Simplest and cheapest pure lithium system

[Josephcrawl]

What's the easiest and cheapest pure lithium system design for starting and charging from a diesel?

Is there anything that will allow charging from a stock alternator that isn't a lead acid battery and a dc to DC charger?

Is it possible to get enough CCA with standard 12 volt lithium pre made batteries?

[BlueH2Obound]

https://dakotalithium.com/product/da...ttery-1000cca/

But you're still going to have to modify the charging system (alternator in your case) so that it will play well with LiFePO4 batteries.

Oh, and by the way, you mentioned easy, cheap, and Lithium. Which ONE do you want?

[Josephcrawl]

Originally Posted by BlueH2Obound

https://dakotalithium.com/product/da...ttery-1000cca/

But you're still going to have to modify the charging system (alternator in your case) so that it will play well with LiFePO4 batteries.

Oh, and by the way, you mentioned easy, cheap, and Lithium. Which ONE do you want?

Do they not make some kind of dummy battery that can take the place of the lead acid with the DC to DC charger?

And yes I want all three

[wholybee]

There is an old saying, "You can have done cheap, fast, or well, choose any two."
Choose cheap Lithium, easy Lithium, or Cheap and easy Lead-acid. Also, those terms are subjective. What is cheap to me, or what is easy to me, might not be for you.

No, there is no dummy battery to take place of the DCDC charger and lead acid. It simply doesn't work that way. The lead acid battery and DCDC charger is in itself a work around to save money of upgrading your alternator. This isn't an issue with LFP. The Lithium battery is fine, you are protecting your alternator, which is not able to maintain high currents for long periods of time. The cheapest fix for that would be to find a "stock" alternator that has a temperature probe and will regulate itself at a safe temperature. They exist, but are not common in boats, more common in trucks and RV's. But you need to know what you are looking for.

As for starting, the issue is the BMS. All Lithium cells will easily start an engine. The BMS in most drop-ins (except a few expensive ones) will not. This is trivial to solve if you DIY your own, but then you probably don't meet the "easy" part.

[sailingunity]

Amongst the cheap lithium batteries, I've heard good things about SOK, they even make a "marine" grade version. https://www.us.sokbattery.com/produc...y-marine-grade

Sterling and Balmar both make inexpensive alternator protection devices, that will protect the alternator diodes if the battery's BMS decides to cut off charging. Alternators have sub-optimal regulators for charging lithium batteries (or any battery really), so a lithium compatible charge controller would be recommended.

[Josephcrawl]

Originally Posted by sailingunity

Amongst the cheap lithium batteries, I've heard good things about SOK, they even make a "marine" grade version. https://www.us.sokbattery.com/produc...y-marine-grade

Sterling and Balmar both make inexpensive alternator protection devices, that will protect the alternator diodes if the battery's BMS decides to cut off charging. Alternators have sub-optimal regulators for charging lithium batteries (or any battery really), so a lithium compatible charge controller would be recommended.

I have SOKs for my land based house batteries and so far I'm pretty happy with them but it's only been a few months.

I wonder if something as simple as a high wattage resistor would help reduce the current flow from the alternator.

I'm fairly confident that two soks in parallel with a max amperage of 230 would be able to handle the starter surge on my 3 cylinder diesel.

[wholybee]

Originally Posted by Josephcrawl

I have SOKs for my land based house batteries and so far I'm pretty happy with them but it's only been a few months.

I wonder if something as simple as a high wattage resistor would help reduce the current flow from the alternator.

I'm fairly confident that two soks in parallel with a max amperage of 230 would be able to handle the starter surge on my 3 cylinder diesel.

No, to both statements.

[Josephcrawl]

Originally Posted by wholybee

No, to both statements.

So you've tried both things and they didn't work? Or are you just speculating?

[sailingunity]

I would add that "cheap" and "boat" and "lithium" probably shouldn't be used in the same sentence.

I went with Kilovault batteries, they represented the best value among the "marine" brands (BattleBorn, etc.) and came recommended by marinehowto based on the requirements some insurance companies have, here is an excerpt (sans images):

Always Check with your Insurer First

The image below is from Markel, one of the largest insurers of boats in the USA.I can’t help you with under educated ignorant insurers other than to say “ask first”!

Lie on this document & you’re not covered.

Important:
This insurer wants to see a US company, on US soil so they have someone to go after should an accident occur. This is why they demand a company based in the US.

Batteries such as Kilovault (MA), Lithionics (FL), Battleborn (NV), Epoch (SC) Dakota (ND), Relion (SC), Mastervolt (WI), Victron (ME), Trojan (CA), Lifeline (CA) etc. would all meet this criteria.

Batteries that come directly from China such as REDODO, AO Lithium etc. Would not meet this criteria.

There are still many insurers who allow LFP but please check with them first!

[JBP]

I think with the current state of technology the easiest, cheapest, simplest configuration to support conventional starting and charging is still a lead starting battery and a drop in LiFePO4 for the house bank. Possibly with a dc dc charger and/or solar/shore charger.

[sailorboy1]

I feel posters should stop using the word "cheap". It should be be "inexpensive" or "crap".

I have 4 100ah inexpensive LFP drop in batteries I got off Amazon for $1319 (includes shipping $0 and Fl sales tax).

I installed them just like my old lead acid batteries and all I changed were charger (solar, electric, alternator) settings. I do have a lead acid start battery still and it would protect my alternator if all 4 LFP BMS disconnected, which they should never do as the alternator is set to 14.0V. The alternator is belt reduced, mainly for belt loading considerations, that also reduces the alternator heat. Plus I have an alternator temp monitor that I already had. All my charging sources go to my house LFP and feed the start battery via a FET isolator.

I changed nothing physically on my boat. Everything been working so well I sometimes consider changing settings to be less conservative, but then remember to stop applying lead acid thinking to my LFP batteries.

[wholybee]

Originally Posted by Josephcrawl

So you've tried both things and they didn't work? Or are you just speculating?

Installing Lithium batteries in boats is not new. It's been done for 20 years now. I neither need to speculate, or try something to know that is shouldn't be done.

Some people have used a bicycle spoke to limit current from an alternator. Do I need to try that do know it is a bad idea? No, I don't. I also know how ohms law works, and what a resistor that can handle 50-100 amps of current looks like(I've used them personally), and that you can't just pull one up and Amazon and buy it. (Which is why a few people have instead tried bicycle spokes). It is also why insurance companies require Lithium to be installed by an ABYC tech.

So for the above, please don't put your dock neighbors boat at risk. And please don't file an insurance claim when your boat burns to the water, as the rest of us are trying to teach insurance companies the Lithium batteries are safe.

If you want to connect a drop in to your starter and watch it not work. Go for it. It's your money wasted, not mine.

[Pete7]

Originally Posted by Josephcrawl

What's the easiest and cheapest pure lithium system design for starting and charging from a diesel?

Could you explain what you are hoping to achieve with this?

[Josephcrawl]

Originally Posted by Pete7

Could you explain what you are hoping to achieve with this?

I would like to replace the lead acid bank I currently have with a lithium bank. I don't have space for an additional lead start battery. I know the lithiums will set me back about 2gs. My solar side will work with them no problems so that leaves the alternator. If it is possible I would prefer not to replace it. That's the long and short of it. Sounds likely I won't do anything and give the technology a few more years to catch up to reality.

[BlueH2Obound]

Just to clarify, the batteries I posted the link to are LiFePO4, and are designed for engine starting, with a BMS that allows 1000 cold cranking amps. No affiliation, just considering them for our boat start batters to replace current FLA batteries.

https://dakotalithium.com/product/da...ttery-1000cca/