Lifepo4 and led acid hybrid system

[Island Time 1,235]

The Standard I'm using is AS/NZS 3004.2:2014 Electrical installations„Marinas and boats

My understanding from the local electrical inspector is that this version has been sighted by the court, which makes it law. It is also the one on the official website: https://www.ewrb.govt.nz/for-registered-electrical-workers/your-licence/access-nz-standards-for-all-electrical-installations-and-appliances/ 

The 2018 version has not been sighted, and likely will not be, as it had too many issues and the replacement is, I understand, not too far away.

There is nothing in the reg that says a boat is only covered if it is connected to shorepower.

[CarpeDiem 430]

1 hour ago, Island Time said:

My understanding from the local electrical inspector is that this version has been sighted by the court, 

Thanks. I find it strange that 2008 is the only version referenced in the regulations.

1 hour ago, Island Time said:

There is nothing in the reg that says a boat is only covered if it is connected to shorepower.

Section 3 of the Electrical Safety Regulations 2010, which is the legal instrument that gives authority to the as/nzs standard states that:

the regulations do not apply to pleasure vessels unless they have connectable installations. 

connectable installation is one that is designed or intended for, or is capable of, connection to an external power supply that operates at a nominal voltage between 90 and 250 volts AC at standard low voltage.

The above clauses in the regulations indicate to me, that if you don't have AC, (or AC self generation including inverters), then the regulations do not apply to a pleasure vessel. 

 

[K4309 257]

1 hour ago, CarpeDiem said:

Thanks. I find it strange that 2008 is the only version referenced in the regulations.

Section 3 of the Electrical Safety Regulations 2010, which is the legal instrument that gives authority to the as/nzs standard states that:

the regulations do not apply to pleasure vessels unless they have connectable installations. 

connectable installation is one that is designed or intended for, or is capable of, connection to an external power supply that operates at a nominal voltage between 90 and 250 volts AC at standard low voltage.

The above clauses in the regulations indicate to me, that if you don't have AC, (or AC self generation including inverters), then the regulations do not apply to a pleasure vessel. 

 

Crikey, understanding the rules for a proper LiFePo installation sounds like a ball-ache.

Who said Lead-Carbon wasn't comparable to LiFePo? Need to add 'understanding which regulations are applicable' to the list of benefits for Lead-Carbon.

[Pecco 10]

1 hour ago, K4309 said:

Crikey, understanding the rules for a proper LiFePo installation sounds like a ball-ache.

Who said Lead-Carbon wasn't comparable to LiFePo? Need to add 'understanding which regulations are applicable' to the list of benefits for Lead-Carbon.

After reading for two days without inderstanding all of the details, I feel that going for LC makes the most sense. It is something I understand

All the rest is way to complicated.....

That s for me.....obviously🙂

[mcp 32]

18 hours ago, K4309 said:

 

Question @Island Time, how many people actually charge or have alternators big enough to charge LiFePo at 1C? 

It's not that difficult or vastly expensive to spec an engine with big alternators. The picture below is of a recent install of mine with a lithium bank being happily and safety charged at 5.8kw off a 110hp engine with 2x large frame alternators. The Alternator setup including electronics and my time was just over $1 a watt. This was excluding a mount bracket that needed to be made.

 

Totally agree with Islandtime about the comparison with lead carbon, and ill add that lead carbon have pretty bad voltage sag under high load draw in my experience. 

[CarpeDiem 430]

19 hours ago, K4309 said:

How many people actually charge or have alternators big enough to charge LiFePo at 1C?

1C is generally the upper limit for what's on the lfp market. Most manufacturers will tell you 0.5C recommended with fast charge at 1C.  That said there's a few starting to offer 3C... but these are generally cylindrical cells.

My stock Volvo Penta alternator does 115A... continually... So my design requires me to either have a minimum of 230AH of Lithium-ion or limit my alternator...

But then I have exactly the same problem with Lead CARBON - if I want to do it properly... I still have to limit the alternator OR have 345AH of weight!!  If I want to stay in the manufacturers recommended range of 0.2C I need even more lead carbon (or limit the alternator). 

Lead Carbon, unlike AGM, is not designed for unregulated alternator charging.  You need to match the system components, if you want to do it properly... 

I have seen my 100Ah Kijo Lead Carbon accept 76amps... Over double what it's rated for. I cannot do anything about it except wait and hope it doesn't burst into flames...

The key takeaway is that the problem happens with both chemistries if the system components aren't matched.

LC is not better than LFP. 

LFP is not better than LC. 

