Lithium costs: comparison and sanity check?

[ranger58sb]

Our oldest bank of 3x Group 31 AGM batteries is coming into its 10th season, and while it still acts normally and nominal resting voltage is still in the area of 12.6+v, I’m beginning to plan for its eventual replacement. I’d like to hear someone compare costs of a Lithium-based system, just to be sure I’m not misunderstanding the current market. I have read almost all the Lithium-related threads here, but they often wander so much I haven’t been able to pin down relevant details that would specifically apply to our situation.

So I’m planning to replace those 3x G31s with 4x 6V golf cart batteries, using Lifeline’s GPL-4CTs as a target for discussion. That would increase capacity on that bank from 300 Ah to 440 Ah, and that’s pretty much what I can fit in the same general area. (Not yet sure if I can fit the taller 6CTs, which would give a total of 600 Ah; not sure I can handle the extra weight, either.) I’m also planning to add an inverter/charger on that bank; the target for discussion is ProMariner’s TruePower CombiPS, 2000W pure sine wave inverter and 70-amp charger.

What I’d like to know is what a comparable (Ah) Lithium-based system would cost, what components would be necessary to make it all work (special charger, special controllers, whatever?) and roughly how much space it would take.

Background: Our boat has two large-ish battery banks of 300 Ah each, plus one small Group 34 battery to start the genset. Each of the two large banks starts one of the main engines, runs approx. half the house load (including one fridge on each bank), and powers additional bridge functions (electrics -- nav lights and so forth -- on the newer G31 bank, and a fairly large electronics suite on the older G31 bank being replaced).

We have a parallel switch, so if one main bank is depleted, we can tie both together to get an engine going (minimum 1250 CCA or 1560 MCA required). Lifeline advises the 4x 4CTs would be fine for this application. And then we have the genset, too. And jumper cables.

The charger is a 3-bank 40-amp “smart” (enough) system. We have no inverter now.

The overall setup is a little less conventional, but it’s simple and it works well enough for us. I do not want to change the basic setup. I’m happy with the AGMs, and I don’t particularly want to change that either unless Lithium offers an affordable advantage.

We often anchor out, but usually only for 1-5 days at a time max, and then we’re back at the dock and on shore power. More often than that, we’re marina hopping, or even more likely doing some mixture. When anchored, an hour or a bit more of generator time in morning and evening keeps the batteries charged, and we have an electric galley so we’d be running the genset to cook at those times anyway.

We don’t particularly NEED an inverter just now, but I’m planning ahead for when we have more leisure time and can stay out longer and might want some quiet access to small appliances. I believe adding additional charging capability, given that our current 40-amp charger is already tad small for our current capacity. An inverter/charger seems to speak to both of those. I have identified an area it can be installed, approx. 3 feet from the bank in question.

So what would it take in parts and $$ to replicate an approx. 440 Ah system using Lithium batteries (of some sort) ??

-Chris

[sailorboy1]

I don't have any idea what so ever.

But if I had gotten 10 years out of a set AGMs I would replace with the same and if I'm still around in another 10 years maybe the bugs will be worked out in order to consider and the cost would have come down.

Otherwise you could look up the cost of the batteries, a new charger to be able to get the most for it, the cost of a large frame alternator, the cost of the battery monitoring system.

Never mind; I think you want to be talked into it, not out of it.

[barnakiel]

And what have YOU found by contacting dealers and searching around?

I have done a small lithium project recently and the lithium capacity came at 50% of the old bank.

We had to allow for new chargers, new alternator controllers, etc. It all ended up pretty expensive but the price was not our objective in this case.

I think 50% the old capacity maybe about as good a best shot as you can get without going into your consumers and charging sources/options details.

We used batteries designed and marketed for telcom infrastructure purposes.

b.

[Nicholson58]

I think that if you search this on the CF you will find recent discussions. They looked like 50 kilobucks for us when I last looked. I believe they have come down somewhat. It would be akin to putting 500 dollar mag wheels on my '92 S10.

[nimblemotors]

Well Bozo got his 400ah pack for under $1500 I think,
and he just adjusted his existing chargers, so that is one answer.
Krusty bought a MisterVolt setup with facepaint and balloons for $15,000, so that is another answer.

[DeepFrz]

Unless you have studied all that Maine Sail has written about LiFeP04 or have studied other sources you are not yet ready for lithium. IMHO.

[SV THIRD DAY]

Originally Posted by nimblemotors

Well Bozo got his 400ah pack for under $1500 I think,
and he just adjusted his existing chargers, so that is one answer.

$1700 plus shipping to be exact.

But would I recommend this approach to others that don't have the scientist/tweaker mindset and asking the questions you have asked?

Not a chance...buy an off the shelf ready system and pay more money and don't mess with it. Are you looking for a research project or batteries?

Anwering that question to yourself honestly is very important to your cruise happiness!

[ranger58sb]

No, really don't want to be "talked into it" -- just want to be sure (if true) that this isn't yet a good time to change, since I'll be changing some stuff anyway. Or said differently: should I consider changing now, since I'll be changing other stuff too?

Also don't need any more research projects; got enough of those going at any given time anyway.

