will not allow burst rates - but they are a factor if someone was to start creating own setups.

The rating I am quoting is the cell C rating. Have a look at the spec sheet for a fogstar drift 280A battery. You will see that it has a maximum charge and discharge of 200A. The nominal capacity is 280Ah. This is a battery I would buy if I was in the market for a drop in. They use Eve cells and a decent BMS with Bluetooth. They are a little expensive compared to building your self. I can buy Eve cells in the USA for $105 each. 8 of these and JK BMS gets me a 280A battery at 24v for less than $1100US.
Lots of the cheap batteries on .eBay are junk. I have seen inside a few and a really would not want one on my boat.

 

[Refueler]

N
The rating I am quoting is the cell C rating. Have a look at the spec sheet for a fogstar drift 280A battery. You will see that it has a maximum charge and discharge of 200A. The nominal capacity is 280Ah. This is a battery I would buy if I was in the market for a drop in. They use Eve cells and a decent BMS with Bluetooth. They are a little expensive compared to building your self. I can buy Eve cells in the USA for $105 each. 8 of these and JK BMS gets me a 280A battery at 24v for less than $1100US.
Lots of the cheap batteries on .eBay are junk. I have seen inside a few and a really would not want one on my boat.

G - think you misunderstand me ...

I'm not about the batts you use etc. My point is that there are many out there considering LiFe batts swap and they need to be careful about the specs ...

Your posts about your cells are good - but those who are coming to it from zero knowledge should understand what C rating really is. OK - so they can go to a seller and told - you can charge at xxA and discharge at xxA ... but that in itself is not enough - they need to understand where those Amp rates come from. Especially if they are DIY minded !!

Many are coming from Lead Acid use and the casual way we throw chargers at LA is not recc'd for Life ... as you well know.

Those with the knowledge / experience of using LiFe - need to make sure we impart the full info ... to help others not make mistakes.

 

[geem]

Mine came from China. $591 delivered to the boat in Portugal, 4 x CATL-LF302Ah-3.2V.
450UKP But just the cells, fuse cost as much as one of the cells. Rest of the bms was mostly stuff onboard already, voltage sensors etc. Though splashed out on no yet fitted latching relays, over a year & cells still closely matched. Balanced once when fitted.

But there's not really much to be gained looking a cost really, so many variables on different boats.
Another unusual cloudy day here but won't bother running the genny, only just under 30% soc so that will be fine til the morning. Lead acid I would have been burning loads of juice running the genny or even worse the main engine for hours very week trying to get lead acid back to really 100%. Hours of noise & fuel to get that last few Ah in.
Or watch them die.
And no one knows how long LiFePo4 will last with light use on a boat.

I am guessing you purchased a class T fuse and holder. I did the same, but for my second battery, I realised we could use a different fuse that has the same or higher AIC. NH00 fuses are about £8. Fuse holder about £20. Readily available in the UK and Europe

 

[geem]

Because you will fry the alternator unless you use a regulator or a B2B. Solar is OK with an appropriate regulator. It is a complete misconception that you can just replace LA with lithium, although now it is becoming more practical as the lower cost of batteries mitigates the cost of the additional charging management to fit them.

If you buy an Epoch battery, it is almost drop in. They include a high quality shunt and class T fuse built into the battery. They also have cabling to communicate directly with a Victron system. You may still need to do some reconfiguring of the electrics but their drop in is a step in the right direction.

 

[Tranona]

If you buy an Epoch battery, it is almost drop in. They include a high quality shunt and class T fuse built into the battery. They also have cabling to communicate directly with a Victron system. You may still need to do some reconfiguring of the electrics but their drop in is a step in the right direction.

Had a look, but the Victron cabling seems to only be on the 300Ah. As you say nearer drop in than others, but still a long way from worth doing in the OP's situation of just replacing an existing windlass battery.

 

[mattonthesea]

A 300Ah will cost you £850. You then have to add on all the other components such as smart shunt, fuse and holder and possibly a dc/dc charger

Of course you then have to buy an inverter and induction hob (and all the cabling and fusing that goes with this) because you didn't realise how good LiFePo4 was and Calor are teasing us with supply issues!

 

[geem]

Of course you then have to buy an inverter and induction hob (and all the cabling and fusing that goes with this) because you didn't realise how good LiFePo4 was and Calor are teasing us with supply issues!

We last bought propane in the summer last year. Still on the same bottle. Full time living aboard. It gets used on the oven about 3 times a week. That's it