
12V 300Ah Lithium Battery – Sports Series (Bluetooth W\Heater) (Model#12300-BTH)
Description
Spend less time worrying about power and more time doing what you came to do. The 12V 300Ah Sports Series (Heated) battery is built to deliver massive, dependable energy for high-demand marine, RV, and off-grid applications. Designed with over-engineered components, a rugged waterproof case, and a high-performance BMS, it provides consistent output without drop-off or failure. This isn’t a battery you manage—it’s one you rely on when everything else depends on it. Backed by a 10-year no-questions-asked warranty, it’s built to perform and built to last
Specs
Description
| Capacity 300AH |
Voltage 12V |
Weight 62.3 lbs |
Size 13.5” x 9.6” x 10.5″ |
Warranty 10 years |
Voltage: 12.8V
Capacity: 300Ah
Energy: 3840Wh
Efficiency: 98%
Memory Effect: None
BMS: Yes
Bluetooth: Yes
Weight: 62.3lbs
Dimensions: 13.5”x9.6”x10.5”
Built in Heater: Yes
Max Charge Voltage: 14.6
Max Continuous Charge/Discharge Current: 150A
Peak Discharge: 5S 400A
Low Cut-Off Voltage: 10V
Operating Temperature: -4°F – 140°F
Low Temp Charging Protection: Yes
Cell Type: Prismatic
Group Size: 50
Construction: Dual stainless steel air vents, pure brass terminals, custom waterproof case, integrated carry handle
Information
Built for Maximum Capacity. Built for Total Confidence.
Most high-capacity batteries sacrifice performance under load. This one doesn’t. The 300Ah Sports Series is engineered to deliver steady, reliable power across extended runtimes and demanding applications.
Not another underbuilt (Amazon) battery. Many options on the market are designed for light-duty use and fall short under real-world pressure. This battery is intentionally over-engineered for serious power demands.
Overbuilt Where It Matters:
– Advanced high-output BMS protection
– Custom waterproof case built for harsh environments
– Dual stainless steel breathable air vents to prevent condensation
– Pure brass terminals for maximum conductivity
– Integrated carry handles for easier installation
Engineered for Real Performance:
Whether you’re running long days on the water, powering off-grid systems, or demanding consistent output, this battery delivers without compromise.
Over-Engineered — Without the Overpriced Tag:
Backed by a true 10-Year No-Questions-Asked Warranty.
Specifications
| Manufacturer | Miller Technology |
| Model | 12V 300Ah Lithium Battery – Sports Series (Bluetooth W\Heater) (Model#12300-BTH) |
| Condition | New |
| Stock Number | 12300-BTH |
| Capacity | 300AH |
| Voltage | 12V |
| Weight | 62.3 lbs |
| Size | 13.5” x 9.6” x 10.5″ |
| Warranty | 10 years |
| Energy | 3840Wh |
| Efficiency | 98% |
| Memory Effect | None |
| BMS | Yes |
| Bluetooth | Yes |
| Dimensions | 13.5”x9.6”x10.5” |
| Built in Heater | Yes |
| Max Charge Voltage | 14.6 |
| Max Continuous Charge/Discharge Current | 150A |
| Peak Discharge | 5S 400A |
| Low Cut-Off Voltage | 10V |
| Operating Temperature | -4°F – 140°F |
| Low Temp Charging Protection | Yes |
| Cell Type | Prismatic |
| Group Size | 50 |
| Construction | Dual stainless steel air vents, pure brass terminals, custom waterproof case, integrated carry handle |







