With lithium do we actually need a dedicated starter battery?

[Fuss]

The reason it works rivet with Eve 280 cells and does not damage them is that the spike is for a millisecond and then the draw becomes acceptable. Do you know how long Eve280 cells can crank a 6l diesel when it won’t start and has fuel problems Rivet?… it’s a very, very long time.

[Fore and Aft]

Fuss if I was going down the Lithium start battery path, I could put my faith in a battery like this, but the cost $1100 US dollars is crazy.
https://www.relionbattery.com/rb100-hp

[wholybee]

Originally Posted by s/v Jedi

See, here is where our different opinions pop up:

- an electric galley can’t work on 3.5kW. Even just two induction hobs can go up to 3.6kW. You want a minimum of three 1.8kW appliances, for example a cooktop plus microwave plus coffeemaker. It should just work.

<snip>

It really depends on how big you need/want to go. You have a large and very luxurious yacht. Like you said, it is like living at home. As awesome as that is for you, you are in the minority. I have one induction hob that maxes out at 1500W. I NEVER run it that high. It just doesn't make hardly any difference. 600W is fine for 90% of my cooking, and 900W is fine for the other 10%. Two hobs could be run off a 2000W inverter. With my one hob, 1500W is enough. That is in the size range that 12V makes sense, 400Ah of battery is enough, and only 1000W of solar is enough. Which is great because my boat is only 38' and I don't have room for more battery or more solar. Or a washer/dryer, or any other countertop cooking gadgets. It is simple, but it works fine.

[Pete7]

Originally Posted by s/v Jedi

See, here is where our different opinions pop up:

- an electric galley can’t work on 3.5kW. Even just two induction hobs can go up to 3.6kW. You want a minimum of three 1.8kW appliances, for example a cooktop plus microwave plus coffeemaker. It should just work.

- Struggling with 12V house batteries with an all electric galley is never a better option. If one can’t afford an electric galley then keep with propane. You have two or three hobs plus an oven and can run it all simultaneously. You need comparable performance with electric otherwise it’s a step back instead of forward.

See, here is where our different opinions pop up

In no particular order space and money being two controlling factors. So we manage perfectly well with an electric galley on 220Ah of drop in LFP with a 85Ah FLA in hybrid config. The inverter is the latest Sterling 2kW PSW.

There is a spare 1.6kW PSW inverter. There is an identical spare dual hob induction stove. We carry spare Victron MPPTs. Single points of failure minimised.

To go to 24v from where we are now is a huge cost and a lot of work. If the current system works well, then the question is what do we gain? You have outlined the advantages above and if starting from a bare boat then yes, I can see the merit in 24v. It's a mission creep problem. Go back a decade and few would have envisaged what we are using today.

So what can't we do with 2kW? Well we can't run both induction rings (1600w), the Remoska (525w) and kettle (1000w) at the same time. However, we never needed to. We can run the two hobs and Remoska at once. Do we eat well? yes thanks and going away on the yacht means I get time to bake.

Cold bake beans? Only in another life, eating the UK equivalent of MRE rations. Could we be forced to revert to this in a complete melt down? No, we carry one single Camping Gaz 1.8kg butane cylinder and a single gas hob burner. Its not connected but could be in 15 minutes if required. However, its the ultimate fallback option.

Future plans this year? Finish adding a portable rigid 110w panel moveable to either life line side. Trial a little 45lb Minn Cota electric motor for the 2.8m dinghy. Oh and bake cakes

I certainly wouldn't want to discourage anyone from pushing the envelop even if its a hybrid mix of gas hob and induction. Particularly so on a smaller yacht with limited space and of course budget. There are some real advantages in reducing the gas usage and the need to faff around with cylinders so often. Plus cooking in a hot environment. Can't imagine cooking a leg of lamb for a roast dinner during a Florida summer.

[CaptainRivet]

Originally Posted by Fuss

Why do you have to make it so complicated and even more so with the constant thread drift. I told you rivet more than a year ago that 12v 280ah Eve lifepo4 is starting my 6liter diesel and you said it would last at most a month and would burn the boat down.
That says it all, advice should be based on you own personal experience not what you imagine or read on these forums and then re parrot.
Start your motor with the same type of lifepo4 cells that you have for your non drop in house bank, that is the only way to do it if you are space limited and plan long term cruising. The benefit, I will say in a later thread as there is enough thread drift on here already.

