Lead Acid, AGM vs Lithium Ion batteries

[GregOddity]

Are these Li-on batteries the same as one gets in model RC aeroplanes?
If they are then i would not touch them with a barge pole.
I have seen one burst into flames when slightly over charged & it burnt through a wooden table & fell to the floor.
I have heard of a number of similar accidents.

Yes, and NO, RC sets are (some that I have seen) explored to the limit to extract every little electron and free Ion floating inside. That led to some very real airborne flameout incidents. This days the batteries we are discussing are more commonly used in a lot of other applications where a fire hazard risk cannot be taken lightly. Vaping devices consume a huge number of this batteries and cars like tesla also use them as the power bank. They would be more then capable of powering a boat, if a controller existed to control the level of charge and heat generated while charging, i.e. diverting the charge at a certain temp to the next battery to allow heat dispersal and continuously charge the bank.
Sadly. no controller charging unit is available for such a large number of batteries needed. (HINT HINT ! )

 

[Saguday]

I have a Tesla and can attest to the wonderfulness of modern lithium batteries. However, I wish you could buy the Tesla 'packs' of 18650's they put together along with some of the control trickery to charge them, as a smaller unit so you could re-purpose them somewhere else, like in a boat fr'instance.

There must be a large potential secondary market for them, although given they can barely make enough to keep up with demand in the EV market it may be a while before we see anything available. It might be a good use for old electric car batteries, recycling them for other less critical uses. Nissan and others claim they use old EV batteries for domestic solar/battery systems and I would imagine they would also be good enough for use in boats for house battery banks.

 

[pvb]

There must be a large potential secondary market for them, although given they can barely make enough to keep up with demand in the EV market it may be a while before we see anything available. It might be a good use for old electric car batteries, recycling them for other less critical uses. Nissan and others claim they use old EV batteries for domestic solar/battery systems and I would imagine they would also be good enough for use in boats for house battery banks.

Tesla devised the Powerwall to make use of recycled ex-vehicle batteries.

 

[JumbleDuck]

I have a Tesla and can attest to the wonderfulness of modern lithium batteries. However, I wish you could buy the Tesla 'packs' of 18650's they put together along with some of the control trickery to charge them, as a smaller unit so you could re-purpose them somewhere else, like in a boat fr'instance.

You can! That's the Tesla Powerwall I referred to - a snip at £5,970 plus installation.

https://www.tesla.com/en_GB/powerwall

 

[William_H]

William

I have a Perkins 4 108 engine and I intend replacing the 12V 40A(?) alternator with a 24V 60A alternator. I am using 24V for anchor winch, fridge/freezer, bilge pumps (X3) and macerator.

I worry when I see that the L-ion batteries have to be charged in a certain way and you mustn't flatten them: I really don't understand the technology. I've yet to do more reading of these comments but I think I'll go for AGM but because of the weight I'll mount them fairly close to amid-ships. (I've seen some of the Roberts Mauritius 43 ft yachts just about dragging the transom in the water because people have installed oversize motors). I think an auto pilot is a high priority so I'll spend the money on that.

I don't know where I read you couldn't start the motor with the L-ion battery. Maybe it was because the batteries couldn't withstand a large current draw because they were storage batteries?

Thanks everyone for your opinions, I've got a bit more reading to do though

Clive Cooper

Hi Clive
I imagine or expect that you will convert the whole engine system to 24volts. There will be great advantages in starting the engine with 24v battery. However it is conceivable (I might be wrong) that you can use the 12v starter on 24v without damage. However you would need to change or convert engine instruments warning lights etc to 24v.
Incidentally I have been talking to a friend with a 30 fter about remote engine operation from the steering position. If it is not too late for you, it might be good to fit all engine controls outside at wheel. ie start and stop and power (ign) on.
Or perhaps from your post you may be planning to start engine (and instruments on 12v) recharging the 12v battery from a power converter. (buck regulator) Keeping 24v for just anchor winch fridge etc. That may be feasible but a bit odd. I think better if necessary to just have a buck regulator for the instruments. Either get a starter for 24v (should be common) or just hit the 12v starter with 24v. Anyway good luck with it all. I reckon you will find electrics and lots of other things evolve on the boat rather than try to get it all done before launch. Real life use can then guide you on what you need. olewill

 

[Saguday]

You can! That's the Tesla Powerwall I referred to - a snip at £5,970 plus installation.

https://www.tesla.com/en_GB/powerwall

Am aware of Powerwall, but not sure it’s the right form factor for boaty use??

