What count as a cycle (battery life)

[john61ct]

Originally Posted by a64pilot

yes maybe you shouldn’t push a button and go to town, but you don’t have to watch and anything.

I just meant the voltage needs to be in range, and don't just let a non-adjustable "too smart" charger do their canned automatic conditioning.

So well-supervised by the owner to start, with a great adjustable charger after that may well be push a button (manually) and walk away to take care of other honey-do's.


> amps drops to a very low amperage, well less than 5 amps

Since the "step 0" for a conditioning cycle is "charge to 100% Full at Absorb", that makes sense. The extra high voltage does push for a certain level higher acceptance rate, but it won't stay high for long.

The only real test as to State of Health - without very pricey lab gear - is a 20-hour load test, ideally compared to the benchmarks you conducted while commissioning or just past the break-in period.

[Dockhead]

Originally Posted by gauvins

I am currently in Europe. Varta is a widely available brand here. Their 230Ah lead acid is rated at 200 cycles .5 DoD and goes for 300 euros. Their AGM 260Ah is rated at 800 cycles .5 DoD for 680 euros.

Doing the maths, that's 23 000 Ah for 300 euros (77 Ah/euro) vs 104 000 Ah for 680 euros (153Ah/euro). So almost twice as many Ah in an AGM.

OK, so now it's clear.

You should not be looking at Varta leisure batteries, which are not designed for this purpose.

You should look at 6v golf cart batteries, which are about half the price of AGM, which are much more tolerant of abuse than either leisure batteries or AGM, and which are rated at 1200 cycles @ 50% DOD.

When people on here say that AGMs are roughly twice as expensive as FLA, they are talking about real deep discharge FLA, not leisure batteries. I would be using Trojan T105's if I could fit them into my boat, but cruisers in North America have an even better variant in the Duracell/Sams Club/Costco golf cart batteries, which are just as good but much cheaper. In Europe I think the T105 is the hot ticket.


I think there is a fairly broad consensus that the most economical type of lead-acid battery by far is a heavy duty golf cart type battery, much cheaper to use for heavy off grid purposes than AGM or gel.

It's a question whether lithium might actually be cheaper in the long run. Maybe MaineSail has an opinion on that -- he's done a bunch of testing AFAIK. What MaineSail forgot yesterday about batteries is more than any of the rest of us will ever know.

[Maine Sail]

Originally Posted by Dockhead

You are holding with the popular wisdom that you should not discharge below 50%, at least not often. What is this based on? .

As I mentioned earlier it is based on capacity testing of batteries used in the real world and the fact that those graphs are extrapolated data not actual test data. It is also data that's derived from lab numbers not actual real world use. Someday we may get to a point where we have a PSOC test that is representative of real world use but today we don't.



There is good reason manufacturers such as Trojan, Lifeline etc. suggest 50% DOD as max regular discharge, and that is to hold onto their reputation because they know what happens in the real world when you routinely cycle to 80% DOD and mix it with PSOC use..

[Maine Sail]

Originally Posted by gauvins

I am currently in Europe. Varta is a widely available brand here. Their 230Ah lead acid is rated at 200 cycles .5 DoD and goes for 300 euros. Their AGM 260Ah is rated at 800 cycles .5 DoD for 680 euros.

Doing the maths, that's 23 000 Ah for 300 euros (77 Ah/euro) vs 104 000 Ah for 680 euros (153Ah/euro). So almost twice as many Ah in an AGM.

You're comparing at best a flooded dual purpose or starting battery with an apparently deep cycle AGM product. For a more "apples to apples" comparison you should compare a Varta deep cycle golf car battery to the AGM. Varta is a Johnson Controls product and JCI batteries are not considered top of the line by any means here in the US. They are a brand that simply gets relabeled such as Wal*Mart etc.. Their golf car batteries are not horrible, it's a very competitive market, but also not the ones I'd reach for first.

[john61ct]

Originally Posted by Dockhead

I would be using Trojan T105's if I could fit them into my boat, but cruisers in North America have an even better variant in the Duracell/Sams Club/Costco golf cart batteries, which are just as good but much cheaper.

Well maybe not **quite** as good. I'd pay a 15% per-AH premium for the Trojans including driving costs. The RE version maybe as much as 50%.

_______
> What MaineSail forgot yesterday about batteries is more than any of the rest of us will ever know

Absolutely, and it's been a while, so let me express a big

Thank You Rod!

on behalf of the community.

And encourage those that can, to periodically donate to help defray his website costs

https://marinehowto.com/about/

I just did, and try to do so at least quarterly.

[john61ct]

Originally Posted by Maine Sail

Varta is a Johnson Controls product and JCI batteries are not considered top of the line by any means here in the US.

I have yet to find a JCI batt I would buy for deep cycling use, personally.

Would be interested to learn of the exceptions that prove the rule.

[Pete7]

Originally Posted by john61ct

So look at other brands that make better FLA.

Rolls sells internationally.

True, but expensive in the UK and worse in Europe. Difficult to justify which is why folk this side of the pond use Varta owned by Johnson Controls and made in the EU I think.