What's best/better is a solution that meets your requirements. 

[K4309 257]

1 hour ago, mcp said:

It's not that difficult or vastly expensive to spec an engine with big alternators. The picture below is of a recent install of mine with a lithium bank being happily and safety charged at 5.8kw off a 110hp engine with 2x large frame alternators. The Alternator setup including electronics and my time was just over $1 a watt. This was excluding a mount bracket that needed to be made.

 

Totally agree with Islandtime about the comparison with lead carbon, and ill add that lead carbon have pretty bad voltage sag under high load draw in my experience. 

How big / what sort of boat do you have mcp?

For me, that is a mind boggling amount of power, but for context, my boat is a 40 yr old 37fter with a 35 Hp engine. But I have mates with a 57fter who enjoy a water maker, air con, 3 fridges and freezers and of course hot and cold running water etc. Oh and espresso machine, of course

Whilst I know it is not technically difficult to set up a system to charge at 1C, my question was around how often people actually need to charge at 1C. They 'why' bit. My assumption is that charging at 0.5C would really be here nor there for most systems / people.

[K4309 257]

1 hour ago, CarpeDiem said:

The key takeaway is that the problem happens with both chemistries if the system components aren't matched.

LC is not better than LFP. 

LFP is not better than LC. 

What's best/better is a solution that meets your requirements. 

Absolutely agree with this.

The reason I'm banging on about Lead-Carbon is (in my perception) that the marine media, social media and marketing have established a narrative that Lithium is the latest and greatest, the extension being that it is the only option to consider. As we can see by this thread (and may similar threads) there are limitations to Lithium.

There are applications / situations where Lead-Carbon will be better, cheaper, safer and less complicated. Especially when someone's AGM's have died (again) and they are looking for a better option. So I guess I'm banging on about it in the interests of balance.

On overcharging / matching the charge current with the battery, I'd bet you a good bottle of whisky most AGM's die through over-charging (or related operator abuse). Especially since AGM's can only handle 0.1C.* Understanding the system properly, any system, is key. The value of a Balmar smart regulator can't be overstated in that regard.

It is interesting that there are standards for Lithium to monitor and warn of system function. I think the easiest way to cook a battery is hooking a dumb charger up to it. I would have thought a smart regulator and battery monitor would be minimum requirements on Lead Acid (AGM) installations. I guess with LA it is not so much a safety issue as an inconvenience and cost if you are constantly cooking and replacing your batteries.

*If you have a standard Volvo Penta 115Amp alternator, and it is not de-tuned, you'd need about 1,200 Amp/hrs of AGM batteries installed to keep them within the charging parameters of 0.1C. I'd hate to see how long the tail current charging is on 1,200 Amp/Hrs, or the physical size and weight of that battery bank. I'd take a punt the average AGM house battery bank is 3 to 4 times too small based on that 0.1C charging number.

[CarpeDiem 430]

35 minutes ago, K4309 said:

Especially since AGM's can only handle 0.1C.

That's an over generalization.  Some AGMs made with lower grade materials may have that limit.

A good marine grade AGM will be rated to accept unlimited alternator current.  The current is limited by the internal characteristics of the battery. 

Eg, Optima Yellowtop AGMs state "no amperage limit" when charging from alternator.  

My 75Ah Optima D31 accepts ~65Amps when charging from empty. 

Many quality AGM batteries are rated at 0.5C or above by the manufacturer.

But you pay for the privilege... 

 

[Pecco 10]

Most comments seem to have the alternator in mind as the main source of charge.

In my case, the alternator is charging the starting battery and 330w solar l charges the house bank. I don't wish to use the engine to charge the batteries.

This is limiting how may amp I can charge at right?

Is it fair to assume that daily the 330 w panel whould give me 15 amph x 8h= 120amp?

The 15amph should be the top charging that i should match a battery to, right?

So, if a 100 amp LC specs say optimal charge between 10A and 20A, that is a battery I should get?

or can the mppt controller somehow amplify... the charge delivered in example exeeding what the solar panel output is?

also, I would need two 100amp CL batteries to supply estimated power usage of 70amp daily. In paralel?

woul the 330w panel still be enough?

Hopefully it is all clear...

Cheers

 

[K4309 257]

35 minutes ago, prince rupert said:

Most comments seem to have the alternator in mind as the main source of charge.

In my case, the alternator is charging the starting battery and 330w solar l charges the house bank. I don't wish to use the engine to charge the batteries.

This is limiting how may amp I can charge at right?

