Epoch Batteries
Epoch Batteries 12V 300Ah LiFePO4 Cranking Deep Cycle Battery
Epoch Batteries 12V 300Ah LiFePO4 Cranking Deep Cycle Battery
- Regular price
- Price: $1,599.00
- Regular price
- List Price:
- Sale price
- Price: $1,599.00
- Unit price
- / per
Notify me when this product is available:
Couldn't load pickup availability
PRODUCT DESCRIPTION
- 🇺🇸Free ShippingContiguous 48 states
- 🛡️11-Year Battery WarrantyBacked by Epoch
- ⚓Cranking + Deep Cycle1,000A peak for starting
- 💧IP67 SealedDust-tight, brief immersion
- 🔥Self-HeatingCharges down to -20°C
- 📞Real Human SupportSizing & setup questions
One Group 8D battery that starts your outboard and runs your house loads. The Epoch 12V 300Ah Pro Series (DP12300H) is a dual-purpose LiFePO4 battery: 1,000A of peak current for engine starting plus 3.84kWh of deep-cycle energy for electronics, pumps and appliances. It fits a BCI Group 8D footprint at 81 lb, has an IP67 sealed case, warms itself before charging in the cold, and reports to your phone over Bluetooth. In many compatible boats it replaces separate starting and house batteries.
Epoch rates cranking by peak current and duration, not CCA: 1,000A for up to 5 seconds or 800A for up to 10 seconds (tested above 60% state of charge at 25°C).
🔧 Will It Fit & Work for You?
A BCI Group 8D footprint built for starting and house power. Popular uses include:
- Outboard & inboard engine starting
- Combined start + house banks
- Bay boats, sportfishing & sailboats
- Marine electronics, livewells & bilge pumps
- RV & motorhome house power
- Off-grid solar & Victron systems
- 24V–48V systems (in series)
- Your tray fits 19.7" L × 10.5" W × 9.75" H (500 × 267 × 248 mm, Group 8D), and the mount can handle 81 lb. Install it upright.
- Your engine maker's battery requirement is met by 1,000A peak for 5 seconds (800A for 10 seconds). Epoch doesn't publish a CCA rating, so check your engine manual. Epoch cites compatibility with Mercury 250 hp outboards and other leading brands.
- Your house loads stay within 300A continuous (150A recommended for daily use).
- Your charger has a LiFePO4 profile. If your alternator can't charge lithium directly, plan on a DC-to-DC charger or lithium-ready regulator.
- Your main fuse and battery switch are sized for engine cranking current as well as house loads.
Why Boaters Choose a Dual-Purpose Lithium
Starts and Powers in One
1,000A peak for 5 seconds handles engine starting, and 300Ah runs your house loads. Fewer batteries, less weight and simpler wiring in compatible systems.
About Half the Weight
At 81 lb, it's far lighter than a typical Group 8D lead-acid or AGM battery, which Epoch puts at roughly 130 to 160 lb.
IP67 Sealed Case
Dust-tight and protected against temporary immersion to 1 m for 30 minutes. Not for submersion, water jets or pressure washing.
Cold-Weather Charging
With a charger connected, internal heating warms the cells to 10°C (50°F) before charging begins. Charge range is -20°C to 55°C.
Bluetooth + CAN Link
The free Epoch Pro app shows charge, voltage and temperature, with over-the-air firmware updates. CAN Link ports network multiple batteries, and the Pro Series communications box adds Victron and NMEA 2000.
Smart BMS Protection
Overcharge, over-discharge, over-current, high/low temperature and short-circuit protection (cutoff at 1,200A within 500µs), plus passive cell balancing.
📦 What's in the Box
-
12V 300Ah Group 8D Dual-Purpose LiFePO4 Battery (DP12300H)Bluetooth, CAN Link ports & internal heater
Lithium vs. Lead-Acid Group 8D
| Epoch 12V 300Ah 8D | Typical Lead-Acid | |
|---|---|---|
| Weight | 81 lb | Roughly 130–160 lb |
| Starting + house in one | Yes, in compatible systems | Often separate batteries |
| Usable capacity | Most of the rated 300Ah | About half, to protect battery life |
| Cycle life | 6,000+ cycles | A few hundred |
| Cold-weather charging | Built-in heater | Slow & inefficient |
| Phone monitoring | Yes, Bluetooth | No |
| Warranty | 11-year limited | Usually 1–2 years |
🔌 Charging Made Simple
Recommended: 150A
Charge at up to 150A for one battery (300A max from all sources combined). A smaller charger works fine, it just takes longer.