Rolls Series 5 Batteries | Barden UK

[Dockhead]

Originally Posted by Pete7

True, but expensive in the UK and worse in Europe. Difficult to justify which is why folk this side of the pond use Varta owned by Johnson Controls and made in the EU I think.

Rolls Series 5 Batteries | Barden UK

The Varta "leisure" batteries, widely used around here, are absolutely dreadful, and I'm speaking from experience. They just fall apart the first time they are seriously challenged with a minor accident. I doubt that they are any better than ordinary starting batteries. They are fine for weekend boats which are sailed only from marina to marina, but for any kind of serious cruising or being off grid -- fuggedaboutit.

But Varta are not the only batts available here. You can get Trojans, and the light duty ones like I have are only about 30% more expensive than Varta carp, and last at least 3 times as long (and they are actually rated for exactly 3x the cycles). You can also buy a wide variety of golf cart batts, which are the best solution of all if you can fit them into your battery boxes (I can't).

As to the Rolls batteries -- why do you think the price is unjustifiable? This one:

http://barden-uk.com/product/rolls-fs-series-6fs-400/

Looks darned good to me -- just £289 for 400 amp/hours @ 6v. Hardly more expensive per NOMINAL amp/hour than a carp £120 Varta leisure battery which gives NOMINALLY 110 amp/hours (equivalent to 220 amp/hours @ 6v). That's £1.45 per amp/h versus £1.10, but you've got at least 30% more usable power in the Rolls than the nominal ratings indicate (because you can confidently discharge it lower), and plus it will last 6x (!) as long according to the ratings, and probably much more than that in real life.

That Rolls battery is an absolute bargain in terms of real cost per amp/h stored, compared to the Varta. I just wish I could somehow fit them!!!

[Pete7]

Or lift them

I think the batteries you have are probably a good bang for buck at the moment. £150 incl delivery is a good price and the same as the Varta 110AH.

https://www.tayna.co.uk/industrial-b...yABEgJ2hfD_BwE

However a pair is £300. You could buy 3 of these with change for the same price and therefore not discharge as deeply.

https://www.ebay.co.uk/itm/LUCAS-105...53.m1438.l2649

Actually we could probably get away with a pair of the smaller Trojan 24TMX since we only use 60ah a night tops and then only if we have the heating on.

Decisions, decisions and need to be made soon as the 7 year old Varta 110ah
batteries may not go on much more.

[john61ct]

Industrial applications - floor scrubbers, forklifts and most easily, golf carts are where to look.

Heck Sonnenschein makes excellent GEL batteries, come from that part of the world.

It is false economy to buy batteries for deep cycling usage, that will only last a few years even if properly cared for.

Price per AH is not important, price per AH **per year** is critical.

If they're going to get some abuse, then even more important they be robust.

[cuffy]

My Fountains Pajot was delivered with Varta professional deep cycle agm. Now 6 years old and still going strong. First 4 years on a mooring with no electricity.
Now living aboard with solar which helps greatly.

[john61ct]

That's decent, but not very long. EOL is supposed to be 70-80% remaining capacity, usually based on the 20-hour discharge rate.

Many owners stretch usage past that point.

And it is not unheard of for a relabeling brand to have different product lines outsourced to different makers.

I wonder who makes Victron's AGMs?

[a64pilot]

What about Gels?
Why have they fallen out of favor? I think quite possibly my next set may be Gels, it seems as long as you Read and follow the directions, they may have the longest life of all regular lead acid batteries.
Fireflies are to me, too unknown, for the price. I’ll wait before I decide there, but Gels have been around for a long time, and I have to assume they came too early? Before we could routinely actually maintain batteries to the .1V ?
Now that very good programmable chargers exist, the Gel story may have a different ending?

[Dockhead]

Originally Posted by john61ct

. . . Price per AH is not important, price per AH **per year** is critical...

Quite so!

For real off the grid use, leisure batteries make no sense whatsoever. The Rolls which cost only a bit more per A/H will cost a fraction of the cost per A/H/Year in real heavy off grid use.

The batteries should suit the use pattern. For marina queens which spend their whole lives hooked up to shore power and just go out on the odd weekend, leisure batteries make perfect sense.

Because if you want a REALLY accurate picture, besides considering the life span, you need to consider the time value of the investment, and so a lower initial cost will pay off if you never use the potential of the batteries anyway. Like most sailboat owners.

Yet another (!) consideration is the cost of making a mistake. Any kind of battery bank can be killed by accident -- I know, because I've done it

An expensive battery bank makes that an expensive mistake. Killing a cheap one is less tragic.

This was actually one of the main factors which held me back from a LiFePo bank a few years ago.

[john61ct]

They just got overshadowed by AGM hype.

Combined with people not realizing just how important it is to keep to the spec'd charge profiles. Overvoltage will murder them, but properly coddled - yes charge sources with customizable setpoints are critical - they'll last a decade or more.

Deka / EPM apparently licenses Sonnenshein's technology, I would only buy either of those.