Rolls S-480 verses S-550

boxphotographer · December 2016

I am about to pull the trigger on 16, l16 type batteries for a 48v bank. I would like the extra capacity that the S-550 offers but I am hesitant, the extra capacity must mean that other areas of the battery are sacrificed? Are the lead plates thinner? Does the battery have more heat issues? Has this been brought up before? What are your thoughts?

Thanks

mike95490 · December 2016

Can you get the weight of each of the batteries you are considering. Sometimes extra capacity is larger (taller) plates in the same case size, or less sump space (for shed material) Stationary batteries don't shed as much as, say forklift batteries bouncing all over the shop floor.

706jim · December 2016

Extra capacity in the same size case lends me to think that the plates are thinner. I had two group 24 size Die Hard batteries fail in three seasons on my boat while the replacement lower rated batteries lasted over ten seasons. For this reason, I went with the lower capacity 370 Ah Trojan L16's.

Only time will tell if I made the right choice.

Estragon · December 2016

The 550 has 10lbs more lead which is about 10% more.

Acid strength can change capacity too but it looks like the extra lead to me. Might be worth asking Surrette if the plates are thicker or maybe taller. Taller makes more sense to me which may mean less space above (need to be more careful checking water) or maybe less space on the bottom for shedding. They both appear to be in the same sized case.

Estragon · December 2016

@706jim - depends what you use them for. The diehards were likely a starting battery designed for high current for short period. Thinner plates give more surface area for fast discharge and more cranking amps. Deep cycling them kills them. L16s are likely made for deep cycling but not great at high discharge rates. Ideally having separate house and starting batteries is the way to go.

Vic · December 2016

"S-480 verses S-550" has come up before, IIRC. OR, perhaps it was asking about the Comparison between Surrette S-550 verses S-600 ...

Believe that Estragon's read on things is pretty much correct.

When I last looked the comparison between two different model of Surrette L-16 batteries, the ratio of Ah Capacity verses dry weight, the ratio was very close.

On the Surrette Data Sheets, the stated Capacities were both for electrolyte SGs of 1.280. Have never seen any Surrette Solar batteries that had SGs other than 1.265. This reduction (which is a good thing) reduces the stated Capacities in the table on the Data Sheets, by 5%. And, as is well-known, for the S-line of batteries, the S- number is the 100-hour Capacity, not the more customary 20-hour rate, that we all use, here.

S-550 Data Sheet:
https://www.solar-electric.com/lib/wind-sun/S-550.pdf

S-480 Data Sheet:
https://www.solar-electric.com/lib/wind-sun/S-480.pdf

As you can see, there are two more plates for the S-550 (17, verses 15)
The S-550 weighs 94 Lbs Dry, and has 29 Lbs of electrolyte.

The S-480 weighs 81 Lbs and has 31 Lbs of electrolyte (fewer plates = more room for electrolyte).

Between these two battery models, they each have identical: Plate dimensions and thickness, identical separator and envelope thicknesses, identical electrolyte reserve (above the plates), and identical stated SG.

It IS certainly very good that Surrette seems to specify almost everything that almost anyone would want to know about the innards of their batteries, IMO.

So, bottom line, there is a bit less electrolyte volume in the S-550, and being a bit higher Capacity, the 550 will consume a bit more water, and have a bit less water to lose. So, checking water a bit more often on the 550s, would not be a bad idea.

In my experience, believe that the Surrette L-16 Flooded batteries have a greater electrolyte Reserve than the other L-16, that I've dealt with (we still are running a 12 V set of S-530s that are in their 12th year ...).

Will check the above once again to make sure that it is correct, as far as it went.
FWIW, Vic

boxphotographer · December 2016

Thank you all for the fast replies and great info.

Vic - thanks for the very detailed reply.

My take away is that the s-550 do not seem to be inferior from a reliability standpoint - as long as one checks the electrolyte levels regularly, which one should do anyways.

I think I will go with the S-550's, we could really use the additional Ah and we will be close to the max recommended charge rate (under ideal solar conditions and a low daytime draw). So the S-550's will likely be happier on the chargers too.

Thanks guys, I really appreciate it.

Rolls S-480 verses S-550

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