Is it fair to assume that daily the 330 w panel whould give me 15 amph x 8h= 120amp?

The 15amph should be the top charging that i should match a battery to, right?

So, if a 100 amp LC specs say optimal charge between 10A and 20A, that is a battery I should get?

or can the mppt controller somehow amplify... the charge delivered in example exeeding what the solar panel output is?

also, I would need two 100amp CL batteries to supply estimated power usage of 70amp daily. In paralel?

woul the 330w panel still be enough?

Hopefully it is all clear...

Cheers

 

If you don't want to use alternator charging, installing Lithium is dramatically easier. You don't have to worry about an uncontrolled load dump blowing up the alternator when the Lithium BMS cuts off at full charge.

Others on here have more knowledge than me, but I think you can connect solar via an MPPT basically straight to the Lithium BMS. I'm sure a gizmo or two would be handy, but all the argofets, DC-DC charging, parallel lead acid and what not are not needed, as they are to protect the alternator in a load dump.

If you want 70amp/hrs for daily consumption, your 330W of solar should easily cover that. Converted to 12v, they should be giving you 27 odd amps. If the battery can accept all of that (which lithium can, as there is no tail charging current), then you would need less than 3 hours of full sun. Accounting for a bit of panel degradation over time (max 20%), and a bit of sub-optimum angle (lets say an average of 20% less output over the day), you should be still averaging about 18 amps, which to give you 70 amp/hrs means you need maybe 4 hours of sun. Short story is that should be easily achievable with a bit of generation capacity to spare.

On comparison in this application of Lead-Carbon and Lithium, both will tolerate partial state of charge, so if you don't fully charge the batteries it doesn't matter. Lithium will take all the solar power you can give it until it hits 100%. The Lead-Carbon will take all the solar you can give it in the bulk charging phase, up to about 80% of capacity. After that it has a tail charging current, where the current it will accept will drop down to zero as the charge approaches 100%. Generally on solar this is fine, as solar is quiet, and carries on charging a wee bit as the sun drops late afternoon. I'd expect the decision will come down to cost.

You can account for the lead-carbon tail charging current being slower by increasing the battery capacity. This is so you don't have to get to 100% charge. Basically size the battery bank to work between 50% and 80% DoD. You will get to 95%-100% most of the time, so this is a bonus. For 70a/h between 50% and 80%, you'd need a 230 A/h bank. 300a/h of Kijo Lead carbon was $900. I'm not across current pricing for Lithium, but to get 70A'h working capacity you'd probably want a minimum 100 Ah Lithium (not going below 20%), ideally maybe 150 Ah. I'd take a punt at battery cost at $1,500-$2,000.

Probably the big question is how many days you'd want to go for without solar charging (assuming full cloud) on the basis it is your only charge source. You'd want to increase the battery bank capacity to give you a day or two up your sleave I'd think. Are you panels rigid or flexible? the rigid panels give much better low light and cloudy conditions charging that flexible panels.

[K4309 257]

50 minutes ago, CarpeDiem said:

That's an over generalization.  Some AGMs made with lower grade materials may have that limit.

A good marine grade AGM will be rated to accept unlimited alternator current.  The current is limited by the internal characteristics of the battery. 

Eg, Optima Yellowtop AGMs state "no amperage limit" when charging from alternator.  

My 75Ah Optima D31 accepts ~65Amps when charging from empty. 

Many quality AGM batteries are rated at 0.5C or above by the manufacturer.

But you pay for the privilege... 

 

Maybe.

A lot of punters shop on price.

You would need to be fairly well educated on batteries to shop on charge acceptance. When I was looking at batteries earlier in the year I found it very very hard to find technical specifications for batteries I was looking at. The likes of Burnsco and Smart Marine certainly didn't provide that information. Some of the more specialised battery suppliers did, but most of the time I had to go and find the manufacturers specs and link it back to the exact model of battery being offered. That took a lot of time and faffing.

I don't recall seeing any AGM's that could take 0.5C, but that is more than likely that I excluded them on price before looking at their tech specs. Are the Optima's a spiral battery? For some reason I was steering clear of spiral batteries. Either I didn't understand them, or there was some other aspect around charging profile that didn't fit for me.

[Pecco 10]

3 hours ago, K4309 said:

If you don't want to use alternator charging, installing Lithium is dramatically easier. You don't have to worry about an uncontrolled load dump blowing up the alternator when the Lithium BMS cuts off at full charge.