My advice was based on the data you were posting and that would have killed the 280AH EVE in max a month as far outside the spec of the EVE…it turned out after countless pages without clear spec of the starter, that in another thread the starter and its wattage was posted by you and are much smaller then the totally overspeced CCA requirement stated. With wrong data I can only give wrong advice…With correct starter wattage it was then suddenly much lower and fitting well within the spec of the EVE280AH and sure then it works well.

I start from 1088AH. Even better then 280AH and crank much longer…and have a cat with 2 engines so the starter of the other one is my backup. Was its original setup from factory and I kept it when going lithium.

Yes with prices of 90Euro for a grade A EVE 280AH it starts to makes sense to use this as starter or in Jedi or mine 12V hybrid starter/house or buffer setup.

With 18$ for basically new 20AH LTO Toshiba SCiB cell that can do 25C you can build a starter in 1p6S that has 20000 cycles and lasts >20 years for 108$…for the cost of a cheap FLA…there is not even the simple purchase price factor anymore to stay with lead.

[ranger58sb]

Originally Posted by ranger58sb

Are there LFP batteries that can provide 1400 CCA? And 560A continuously for 4.5 minutes?

-Chris

???

-Chris

[Wandering1]

Originally Posted by CaptainRivet

Typical mantra. You should but why should I? Please explain why?
Safety means engine must start.

You have house and dedicated starter,
I have hybrid house and a buffer bat that isolates electronics and with flip of a switch can start engine
We both are 4 weeks on anchor at the same place and unforcasted storm/squall comes in and we need to quickly move, classic liveaboard situation:
You: your house runs but your starter was not used for 4 weeks => you don‘t know if it works!!!
Me: hybrid house runs and used under load constantly=> I know 100% engine will start
The buffer isolates electronics from spikes => I see its really full, I see it runs under load constantly and it will be a reliable backup that 100% start my engine if it needs too.

Hybrid bank, cutoff is at 3.0V except starter so I cannot accidentally drain hybrid that much that engine cannot start. Goes directly onto bank with a breaker, no cut off. If starter fail breaker trips, if lights go out due to cut off I still have 80 starts left in the house till 2,5V and then another 30 till hybrid is totally drained and I can decide if it’s better to drain hybrid then boat on the reefs or if I have enough time to switch to backup…I have options, you don‘t.
And I still have a buffer that can start engine too. BMS of buffer cuts off at 40% SOC but again starter goes via breaker directly onto buffer. Again cannot drain accidentally.

Why and which benefits and advantage do I have from a battery that does nothing else then start the engine? I don‘t know if it works unless I try to start…and well 90% of boats from factory have windlass on starter that can really drain quickly the starter…

Our starter batteries have a dedicated DC/DC charger off the lithium. In addition we run our windlass from this pair of 12v batteries (24v boat). We lift the dinghy every night using the windlass off the starter batteries. We know the battery is good, every day.
Why would I want to waste money on an expensive lithium solution when lead batteries cost me £100 each? Our system is kept simple with redundancy. I don't want critical systems reliant on more electronics.

[CaptainRivet]

Originally Posted by ranger58sb

???

-Chris

Yes 1p4S 180AH Winston or 200Ah to have some headroom will do that very long. Use a BMV712 as „BMS“ with relay outputs to do LVC and HVC plus a Neey 4A active balancer which also does the cell monitoring.

[CaptainRivet]

Originally Posted by Wandering1

Our starter batteries have a dedicated DC/DC charger off the lithium. In addition we run our windlass from this pair of 12v batteries (24v boat). We lift the dinghy every night using the windlass off the starter batteries. We know the battery is good, every day.
Why would I want to waste money on an expensive lithium solution when lead batteries cost me £100 each? Our system is kept simple with redundancy. I don't want critical systems reliant on more electronics.

Use 1p6S 20AH LTO Toshiba SCiB cells cost 6x18$ so each 108$, can do 25C=500A with 20000cycles means>20 lifespan replace the lead…no single piece of electronic added. Safest battery chemistry available and That’s no money wasted…on lead

[Wandering1]

Originally Posted by CaptainRivet

Use 1p6S 20AH LTO Toshiba scrib cells cost 6x18$ so each 108$, can do 25C=500A with 20000cycles means>20 lifespan replace the lead…no single piece of electronic added. Safest battery chemistry available and That’s no money wasted…on lead

I would need twice as many cells as we are a 24v boat. So just doubled your cost. The alternator is designed for charging lead. No expensive add on regulator. More cost to control alternator output. No thanks. Will stick with my old fashioned lead.

