Description
The US AGM 31 is a 117Ah sealed 12V battery with a long, shallow case: 12.9 inches by 6.77 inches, 8.66 inches tall, 67 pounds. That weight is manageable for one person, which matters when the battery lives somewhere you have to reach into.
The useful comparison is with the US AGM 27 just below it. The 31 leads on the 20-hour rating (117Ah versus 108Ah), but the published discharge tests favor the smaller battery: at 75 amps the 31 gives 45 minutes against 55 for the 27, and at 25 amps it gives 207 minutes against 220. The 27 is also 6 pounds lighter. So the 31 is the pick for its 20-hour rating, its F12 terminal and its group 31 case, not for heavy-draw runtime.
Construction is the standard U.S. Battery AGM approach, with heat-sealed ABS, glass-mat electrolyte and no watering required.
Specifications
| Model | US AGM 31 |
| Voltage | 12V |
| Capacity @ 20hr | 117Ah |
| Capacity @ 5hr | 96Ah |
| Minutes of Discharge @ 75A | 45 |
| Minutes of Discharge @ 56A | 68 |
| Minutes of Discharge @ 25A | 207 |
| Length | 12.9in (328mm) |
| Width | 6.77in (172mm) |
| Height | 8.66in (220mm) |
| Weight | 67 lbs (30.5kg) |
| Terminal | F12 |
| BCI Group | 31 |
| Case Material | ABS, heat sealed |