Gel or Flooded?

[robert sailor]

I just went through the same decision. I started out with AGM's and they lasted around 8 years with care. Keep in mind that we are cycling everyday so you can't compare it to a coastal cruiser or weekender who have lots of dock time on a charger and batteries last longer in this environment.
I put in a set of Trojan T1275 lead acid wet cells which are 150 amp hours. Depending on your box size these may or may not fit.. I had to alter my box to get then in including the height but it wasn't that much work for me at the time. Size is L 12.96 W7.13 H 10.7. I'm carrying 3 of them and we are set up to be very efficient in our power use. We use solar exclusively for battery charging and main engine if no sun.
I got 6 years out of 1 in the bank which I pulled early as I was getting a bad cell and carried on for another year using the last 2 which lasted 7 years. I do service and top up the batteries each month and I equalize them every month or two as well.
We are in Honduras at the moment and you really pay a premium for agm or gels down here so this last year I went back to wet lead acid as the cost benefit ratio is just too cheap compared to the fancy stuff. I've also used these types of batteries for years so I'm very familiar with them. I like to charge at high voltages initially because these will easily take it and it does speed up the process somewhat. I can go as high as 14.8v but my normal bulk charge is 14.6v and over time dropped to 14.4v and floating at 13.2v. Good luck in your decision.

[a64pilot]

I have one bank, it’s actually two but combined with the battery switch.
I don’t believe in a separate starter bank.
I currently have 6 Lifeline GPL4CT’s. They have not done as well as I had hoped, perhaps that is my fault as there were a couple of instances early in that likely reduced their lifespan.

It’s a 660AH bank, that tested out as 600 AH a year or two old and stayed at 600 AH through all of last year, then for some reason after sitting on float at 13.3 V for six months just before we left to go cruising this year, they test out at 500 AH.

Now by test it’s not a real honest to god capacity test, it’s comparing my Smart Gauge SOC to actual AH used, but also the SOC / voltage under use chart published by Lifeline agrees, so I feel certain that I lost 100 AH last year sitting on float.
I assume this sudden 100 AH loss of capacity to be an indicator of approaching failure.

However I bought them direct from Lifeline after a pretty long conversation with one of the Godfrey’s. (I had been trying to get their Concorde aircraft battery in the aircraft we manufactured so I had contacts with them)
Anyway in that conversation with him, he had told me to expect five years of life, and that was I believe five years ago.
However my use wasn’t as severe as I had planned, but then there were a couple of battery killing incidents that I hadn’t planned either.
I’m not saying they are a bad battery, I likely killed them.

I could go that way again I guess, they are roughly $3 an AH.

[a64pilot]

Originally Posted by rslifkin

In the US, I'm pretty sure the East Penn made gel batteries use the same tech as Sonnenschein, as they licensed the tech years ago. And East Penn makes pretty good batteries in general.

I had heard that myself.

East Penn is Deka isn’t it? Sort of GM / Chevy?

[CarlF]

Over two boats I've had:

Standard AGM - lasted two years

Deka Gel - lasted five years and going strong when I sold the boat. Great battery.

Lifeline AGM - lasted 2.8 years despite never going below 50% and fully charging at least once a week. Most people who's Lifelines lasted a long time seem to plug in at a marina most nights or run their engines a lot.

Firefly - at 3 years they still test above the new AH spec. Expect to not replace them as long as I own this boat.

The Firefly's are a complete joy to own because I don't have to think about them. No more checking the Victron meter before bed to see if it's getting close to 50%. Don't have to tell the wife she can't use the toaster for breakfast without starting the genset. Fast bulk charge at 14.7v to over 90% (unlike Gel). Never consider a night at a marina just to plug in the charger since PSOC is not a factor. I installed 80% of the Firefly AH than I had in the AGM. Could have gotten away with a little less but for me it's worth the money to not think about the batteries.

It's hard to argue with the flooded battery low cost but the extra cost of a Firefly is a very low percentage of the costs of owning and operating a cruising boat.

[rslifkin]

Originally Posted by a64pilot

I had heard that myself.

East Penn is Deka isn’t it? Sort of GM / Chevy?

