Rolls-Surrette S2-1275AGM deep-cycle 2V AGM battery, 1150Ah/20h capacity, 2 + 5 years warranty (minimum order qty.)
Rolls Surrette has built a solid reputation over the years as one of the best, if not THE best, sources of deep-cycle batteries. Their sealed AGM batteries feature a high cycle life without the need for maintenance. The AGM technology (Absorbed Glass Mat) keeps the electrolyte (acid) contained in the sponge-like glass mats allowing Surrette AGM batteries to not expel any liquids even under severe overcharge. AGM batteries are non-hazardous, resulting in lower shipping costs and they can also be shipped via air. AGM batteries have a very low self-discharge rate, and can handle higher charge currents vs. regular flooded lead-acid batteries.
The AGM line batteries are designed for a variety of maintenance free applications and come with a solid 7 year warranty. Sealed AGM batteries can be placed anywhere without having to worry about fumes. They are also somewhat more suitable for cold places as they are more frost-proof than regular flooded lead-acid batteries.
Adding batteries in series increases the Voltage, while keeping the Amp-hour size the same. Adding batteries in parallel keeps the Voltage the same, while increasing the Amp-hour size of the battery bank. For example, six S2-1180AGM batteries (1100 Ah each) in series makes for a 12 Volt / 1100 Ah battery bank. Adding another string of six S2-1180AGM batteries in parallel to these will increase the bank size to 12 Volt / 2200 Ah.
Recommended Charge Settings (at 25C)
|Charge State||12 Volt||24 Volt||48 Volt|
|Bulk||14.7 Volt||29.4 Volt||58.8 Volt|
|Absorb||14.7 Volt||29.4 Volt||58.8 Volt|
|Float||13.8 Volt||27.6 Volt||55.2 Volt|
|Temperature Compensation: -4mV/°C/cell|
Equalize: Do not equalize AGM batteries (or set the equalize Voltage equal to the absorb Voltage)
Absorb time: 0.42 x C / I, where C is the 20-hour battery bank capacity and I is the real-world charge current
For example, a 48 Volt bank of six S2-1180AGM batteries, 1100Ah battery bank, with 10,000 Watt in solar PV would have a realistic charge current of around 150 Amp in full sun. That makes for an absorb time of 0.42 x 1100 / 150 = 3.1 hours = 3 hours 5 minutes
End Amps: If instead of time the current is used to determine the end of the absorb cycle, usually called ‘End Amps’, set it to around 2% of C20 (ie. for a 1100 Ah battery bank that would be 22 Amp as the End Amps setting, when the current falls below this value the batteries are full)
Maximum charge current: 25% of 20-hour battery bank capacity recommended (ie. 0.25 x 1180 = 295A for an S2-1180AGM battery for example), never more than 35%
Low-Voltage cut-off: 11.1 / 22.2 / 44.3 Volt (corresponds to about 80% Depth-Of-Discharge)
- 2 Volt maintenance-free VRLA Absorbed Glass Matt battery
- 1150 Ah at 20 hours, 1175 Ah at 100 hours discharge rate
- M10 threaded terminals
- Reliable and dependable in an impact resistant plastic housing
- Rope and molded plastic handle!
- Seven (7) years warranty: the first 24 months are full replacement, the next 60 months are prorated
- Our manufacturer info page
- Rolls / Surrette Web site
- Rolls / Surrette AGM batteries overview (pdf)
- Rolls / Surrette battery brochure (pdf)
- Rolls / Surrette S2-1275AGM spec sheet (pdf)
- Rolls / Surrette battery care manual (pdf)
- Depth-of-Discharge vs. Voltage for Surrette batteries (pdf)
- Rolls / Surrette warranty document (pdf)