No Lead-Acid Modes
Use a LiFePO4 profile: absorption 14.2V, float 13.8V or off. Turn off equalization and set temperature compensation to 0.
Cold-Weather Charging
In the cold, a connected charger powers the internal heater first. Once the cells reach 10°C (50°F), the battery switches to charging.
Charging From an Alternator?
Some alternators can't charge lithium directly. Epoch suggests a DC-to-DC charger, lithium-ready regulator or alternator protection device.
🛡️ 11-Year Limited Warranty
Pro Series terms. Register with Epoch within 90 days of purchase or keep your proof of purchase. Full terms at epochbatteries.com.
📋 Full Specifications
| Electrical | |
| Chemistry | LiFePO4 |
|---|---|
| Configuration | 4S3P |
| Nominal Voltage | 12.8V |
| Capacity / Energy | 300Ah / 3,840Wh |
| Operating Voltage | 10.0V – 15.4V |
| End of Discharge | 11.0V – 11.6V |
| Internal Resistance | <30mΩ |
| Continuous Discharge | 300A (150A recommended) |
| Continuous Charge | 300A (150A recommended) |
| Short-Circuit Protection | 1,200A cutoff within 500µs |
| Cycle Life | 6,000+ cycles (0.2C, 80% DoD, 25°C) |
| Self-Discharge | ≤3% per month |
| Series / Parallel | Up to 4 in series / up to 16 in parallel (4S4P max) |
| Cranking | |
| Peak Discharge | 1,000A (up to 5 sec) |
| Extended Peak | 800A (up to 10 sec) |
| Test Conditions | Above 60% state of charge, 25°C |
| CCA | Not rated by Epoch (rated by peak current and duration) |
| Physical | |
| BCI Group Size | Group 8D footprint |
| Dimensions (L × W × H) | 19.7" × 10.5" × 9.75" |
| Metric | 500 × 267 × 248 mm |
| Weight | 81 lb (about 36.7 kg) |
| Ingress Rating | IP67 (dust-tight, temporary immersion to 1 m for 30 min) |
| Terminals | M8 bolt, 8–10 Nm (71–89 in-lb) |
| Mounting | Upright only |
| Bluetooth | Yes, Epoch Pro app with OTA updates |
| Communications | CAN Link in/out; Victron & NMEA 2000 via Pro Series communications box |
| Temperature | |
| Charge | -20°C to 55°C (-4°F to 131°F) with internal heating |
| Discharge | -20°C to 60°C (-4°F to 140°F) |
| Storage (recommended) | 0°C to 35°C (32°F to 95°F) |
| Internal Heater | Yes, warms cells to 10°C (50°F) before charging |
| Charger Settings | |
| Bulk / Absorption | 14.2V (14.2V – 14.6V range) |
| Float | 13.8V (13.4V – 13.8V range), or off if your charger allows |
| Max Charge Voltage | 15.4V (limit, not a charger target) |
| Temp Compensation / Equalization | Off / Off |
| Certifications | |
| Product | UL 1973, CE, RoHS |
| Enclosure | IP67 (IEC 60529) |
| Transport | UN 38.3 |
| Ordering | |
| SKU | DP12300H |
| Series | Epoch Pro Series |
📄 Manuals & Downloads
📱 Get the free Epoch Pro app: App Store (also on Google Play, search "Epoch Pro").
❓ Common Questions
Can it really start my engine and run house loads?
What's the CCA rating?
Do I still need separate starting and house batteries?
Will it fit my Group 8D tray?
How much weight will I save?
Can I mount it in a wet bilge?
Can I check charge levels on the water?
Does it work with Victron or NMEA 2000?
Can I charge it from my outboard's alternator?
Can I wire several together?
Questions About Your Setup? Ask Us First.
Tell us about your boat, engine and electronics and we'll help you confirm cranking needs, sizing and charging before you buy.

LiFePO4 Chemistry
Lithium iron phosphate cells, one of the most stable lithium chemistries available
Built-In Smart BMS
Guards against overcharge, over-discharge, over-current, short circuit & temperature extremes
Zero Maintenance
No watering, no acid, no terminal cleaning
Backed by Epoch
Manufacturer warranty, plus real help from our team at 833-664-7433