I've been pleased with the results of the AGMs, although I think I lucked out a bit in that our usage -- and recharging regime -- seems well-suited to the AGMs even if they're not all that great for long-term cruisers who are on the hook way more than we are. I hadn't appreciated that difference when we made the switch from FLAs to AGMs... but it's turned out well for us.

I've read most all Lithium-related threads -- except for all of the approx. 90 page one -- and all of Maine Sail's articles. Just can't say I understand everything. And many of the already-posted threads wander off into solar, extra controllers (is that just because of solar? or because of Lithium? or...?) so I can't really identify any additional components I'd need to consider.

IOW, I'm not trying to avoid doing my own homework... I just don't always know where to start, what's already known (by somebody), what would be specific only to our own situation. And I'm quite willing to admit I'm maybe not ready for Lithium, if that's the right answer.

(I don't recall a Bozo thread; I'll search for that, since approx. $1500 or $1700 and a charger adjustment sounds like useful info.)

Alternator? Would I need a new alternator on that engine for that bank? Is there something about Lithium that requires a Lithium-specific alternator?

Would I also need a Lithium-specific charger? Or just a Lithium profile setting on a (reasonably smart) charger? Or...?

Any other controllers, combiners, flux-gate sensors, whatever, necessary?

What's the approx. purchase cost of 440 Ah worth of appropriate Lithium cells? That would seem useful for the easiest first comparison. (Appropriate is kinda key here. Telcom batteries? Magic batteries from Tesla or whomever? How many of what cells combined into what form factor and so forth?)

From that, I think I could calculate life-cycle costs over time, given info from previous articles...



-Chris

[Maine Sail]

Chris,

You got ten years from AGM, stick with it for now..... You may also look into the Firefly Carbon Foam AGM battery which is a more sulfation resistant AGM than the standard AGM's....

[ranger58sb]

Originally Posted by Maine Sail

Chris,

You got ten years from AGM, stick with it for now..... You may also look into the Firefly Carbon Foam AGM battery which is a more sulfation resistant AGM than the standard AGM's....

Ah! Perfect answer! That cuts right to the chase, thanks very much indeed!

I'll check out the Firefly products; sounds like a good lead there, too. My current G31s are from Odyssey, but since they don't offer any 6C GCs (that I'm aware of), Lifeline seemed like a useful alternative. Nice to have additional choices.

Cheers, -Chris

[colemj]

From your description, I don't see any reason to get rid of your current batteries now.

Mark

[ranger58sb]

Originally Posted by colemj

From your description, I don't see any reason to get rid of your current batteries now.

Mark

I'll know more about their current post-winter condition after I recommission the boat, once our dock water is back on... but mostly I'm just planning ahead.

Have to admit, tales here about AGM "failures" had me feeling a little snake-bit over the last couple years, since all the doom-and-gloom was a bit disconcerting. Haven't had any issues, though, and I'm quite willing to run these down to their very last "drop" of current if I can!

-Chris

[Maine Sail]

Originally Posted by ranger42c

I'll know more about their current post-winter condition after I recommission the boat, once our dock water is back on... but mostly I'm just planning ahead.

Have to admit, tales here about AGM "failures" had me feeling a little snake-bit over the last couple years, since all the doom-and-gloom was a bit disconcerting. Haven't had any issues, though, and I'm quite willing to run these down to their very last "drop" of current if I can!

-Chris

The tales of doom and gloom mostly come from folks who are using & deep cycling their batteries while off cruising or they are on a mooring with no dock power.. By the definition of using batteries you really don't fit into the deep cycle category and fall into the very light use category..

Your use is more like an uninterrupted power supply (UPS) stand by system. This is very easy on batteries.

Originally Posted by ranger42c

We often anchor out, but usually only for 1-5 days at a time max, and then we’re back at the dock and on shore power. More often than that, we’re marina hopping, or even more likely doing some mixture. When anchored, an hour or a bit more of generator time in morning and evening keeps the batteries charged, and we have an electric galley so we’d be running the genset to cook at those times anyway.

-Chris

[barnakiel]

Originally Posted by nimblemotors

Well Bozo got his 400ah pack for under $1500 I think,
and he just adjusted his existing chargers, so that is one answer.
Krusty bought a MisterVolt setup with facepaint and balloons for $15,000, so that is another answer.

There will be some spectrum sure.

Seen here 350 Ah bank at roughly equivalent of (what would be) USD 8000 (batteries only). The dealer got talked into giving a fat discount.

Equivalent no name lithiums were priced at USD 3500.

However, as 400 Ah was the original size, we went with 210 Ah lithium. We took the quality brand.

Promised cycle life x 5 minimum. Given decent AGM @ USD 800 we ended up about 5 times money-wise.

But who trusts batteries that are 50 years old ???

;-)
b.

[ranger58sb]

Originally Posted by Maine Sail

The tales of doom and gloom mostly come from folks who are using & deep cycling their batteries while off cruising or they are on a mooring with no dock power.. By the definition of using batteries you really don't fit into the deep cycle category and fall into the very light use category..

Your use is more like an uninterrupted power supply (UPS) stand by system. This is very easy on batteries.

Good clarification and a useful analogy, thanks!

-Chris