Others on here have more knowledge than me, but I think you can connect solar via an MPPT basically straight to the Lithium BMS. I'm sure a gizmo or two would be handy, but all the argofets, DC-DC charging, parallel lead acid and what not are not needed, as they are to protect the alternator in a load dump.

If you want 70amp/hrs for daily consumption, your 330W of solar should easily cover that. Converted to 12v, they should be giving you 27 odd amps. If the battery can accept all of that (which lithium can, as there is no tail charging current), then you would need less than 3 hours of full sun. Accounting for a bit of panel degradation over time (max 20%), and a bit of sub-optimum angle (lets say an average of 20% less output over the day), you should be still averaging about 18 amps, which to give you 70 amp/hrs means you need maybe 4 hours of sun. Short story is that should be easily achievable with a bit of generation capacity to spare.

On comparison in this application of Lead-Carbon and Lithium, both will tolerate partial state of charge, so if you don't fully charge the batteries it doesn't matter. Lithium will take all the solar power you can give it until it hits 100%. The Lead-Carbon will take all the solar you can give it in the bulk charging phase, up to about 80% of capacity. After that it has a tail charging current, where the current it will accept will drop down to zero as the charge approaches 100%. Generally on solar this is fine, as solar is quiet, and carries on charging a wee bit as the sun drops late afternoon. I'd expect the decision will come down to cost.

You can account for the lead-carbon tail charging current being slower by increasing the battery capacity. This is so you don't have to get to 100% charge. Basically size the battery bank to work between 50% and 80% DoD. You will get to 95%-100% most of the time, so this is a bonus. For 70a/h between 50% and 80%, you'd need a 230 A/h bank. 300a/h of Kijo Lead carbon was $900. I'm not across current pricing for Lithium, but to get 70A'h working capacity you'd probably want a minimum 100 Ah Lithium (not going below 20%), ideally maybe 150 Ah. I'd take a punt at battery cost at $1,500-$2,000.

Probably the big question is how many days you'd want to go for without solar charging (assuming full cloud) on the basis it is your only charge source. You'd want to increase the battery bank capacity to give you a day or two up your sleave I'd think. Are you panels rigid or flexible? the rigid panels give much better low light and cloudy conditions charging that flexible panels.

Thank you for your observations, very pertinent!

My boat has what I believe is a fairly common set up. I mean N 1 switch for starting battery. N 2 switch for house and N 3 switch for both together, in case the starting battery goes flat ( i suppose).

Would this mean that if I have switch N3 on I could take alternator charge for starting and house battery at the same time?

I have a simple cut off aparatus on the starting battery that shuts off when it reaches 14.5v (?)

Would this a good enough redundancy to charge a house battery in case of low light or say solar pannel faliure???

 

[Frank 157]

8 hours ago, CarpeDiem said:

That's an over generalization.  Some AGMs made with lower grade materials may have that limit.

A good marine grade AGM will be rated to accept unlimited alternator current.  The current is limited by the internal characteristics of the battery. 

Eg, Optima Yellowtop AGMs state "no amperage limit" when charging from alternator.  

My 75Ah Optima D31 accepts ~65Amps when charging from empty. 

Many quality AGM batteries are rated at 0.5C or above by the manufacturer.

But you pay for the privilege... 

 

Below is a summary comparison of the different battery types, LiFePo  seems to score heavily in all categories. Our LiFePo has 330 Ah and we run an 800W microwave , 1200 W kettle and 1000 W induction top plus the usual sundry items like fans, lights etc. We have 440 W of Solar and a DC to DC charger, as far as I can tell the Solar has been sufficient so far but it might be different in the SI in Autumn. The array is wired in series as I was told the Higher Voltage provides better charging when the sun is low. We experimented one day by using all the appliances like there was no tomorrow and kept the lights on etc, the battery dipped to 68% and was back to 100% by the end of the day. The low internal resistance, flat charge profile and high available capacity are a real boon. Not having to set the land yacht up for LPG was also a significant win and cost offset.

All that said it was expensive and I totally get the argument that lead Acid chemistries are often the more financially attractive option particularly as it works as a  Drop in.

For interest I was quoted 14 to 16K  for a Turn Key installation at 300 Ah  including solar panels. The Electrical Inspector who issued COC certificate said that the regs on Lithium Battery installation were being updated and he had to be diligent in keeping abreast of  the latest requirements. That was in 2021 so it might have settled down by now.

