Gel batteries

[john61ct]

Sonnenschein is the worldwide leader, did a technology transfer deal with East Penn (Deka) which are very well respected as well.

Both should have well informed technical personnel readily available to answer detailed questions directly, as well as helping you find an appropriate dealer as close to you as possible.

Just be sure to pay close attention to the detailed charging / care specs, especially wrt avoiding overcharging, both OVP and ensuring Absorb is not held "too long" past the endAmps point.

I have read conflicting data on whether they are more or less susceptible to overtemp conditions.

They should if coddled last much longer than even the best AGM.

But of course if cruising in remote / primitive locations GEL will likely be difficult / expensive to replace.

In that scenario I'd stick to FLA GCs for value, or make the jump to LFP with a high redundancy design.

[a64pilot]

I’m not interested in LFP, not yet.
I was looking if I have to move the bank I can easily accept 16” tall batteries maybe taller.
What’s the reason people don’t use the Trojan Solar batteries?
If I move the bank I guess current battery box will become a can storage area.

[john61ct]

Trojan make great FLA, but IMO their regular GCs not necessarily much better than the Deka at $1/Ah.

Their AGM are definitely not so great, GEL prolly ditto, LFP totally new & outsourced anyway.

[a64pilot]

Why aren’t people for example using this battery? It’s rated 2,000 cycles
https://www.trojanbattery.com/pdf/da..._12_225_DS.pdf
The industrial Solar are monsters, but are rated to 3,000 cycles

[CarlF]

I had gels in two previous boats - Sonnenschein in the first and East Pen in the 2nd. Lot's of people told me how tricky gels are - but I didn't find that the case. Just don't charge at too high a voltage.

I could never get a good answer as to the best voltage. The most conservative was to not go above 14.1v temperature compensated but some gels can go to 14.4 and some even to 14.6. I just always went with 14.1v and it seemed to work fine.

While they won't charge quite as fast as an AGM, it's unlikely you have the charge capacity onboard to charge them too quickly.

Charge acceptance is slow above 90% but I didn't find it any worse than AGM.

East Penn is by far the most available gel in the US. Here's the spec sheet.

https://www.eastpennmanufacturing.co...Flyer-0909.pdf

[acem]

Looking at your case dimensions and the Prevailer spec page I think your original setup was for three DF180 batteries. With one set horizontal on the left and two set vertical (related to your drawing on my screen) they will all fit in the box with room all around for tiedown, cables, etc. Thx-Ace

[CarlF]

Have you considered Firefly's? No PSOC problem and you can discharge 80% (which you shouldn't do with Gel's).

With your odd shaped box, you'll get more usable amps than gel, AGM, or FLA.

I've had my Firefly's for two years and have paid no attention to getting them back to 100%. They appear to still have slightly over 100% of spec capacity.

[boom23]

Just as a data point, Amel uses MasterVolt Gel batteries on the Amel 50. So far (just one season), they have been great!

I do plan to replace them with LFP when they go bad, in about 10 years.

[john61ct]

Originally Posted by a64pilot

Why aren’t people for example using this battery? It’s rated 2,000 cycles
https://www.trojanbattery.com/pdf/da..._12_225_DS.pdf
The industrial Solar are monsters, but are rated to 3,000 cycles

Yes do last lots longer,

not saying wouldn't be great, but at double the weight for the Ah, and lots pricier especially if not sold locally.

T-105's are sometimes only 10-15% more than the Deka GC's, that'd be great value.

But if replacing the bank is a hideous chore, definitely worth paying a premium to do so less often.

Long as you **know** they will be getting well cared for.

[ranger58sb]

If three Sonnenschein DF180s fit (as suggested in post 21), it looks like (from that link in post 14) the Deka 8G31s would be approx the same.

Which could maybe mean Odyssey 31M-PC2150s and Lifeline GPL-31XTs could also fit, if you decide to stay with AGMs.

Not sure any of those options would be better than your current GPL-4CTs, assuming you've got four of 'em in a 440-Ah bank.

Maybe shave the underside of your battery box cover?

Seems odd to me that a Florida builder would go out of their way to install German batteries.

??

-Chris

[noelex 77]

I have experienced excellent life (10+ years) over several boats using Sonnenschein gel batteries.

I am not convinced by the claims of needing very careful charging. They were fitted to our first boat before solar regulators were available. Charging voltages were manually switched and not well controlled. They lasted 15 years!

This was with 12v batteries. The 2v versions have even better deep cycle performance and can fit in more places, especially the models that can be installed on their side. They would be worth considering for this unusual battery box shape, but some homework is needed to see what capacity will fit.

As well as Sonnenschein, the other brand to consider is Hoppecke.

[jibstay]

These are the Gel batteries I bought 3 years ago.

https://www.remybattery.com/deka-gel-4d-battery.html

Just under US$500 each, with free shipping.

They’ve been great.

[a64pilot]

Thing is though that I can be pretty excessively careful with charging without an issue, I can control pretty precisely max current and charge voltage to .1V and temp compensated at that, and can switch from absorption to float at a precise acceptance current.
So I am going to assume that even if precise charging is a concern, it’s easily met now that we are in the 21st Century and precise charging is the norm.
My boat came with a 30 amp charger that simply had one voltage output, I have no idea what it was, and it was located about 20’ away from the bank and connected to the bank via 10Ga wire. That would seem to be awfully abusive to a Gel bank to me, but it seems it worked.

[a64pilot]

Originally Posted by acem

Looking at your case dimensions and the Prevailer spec page I think your original setup was for three DF180 batteries. With one set horizontal on the left and two set vertical (related to your drawing on my screen) they will all fit in the box with room all around for tiedown, cables, etc. Thx-Ace

Thank you, now to find a US source

[a64pilot]

Originally Posted by ranger42c

If three Sonnenschein DF180s fit (as suggested in post 21), it looks like (from that link in post 14) the Deka 8G31s would be approx the same.

Which could maybe mean Odyssey 31M-PC2150s and Lifeline GPL-31XTs could also fit, if you decide to stay with AGMs.

Not sure any of those options would be better than your current GPL-4CTs, assuming you've got four of 'em in a 440-Ah bank.

Maybe shave the underside of your battery box cover?

Seems odd to me that a Florida builder would go out of their way to install German batteries.

??

-Chris

I have six, two more in another location for a 660 AH bank, average consumption from one Solar day to the next is about 130 AH, so they are discharged a little less than 25% daily.