[Fuss]

Originally Posted by CaptainRivet

My advice was based on the data you were posting and that would have killed the 280AH EVE in max a month as far outside the spec of the EVE…it turned out after countless pages without clear spec of the starter, that in another thread the starter and its wattage was posted by you and are much smaller then the totally overspeced CCA requirement stated. With wrong data I can only give wrong advice…With correct starter wattage it was then suddenly much lower and fitting well within the spec of the EVE280AH and sure then it works well.

I start from 1088AH. Even better then 280AH and crank much longer…and have a cat with 2 engines so the starter of the other one is my backup. Was its original setup from factory and I kept it when going lithium.

Yes with prices of 90Euro for a grade A EVE 280AH it starts to makes sense to use this as starter or in Jedi or mine 12V hybrid starter/house or buffer setup.

With 18$ for basically new 20AH LTO Toshiba SCRIB cell that can do 25C you can build a starter in 1p6S that has 20000 cycles and lasts >20 years for 108$…for the cost of a cheap FLA…there is not even the simple purchase price factor anymore to stay with lead.

That’s because lead gets a voltage drop that lifepo4 does not, you should know that , a 6l diesel is way beyond the spec of what most on here have.
If Eve280 lifepo4 start my 6l diesel, then it means that for 90% of the sailors on here it would be no problem at all using eve280 cells.

And the real advantage is that they are exactly the same cells as the house bank, providing redundancy for the world cruiser, redundancy, not only for starting but also for the house bank.

End of story, we don’t need these endless complicated threads that turn everyone off!

[GreenWave]

I dumped a separate start battery last year when I installed Lithum. I have three ways to start my Yanmar. The LFP house bank, a jumper from my AGM Bow thurster bank, a portable Lithium jump pack. All have been tested and used to start my engine.

If you convert from AGM to LFP that is the time to dump a separate start battery!

[CaptainRivet]

Originally Posted by Fuss

That’s because lead gets a voltage drop that lifepo4 does not, you should know that , a 6l diesel is way beyond the spec of what most on here have.
If Eve280 lifepo4 start my 6l diesel, then it means that for 90% of the sailors on here it would be no problem at all using eve280 cell.
And the real advantage is that they are exactly the same cells as the house bank, providing redundancy for the world cruiser, redundancy, not only for starting but also for the house bank.

End of story, we don’t need these endless complicated threads that turn everyone off!

Again wrong information and conclusions.
it doesn‘t matter how man Liter your engine have and how high CCA is stated. the only thing that matters is the wattage of your starter and voltage operated. The surge it can create is simply limited by the stators winding and isolation lacquer…your starter would simply melt and short with 1000A, so 1400CCA is/was way overspeced. Add to that the glow plug if your engine has one!

So if checking the specs of LFP battery for starting application, in this case need 280AH EVE and take the rule of thumb wattage/voltage=continous current x 4 = maximum surge possible before windings short out. Insecure or have a big 6l on your starter size simply get a fluke meter and measure surge with blocked fuel line so it’s not starting…
That’s on a 12V 2000W starter 170A continuous and 600A surge.
EVE 280AH due to officially datasheet 1C cont=280A , 3C peak=840A, so a 2000W starter is well in spec with reserve. A 2500W 12V starter with 210A cont and 840A peak fits too but is at the peak limit of the EVE.
That’s just the starter, if it has a glow plug you need to add that too, means a 2kw starter with glow plug fits but a 2,5KW will work but is at the limit of the specs.
As simple as that…

[mikereed100]

In reference to the original question, I keep a 100 amp AGM start battery for each engine because:
1. I already had them when I installed the LFP house bank and saw no reason to get rid of them.
2. As an eternal optimist my hope is that in event of a lightning strike that may cook the BMS on the house bank I will still be left with 200 ah of AGMs that can start the engines and run whatever electronics remain.

[rslifkin]

Originally Posted by CaptainRivet

Again wrong information and conclusions.
it doesn‘t matter how man Liter your engine have and how high CCA is stated. the only thing that matters is the wattage of your starter and voltage operated. The surge it can create is simply limited by the stators winding and isolation lacquer…your starter would simply melt and short with 1000A, so 1400CCA is/was way overspeced. Add to that the glow plug if your engine has one!

Needing a battery rated for 1400CCA isn't necessarily because the engine actually will draw 1400 amps when cranking. CCA is a measure of how much current you can draw for 30 seconds at 0* F before the battery drops below 7.2V during the test.

Because of that, CCA is generally not a concern if starting from a lithium battery, the concern is just whether you can handle the brief large inrush current when cranking starts and then the sustained starter current. Unless it's a very small battery voltage sag during cranking and the length of time it could support cranking for are unlikely to be limiting.