 

COMPARISON OF LEAD-ACID AND LiFePO4
CHARACTERISTIC		FLA	AGM	GEL	LYTH LiFePO4	BENEFIT OF LiFePO4
Voltage		12V(2V per cell)	12V(2V per cell)	12V(2V per cell)	12.8V(3.2V per cell)	More Power
Life Cycles @ 80% DOD		500	400	1000	7100(to 70% remaining capacity)	Longer Life
Life Cycles @ 50% DOD		900	800	1400	13000(to 70% remaining capacity)	6-10X More
Weight		30kg(66.1 lbs)	32.7 kg(72.1 lbs)	32kg (70 lbs)	13.5kg(30 lbs)	<1/2 the Weight
Capacity @ 27℃	C20	130Ah	115Ah	102Ah	100Ah	Constant Power and
	C5	105Ah	91Ah	85Ah	100Ah	Energy at any Rate
	C1	74Ah	62Ah	70Ah	100Ah	of Discharge
Capacity @ 0℃		50%	68%	68%	90%	Superior cold temp
						performance
Charge Time		6-12 hours	6-12 hours	6-12 hours	1-3 hours	4-6x Faster
Maintenance		HIGH	LOW	LOW	NONE	No Maintenance
Real Cost per cycle @80% DOD		$0.67	$0.92	$0.57	$0.31	Cost over life

[CarpeDiem 430]

I am a strong advocate of Li-ion over LA. 

The Regs are stopping progress and adoption because they can't keep up with the technology.

Eg, Li-ion would be perfect as a starter battery. But the regs indirectly (or maybe directly) prevent it. There's absolutely no reason what so ever for low voltage disconnect on LTO batteries. One can take them 0v at and then recharge them to full capacity.  A Japanese company produces LFP cells that are designed to deliver 1200a for 10 seconds and are able to  peak inrush currents of 2400a - perfect to replace a marine starter battery of 700cca 

Winston, a top LFP manufacturer, sell 12v lfp batteries that do not have a BMS. The cells are precision matched at the factory and no bms is required. They will not drift. It's an absolute true drop-in lfp replacement for lead. There's no electronics, there's no app, it's just a battery... Hook it up and off you go.   But the Regs prevent adoption because they require a bms... 

The Regs should create an interesting conundrum for inspectors, how will they sign off when there's a factory Li-ion battery under the hood hooked into the starter battery of that brand new Mercedes campervan?  I suspect they will turn a blind eye. 

[CarpeDiem 430]

18 hours ago, prince rupert said:

Thank you for your observations, very pertinent!

My boat has what I believe is a fairly common set up. I mean N 1 switch for starting battery. N 2 switch for house and N 3 switch for both together, in case the starting battery goes flat ( i suppose).

Would this mean that if I have switch N3 on I could take alternator charge for starting and house battery at the same time?

I have a simple cut off aparatus on the starting battery that shuts off when it reaches 14.5v (?)

Would this a good enough redundancy to charge a house battery in case of low light or say solar pannel faliure???

 

This doesn't sound right... Can you maybe post a photo of the "aparatus"?

What do you want to achieve? What's the outcome you are looking for?

[K4309 257]

19 hours ago, prince rupert said:

Thank you for your observations, very pertinent!

My boat has what I believe is a fairly common set up. I mean N 1 switch for starting battery. N 2 switch for house and N 3 switch for both together, in case the starting battery goes flat ( i suppose).

Would this mean that if I have switch N3 on I could take alternator charge for starting and house battery at the same time?

I have a simple cut off aparatus on the starting battery that shuts off when it reaches 14.5v (?)

Would this a good enough redundancy to charge a house battery in case of low light or say solar pannel faliure???

 

I don't have the knowledge to answer your question, re if you can safely parallel you lithium.

I would argue that you either have the new Li connected solely to solar, or, if there is a way to switching it to the alternator, you need to install the full requirements to protect the alternator.

If you are in a situation where you need to parallel your house and start, you are already vulnerable to system issues. If you blow your alternator, your engine wont run, or will only run on the remaining start battery power. To recap, as soon as the Li is fully charged, the BMS shuts it off*. If the alternator is charging (which it must be for the battery to reach 100%) then there is an uncontrolled load dump, i.e. the battery suddenly stops taking the alternator power. That power has nowhere to go and the alternator goes bang.    * If you don't have a smart charging system that shuts down prior to the BMS triggering.

Note that if your primary charge source is solar, you can get a low capacity DC-DC charger, like a 10a one. These are maybe $150-$200, and if you get a victron one, you get full monitoring via blutooth and an app on your phone. The problem with DC-DC chargers are where you want to charge your Li at high current, that is where DC-DC chargers get expensive.