East Penn makes a few brands. Deka is their house brand, but they also make the West Marine SeaVolt and SeaGel batteries (at least the AGM and Gel ones). And they make Duracell and a couple others too.

[belizesailor]

Originally Posted by a64pilot

Here is the issue, Gel is almost certainly “better” no maintenance and almost certainly lasts longer.
Due to sizing constraints, I’m pretty much stuck with a group 31 battery, and in that size you can get a good quality flooded battery for $1 an AH.
Gel costs roughly three times as much.
So for a 600AH bank it’s $600 for flooded and $1800 or more for Gel.
I say more as I’ve not really researched shipping costs etc, the flooded I can pick up myself at Sam’s club so I know it’s $1 an AH, less tax.

So is Gel worth three times or more cost? Will a group 31 Duracell (Deka) flooded battery last five years in actual use?

I want Gel, but am having a hard time convincing myself it’s worth the additional cost

Are u sure the cost differential is really just due to battery chemistry? There are some very good quality gels out there which are true deep cycle batteries (not just labelled as such). There are a lot more lower quality FLAs on the market.

Youve probably read MainSail on this subject right?

My last gels lasted 14 years. I doubt I will get half of that out my current AGMs...some of that is my fault, some is that I think AGMs really are not a good fit for typical actual cruising use.

[steamgoat]

My Duracell EGC2 fla batteries died last week at 7 years. Over the last 3 years they used one to one and a half liters of water per month. Just replaced with US batteries 220 amp 6v golf car, delivered to the marina, $120 each.

[Compass790]

Our old Crown 225 A 6v FLA's need watering once a month in fulltime use & the pair probably take close to 1.5 litres. We use them for starting as well. Allegedly the older they get the more they drink.
Can't comment on gels as I haven't owned them. Would like Lithium for the weight saving if I could.

[chrisr]

we use sealed lead acid (SLA). no servicing / no top up. main advantage for us is cheap, however if you are in an isolated location and need to replace a battery, obtaining even gel (let alone lithium etc) is going to be difficult / slow / expensive.

every corner store has SLA

cheers,

[Dockhead]

If you're not going to do LiFePo4, then flooded all the way. Golf cart batts GC2 are by far the best value in lead batteries. They are tough and resistant to abuse and last a long time. You will destroy gels in one instant if you get the voltage wrong.

[Pete7]

Originally Posted by a64pilot

9.75” is really pushing it, it’s actually about .25” too tall.

That's your limiting factor, not type or price etc and reduces your options substantially. What is on top of the battery compartment and could it be lifted 1.5" to give a better fit for a larger range of batteries?

You're not the only ones with this height issue, we have a berth on top of the battery bank with limited headroom under the cockpit so modifications would be tricky. However, coastal cruising holidays and weekends with solar means we can get away with 12v FLA, therefore no need for major changes, cheap and cheerful works for us.

Pete

[s/v Jedi]

If you go gel then get the right ones. If they don’t fit then go for Lifeline, Firefly, Battleborn (good to best, expensive to more expensive)

Here’s the good stuff (picture attached as well): A600

[billknny]

Don't discount the Firefly option... I think they are the most cost effective solution for full time, off the grid cruising. Not the cheapest, but well worth the upfront capital investment. For us, they have worked as advertised, and already have proved they were worth the cost over other LA options.

Our experience: https://fetchinketch.net/boat-projects/battery-upgrade/

My personnel take on the economics of Firefly vs Lithium: https://fetchinketch.net/2019/09/24/...-marketing-bs/

No commercial interest, just an engineer's number crunching.

[blubaju]

there are many flavors of GEL, even within one brand, check the Sonnenschein/Exide homepage, I used upon suggestion of our dealer, he sells AGM too and all kinds of flooded stuff, I used Sonnenschein A500, and they last 14 years. Why GEL: they are much more tolerant to deep discharging and Catamarans do not want heavy load, so our battery bank was undersized. Wanted to safe many and difficult to purchase I bought AGM, but they died after 5 years. If bad again, I'll switch to Lithium.

[contrail]

Originally Posted by rslifkin

In the US, I'm pretty sure the East Penn made gel batteries use the same tech as Sonnenschein, as they licensed the tech years ago. And East Penn makes pretty good batteries in general.

Yes, they were (are?) called Prevailers.