Not if you are buying off the shelf batteries rather than building your own. 100Ah "drop ins" are still £500+. A pair of 95Ah stop start AGMs like mine are £280. Sure there are more expensive AGMs and batteries like Trojans, but for the "normal" weekend leisure user they have never been economically justified anyway.
I was intending to be clear that this would be something like a 30Ah drop in battery.
100 a/h drop in lithium now are £300, there’s really very little price difference now at the budget end of things.
Only in as much as £300 is very little different from £90.
The first question is, what's the true capacity of those batteries now?
I was referring to Tranona’s comment about Lithium drop in batteries being £500, as well you know.
Is it totally random, or is it a matter of how the batteries are treated, and what your criteria might be for them 'failing'?
I don't know about new builds and boat shows, but amongst full time liveaboards, in at least my experience, lithium is probably the majority now, or very close to it.
Their capacity lowered to the point that they were not worth keeping. I drop tested them using car headlight bulb. After 3 hours or so they were below 11 volts. They really didn’t work hard, usual marina sort of boat. It’s a complete mystery to me. They were replaced with a 2nd hand pair of proper deep cycle FLA’s, which are much better. When those die I shall go the lithium route, as I have recently done in my camper van.
Are they still that expensive?
As has been repeated ad naseum, a lithium upgrade makes sense if you're using your boat as a liveaboard, and may be unnecessary complication if you use it for holidays only. I get that.
That's a very good question. to which I don't know the answer. A very rough guestimate of our usage over three days would be about 230AH, and I'd guess we'd get about 80 AH from 200w of panels over two sunny days and one dull one. Yes, that would certainly be enough to bring our 120AH of batteries down below safe usage, even if they're in tiptop condition and they're a few years old.
I'm just exploring the potential benefits for a non-liveaboard boat.As has been repeated ad naseum, a lithium upgrade makes sense if you're using your boat as a liveaboard, and may be unnecessary complication if you use it for holidays only. I get that.
Just on the point of the extra equipment, that really depends. An all-singing-all-dancing setup will indeed have things like upgraded alternator, high output shore power charger, and possibly upgrades to the MPPTs, wiring, fuses, isolator, etc.
It depends on what you want the system to do. For the first two years I ran without any engine charging whatsoever. Eventually I bought a small DC-DC charger for my windlass battery, and ended up stealing it for the more worthwhile task of charging the main lithium bank. It just seems silly not to have the option I guess.
I also don't have a dedicated shore power charger, just a small portable one with crocodile clips. But I haven't spent a night in a marina since the 2nd of January anyway
If you're not already on there, the 12v Facebook group has a lot of experience on hybrid systems. Just make sure you join the right group- there's another similarly named one where they seem to think that lithium batteries are the work of the devil and will turn your boat in to the Hindenburg.
The BMS doesn't know where the charge current is coming from, neither does it care. It's the alternator that cares, Lithium will take as much charge as your alternator can output, constantly. It will run your 60a alternator absolutely flat out, but the alternator isn't designed to be run at max output continuously, it will burn out.
Yes, I am aware of those (and one or two others) but the well known names are+/- £500. I am wary of products that give so little information, make outrageous claims and need to offer extra bonus "discounts" alongside the already headline "discount" of 40%. Reading some of the reviews also raises questions. None of the reviews seem to be in boaty applications.
As far as I can tell, the BMS in these 'drop in batteries' only controls the current in as much it provides some short circuit protection, cutting off the battery if the discharge current is e.g. >50A for a 20Ah battery.
You may be right about prices falling further soon.
If you’re aware of “those and one or two others” why would you say a drop in lithium battery is £500? It’s misleading and unhelpful don’t you think? Of course you can spend more on a ‘premium’ brand, same with AGM eg Lifeline, Rolls and so on.
