Complete repair guide for the Pleasure-Way Ascent – 12V Lithium Battery Bank & Solar Upgrade. Follow these steps to diagnose and fix the issue yourself.
Parts & Tools You’ll Need
- 100Ah LiFePO4 drop-in lithium battery
- Victron SmartSolar MPPT charge controller
- Victron BMV-712 battery monitor
- 40A DC-DC battery-to-battery charger
- 200W flexible solar panel
- ANL fuse holder + 200A fuse
- 4/0 AWG welding cable (battery interconnect)
- Bus bar / power distribution terminal block
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Step-by-Step Repair Guide
Step 1: Diagnose Existing Power System
Begin by disconnecting your existing lead-acid battery and documenting your current electrical configuration, including wire gauges, fuse locations, and load requirements. Test your solar panel output and existing charge controller settings to establish a baseline for your upgrade, ensuring you understand how much power your Ascent currently generates and consumes.
Step 2: Disconnect Battery and Install Fusing
Remove your existing battery completely and install the ANL fuse holder with the 200A fuse as close as possible to your battery bank location, typically within 18 inches of the positive terminal. This critical safety step protects your entire electrical system from short circuits and arc faults during the installation process.
Step 3: Run Primary Battery Interconnect Cable
Route the 4/0 AWG welding cable from your fused positive terminal through a dedicated conduit to your main power distribution bus bar, keeping the cable away from heat sources and sharp edges. Install appropriate inline fusing at both the battery and bus bar ends, following the cable manufacturer’s specifications for maximum safe current ratings.
Step 4: Mount LiFePO4 Battery in Secure Location
Install the 100Ah LiFePO4 battery in your designated storage location using vibration-damping straps, ensuring it cannot shift during vehicle movement. Position the battery so the built-in battery management system (BMS) has adequate ventilation and you have easy access to terminals for cable connections.
Step 5: Install Victron Monitor and Charge Controller
Mount the BMV-712 battery monitor on your dashboard or interior wall where you can easily read it, connecting its sense leads directly across your battery terminals for accurate state-of-charge readings. Install the SmartSolar MPPT controller in a well-ventilated location near your battery bank, following Victron’s wiring diagram to connect solar input, battery, and load terminals with appropriately sized conductors.
Step 6: Connect Solar Panel and DC-DC Charger
Mount your 200W flexible solar panel on your van roof using adhesive backing or mechanical fasteners, then run the panel leads to your SmartSolar controller with proper inline breakers and disconnects. Wire your 40A DC-DC battery-to-battery charger between your engine battery and lithium bank so it can charge the LiFePO4 while you’re driving.
Step 7: Test Complete System Integration
Connect your battery, monitor solar generation and charge rates through the Victron app, and verify that your BMV-712 displays accurate state-of-charge and voltage readings. Load-test the system by running your typical RV appliances while monitoring the discharge rate, then check that your DC-DC charger activates when the engine starts and properly charges your lithium battery.
Recommended Parts
| Part | Link |
|---|---|
| 100Ah LiFePO4 drop-in lithium battery | View on Amazon |
| Victron SmartSolar MPPT charge controller | View on Amazon |
| Victron BMV-712 battery monitor | View on Amazon |
| 40A DC-DC battery-to-battery charger | View on Amazon |
| 200W flexible solar panel | View on Amazon |
| ANL fuse holder + 200A fuse | View on Amazon |
| 4/0 AWG welding cable (battery interconnect) | View on Amazon |
| Bus bar / power distribution terminal block | View on Amazon |