I don't even know if you can use Li to start an engine. I never got that far in my investigations before I found a better option. Others have commented the regs don't allow it. Note that the resting voltages of your start and a Li may mean that you can charge a start from the Li directly (resting voltage of Li 14.2, resting voltage of a flat start maybe 12v, fully charged and resting 12.8v). Also, if you have solar, why not charge you start directly?

Question: Why do you want a Lithium battery? If you have a standard, simple system, why do you want to add complexity and risk dropping high tech into it? 

The Kijo Lead-Carbon batteries will be a straight drop, will accept all the charge your solar can produce, don't need to be fully charged, can be used to parallel your start battery in emergencies, and can charge straight off your alternator. Space may be a question, but note that they can be installed on any angle or any side accept upside down. Two of mine are standing on their short end, while the third is sitting flat as normal. Lead-carbon's main application is off-grid solar.

Edit: Victron do a 9a 12v DC charger for $110, or an 18a for $190. If you really want Li, the cost of adding one of these is low, provided your primary charging is via solar due to the low charge capacity of the DC charger. It will protect your alternator though.

DC-DC Converters – Tagged "Orion Isolated" – AEP Victron Energy Store

[K4309 257]

15 hours ago, Frank said:

Below is a summary comparison of the different battery types, LiFePo  seems to score heavily in all categories. Our LiFePo has 330 Ah and we run an 800W microwave , 1200 W kettle and 1000 W induction top plus the usual sundry items like fans, lights etc. We have 440 W of Solar and a DC to DC charger, as far as I can tell the Solar has been sufficient so far but it might be different in the SI in Autumn. The array is wired in series as I was told the Higher Voltage provides better charging when the sun is low. We experimented one day by using all the appliances like there was no tomorrow and kept the lights on etc, the battery dipped to 68% and was back to 100% by the end of the day. The low internal resistance, flat charge profile and high available capacity are a real boon. Not having to set the land yacht up for LPG was also a significant win and cost offset.

All that said it was expensive and I totally get the argument that lead Acid chemistries are often the more financially attractive option particularly as it works as a  Drop in.

For interest I was quoted 14 to 16K  for a Turn Key installation at 300 Ah  including solar panels. The Electrical Inspector who issued COC certificate said that the regs on Lithium Battery installation were being updated and he had to be diligent in keeping abreast of  the latest requirements. That was in 2021 so it might have settled down by now.

 

COMPARISON OF LEAD-ACID AND LiFePO4
CHARACTERISTIC		FLA	AGM	GEL	LYTH LiFePO4	BENEFIT OF LiFePO4
Voltage		12V(2V per cell)	12V(2V per cell)	12V(2V per cell)	12.8V(3.2V per cell)	More Power
Life Cycles @ 80% DOD		500	400	1000	7100(to 70% remaining capacity)	Longer Life
Life Cycles @ 50% DOD		900	800	1400	13000(to 70% remaining capacity)	6-10X More
Weight		30kg(66.1 lbs)	32.7 kg(72.1 lbs)	32kg (70 lbs)	13.5kg(30 lbs)	<1/2 the Weight
Capacity @ 27℃	C20	130Ah	115Ah	102Ah	100Ah	Constant Power and
	C5	105Ah	91Ah	85Ah	100Ah	Energy at any Rate
	C1	74Ah	62Ah	70Ah	100Ah	of Discharge
Capacity @ 0℃		50%	68%	68%	90%	Superior cold temp
						performance
Charge Time		6-12 hours	6-12 hours	6-12 hours	1-3 hours	4-6x Faster
Maintenance		HIGH	LOW	LOW	NONE	No Maintenance
Real Cost per cycle @80% DOD		$0.67	$0.92	$0.57	$0.31	Cost over life

I'm sorry but isn't this comparison chart a nonsense?

For life cycles, they are assessing FLA, AGM and Gel to 80% DoD, but for Li they say "70% capacity remaining", which is 30%DOD, isn't it?

Then they use those numbers to present the 'Real Cost per cycle @80% DoD' as more than half as much for Li.

Accept it's not 80% DoD, its 30%. If you run any of those other battery technologies to 30% DoD they will last for ages as well. It makes the comparison a complete nonsense.

[harrytom 643]

56 minutes ago, K4309 said:

I don't even know if you can use Li to start an engine.

simple answer NO there is a risk to battery supplying high amps in a short burst,just asked the boy,his field.

[Frank 157]

My local marine electrician wryly commented that most batteries don't die from natural causes but rather  they are murdered by the owners