 

[coopec]

Hi Clive
I imagine or expect that you will convert the whole engine system to 24volts. There will be great advantages in starting the engine with 24v battery. However it is conceivable (I might be wrong) that you can use the 12v starter on 24v without damage. However you would need to change or convert engine instruments warning lights etc to 24v.
Incidentally I have been talking to a friend with a 30 fter about remote engine operation from the steering position. If it is not too late for you, it might be good to fit all engine controls outside at wheel. ie start and stop and power (ign) on.
Or perhaps from your post you may be planning to start engine (and instruments on 12v) recharging the 12v battery from a power converter. (buck regulator) Keeping 24v for just anchor winch fridge etc. That may be feasible but a bit odd. I think better if necessary to just have a buck regulator for the instruments. Either get a starter for 24v (should be common) or just hit the 12v starter with 24v. Anyway good luck with it all. I reckon you will find electrics and lots of other things evolve on the boat rather than try to get it all done before launch. Real life use can then guide you on what you need. olewill

I have been told by an auto electrician I can use 24V on a 12V starter but I'd want confirmation before I'd go ahead. (I will carry a spare starter motor as the engine would be very difficult to start by hand)

As far as engine controls are concerned the center cockpit is directly above the motor and I will shortly complete the installation of the Morse Control (single lever) for gears and throttle beside the wheel. I will be able to operate the anchor winch from the wheel also but I have yet to run the cable for the control. The motor will be able to be started/stopped from the wheel.

The instruments are above the companionway: they are rudder angle, rev counter, oil pressure, amperes and..... ? I've also run a whole lot of wires (computer ribbon type) for alarm lights (the size of a match head) - water intake pressure, exhaust water temperature and ......? Why would the instruments have to run on 24V? (I think the rev counter works off the alternator)

I accept there will be things needing to be completed (such as fridge/freezer) after the launch but the motor, batteries, bilge pumps are a must to be operational.

Clive Cooper

 

[crisjones]

This http://www.beginningfromthismorning.com/house-batteries-part-1/ is an interesting blog about using Lithium Batteries as domestic bank in an RV Bus, he decided to use the battery pack from a Nissan Leaf electric car and has configured it give about 500AH at 48V !!
Anyway the blog gives lots of very interesting info about the pro's and con's of Lithium and also gives info about the charging and discharge regimes for max life. It should answer many of your questions.
I have looked into using Lithium (LiFePo) batteries for domestic on our boat - I am convinced that they are definitely cost effective for long term liveaboard use even when you factor in the extra costs of monitoring systems and changing charging parameters etc. Here https://marinehowto.com/lifepo4-batteries-on-boats/ is another article on Li batteries on boats, very detailed and informative but it clearly makes the point that you cannot just swap from lead acid to Li, you have to design and configure the complete electrical system to suit Li batteries - it is not a simple DIY job unless you are an experienced electrician and understand all the factors involved.
We currently have 3 x 375AH Rolls 5000 series deep discharge Lead Acid to give just over 1000AH at 12V and they have served us well for over 11 years. To replace them today would cost around €3200, I can buy 400AH of LiFePo4 for around €2000, so I can spend €1200 on a BMS and associated relays, contactors and controls for the same cost as replacing my lead like for like. The Li batteries should give much higher cycle life, way better charge and discharge capabilities and save around 250kg in weight - what is not to like??
As mentioned above the fitting of Li batteries is not a simple job but if you are electrically competent it is a very good option to consider. I freely admit that you can buy much cheaper LA batteries than Rolls but you would almost certainly not get 11 years life out of the cheaper ones. The comparison between Rolls and LiFePo4 batteries is fairly equal in terms of capabilities and expected life although the testing described in the article above shows hardly any loss of capacity of the Li batteries after over 770 full charge/discharge cycles. No way would LA batteries still give 100% of original capacity after 770 cycles.

 

[coopec]

William

[I]There will be great advantages in starting the engine with 24v battery. However it is conceivable (I might be wrong) that you can use the 12v starter on 24v without damage

My B-I-L is a diesel engine fitter and he said they used 24V on a 12V starter motor for 20 years and there was no problem.

Clive

 

[William_H]

Hello Clive I just imagined that you would have a complete engine control panel like you do for volvo or Yanmar designed to run on 12v. If you have effectively built your own control panel then yes run instruments on 12v domestic if that suits. I can think that perhaps electric oil pressure gauge might need 12v. I imagine charge light will be 24v for the alternator if it has one. So each item needs to be individually assessed. Re 12v starter on 24v Yes I suspected all ok. Just a bit shy to claim outright. Just be careful if you do a lot of cranking. Strange I believe some engine manufacturers specify a max sized (AH) battery on the basis that a very big battery will hold up the cranking volts to nearer 12v compared to 9v for a smaller battery. Presumably because more volts is bad for starter motor. But of course they may just be covering them selves. good luck olewill

 

[KellysEye]

Apparently Lithium Ion batteries have stopped catching fire: http://www.bbc.co.uk/news/science-environment-41187824 For starting you are right about lead acid or the latest calcium battery both are Cold Cranking Amp batteries. In which case a Lithium Ion battery is not needed because house batteries should be deep cycle such as Trojans.

 

[PaulRainbow]

Apparently Lithium Ion batteries have stopped catching fire: http://www.bbc.co.uk/news/science-environment-41187824 For starting you are right about lead acid or the latest calcium battery both are Cold Cranking Amp batteries. In which case a Lithium Ion battery is not needed because house batteries should be deep cycle such as Trojans.

Kelly's stuck in a time warp, calcium batteries have been common place for decades. But he does really know that, i tell him every time he trots that drivel out.

 

[Tranona]

Kelly's stuck in a time warp, calcium batteries have been common place for decades. But he does really know that, i tell him every time he trots that drivel out.

Does not make the slightest difference what you tell him - on any subject he will keep on repeating the "drivel".