Comparing Surrette/Rolls S-550 vs Trojan L16RE-B batteries for 48V off grid system

Re: Comparing Surrette/Rolls S-550 vs Trojan L16RE-B batteries for 48V off grid system

Hi jberg..,

Welcome to the Forum.

The Surrette S550 has been in production for a year or so, so there may not be that many here that have run them. I do have a bank of s-530s (the S-550 replaced the 530) that have been in service for 9.5 years, and have held up well, but they are nearing the end of their service life.

AH Capacity is not the only thing to look for in a battery, and it is good that you are asking for the experiences of others using these two candidate batteries.

The Surrette weighs about 5 lbs more than does the Trojan, FWIW.

The actual Capacity of the S550 is really 5% less than specified, as each of the C ratings in their table assumes the electrolyte is 1.280, which it is not. These batteries have a target SG of 1.265, which means that the nominal Capacity of the 550 is about 405 Ah.

For daily cyclic use in a Renewable Energy charged system, lower SG electrolyte is better, IMO. The Trojans are now running 1.277-ish SG electrolyte. This means that the Absorption voltage will need to be a bit higher than if these batteries also had the 1.265 SG of the Surrettes, in general.

I have had very good luck with the three Surrette banks in use here, and a neighbor also runs Surrettes, and has had very good luck with them -- about 9.5 years on all of them (knock on wood).

FWIW, Good Luck, Vic

Re: Comparing Surrette/Rolls S-550 vs Trojan L16RE-B batteries for 48V off grid system

Hi Jberg..,

These batteries have been fairly well tended, but last year, was very distracted building a shop, so they were a bit neglected then. They take a bit longer to EQ, now, and the self-discharge rate on the S-530 is a bit higher than when new. But they still truck along.

L-16 batteries may well be considered as a 5 - 6 year battery, if they are looked after well. Running more than one string of any battery requires more careful monitoring of string balance, and perhaps rotating batteries from one string to others to try to maintain balance.

Over a long period of time, balance does diverge on any Lead Acid battery. Because you are planning on running two parallel strings, you will want to get a Clamp on DC Ammeter (or use shunts, etc) to monitor the string current balance. And of course, use your Hydrometer to measure the SGs and the SG balance monthly or so.

More later ... opinions vary to a large degree on what is the best battery ... some of this is just luck, and much of battery performance over the long term, depends on how well they are tended, and how well the maintainer responds to changes made, based on monitoring of the bank, and so on.

FWIW, Vic

Have been running three separate banks of Surrette batteries.  Two independent banks are 48 V 4KS25s,  and one other bank is Surrette S-530s.   All are still going strong,  each in their 11th year ...   knock,  knock.

Have been very happy with Surrette support  over the years.   Surrette would be my first choice for the next bank of batteries,  when needed ...   FWIW,    Vic