Upgrading to lithium is the single best improvement you can make to a motorhome electrical system. But it's not just swapping batteries - you need to upgrade your charging system too. This guide covers what you need, what it costs, and why it's worth every penny.
We've upgraded hundreds of motorhomes from lead-acid to lithium. The owners always wish they'd done it sooner - the difference in usable power and convenience is dramatic.
Typical Upgrade Cost
Entry Level (200Ah): £1,200-1,600
Mid-Range (300Ah): £1,800-2,400
Full System (400Ah+): £2,500-3,500
Includes batteries, DC-DC charger, solar controller (if needed), battery monitor, and professional installation
Why Upgrade to Lithium?
The benefits go way beyond just "more power" - lithium transforms how you use your motorhome:
Double Your Usable Capacity
200Ah lithium = 2400Wh usable vs 200Ah lead-acid = 1200Wh usable (50% depth limit)
→ Stay off-grid twice as long without any extra weight
50% Weight Saving
200Ah lithium weighs 25kg vs 200Ah lead-acid weighs 50-60kg
→ Reclaim 25-35kg payload for other gear or passengers
Fast Charging
Lithium accepts charge 3-5x faster than lead-acid
→ Fully charge in 2 hours vs 6-8 hours with lead-acid
10x Longer Lifespan
3000-5000 cycles vs 300-500 cycles for lead-acid
→ Lasts 10+ years instead of replacing batteries every 2-3 years
No Voltage Drop
Maintains 12.8V even at 20% capacity - lead-acid drops to 11.8V at 50%
→ Inverters, fridges, and electronics work properly until battery is actually empty
No Maintenance
Sealed, no water top-ups, no sulfation, can be mounted in any position
→ Fit and forget - no checking water levels or equalizing charges
What You Need to Upgrade
A proper lithium upgrade isn't just new batteries - your charging equipment needs upgrading too. Here's what's typically required:
| Component | Necessary? | Typical Choice | Cost |
|---|---|---|---|
Lithium Batteries The core upgrade - replaces your old lead-acid with modern lithium | Essential | 200-400Ah LiFePO4 | £800-2000 |
DC-DC Charger Correct voltage profile for lithium - old split charge relays won't work properly | Essential | 30A (Victron Orion) | £150-250 |
MPPT Solar Controller Ensures solar charges lithium correctly at 14.4V bulk, 13.5V float | If you have solar | Victron SmartSolar | £100-200 |
Mains Charger Replaces old lead-acid charger with lithium-compatible one | If you use hookup | 30A Smart Charger | £150-300 |
Battery Monitor Shows accurate state of charge - voltage-based monitors don't work well with lithium | Highly Recommended | Victron SmartShunt | £100-150 |
Can't I Just Swap the Batteries?
Technically yes, but you'll damage the lithium batteries long-term. Old lead-acid chargers use wrong voltages (14.7V+ equalization), and split charge relays don't charge fast enough. You'll also have no accurate way to monitor state of charge. Do it properly the first time.
The Upgrade Process
Here's what happens during a professional lithium upgrade installation:
System Assessment
We measure your current consumption, check existing wiring and fusing, and calculate correct battery size for your usage. Most motorhomes need 200-300Ah lithium (equivalent to 400-600Ah lead-acid).
Remove Old Batteries
Out with the old heavy lead-acid batteries (we recycle them responsibly). Clean the battery compartment and check mounting straps.
Install New Lithium Batteries
Mount new lithium batteries (200-400Ah depending on your needs). Connect with correctly sized cables and appropriate fusing. Series/parallel wiring if using multiple batteries.
Upgrade Charging Equipment
Remove old split charge relay, install new DC-DC charger (30A Victron Orion). Replace old solar controller with MPPT. Replace mains charger if needed. All configured for lithium charging profile.
Install Battery Monitor
Fit Victron SmartShunt battery monitor so you can see accurate state of charge, current draw, and time remaining. Connect to Bluetooth app for monitoring from your phone.
Testing & Commissioning
Test all charging sources (engine, solar, mains). Verify correct voltages. Load test the system. Walk you through the battery monitor app and show you how to maximize battery lifespan.
Installation Time
Most upgrades take 4-6 hours depending on complexity. We can do it at your location (mobile service) or you can visit us. System is fully operational the same day.
Real Cost Example
Here's what a typical 200Ah lithium upgrade costs for a standard motorhome:
Is It Worth It?
Compare to replacing lead-acid batteries every 3 years at £400-600, plus the inconvenience of limited power and constant charging. Over 10 years:
- • Lead-acid: 3-4 replacement sets = £1,600-2,400
- • Lithium: One-time upgrade = £1,726 (lasts 10+ years)
- • Plus: Double the usable power, no maintenance, half the weight
Common Questions
Can I use my existing chargers and controllers?
Maybe. If they have lithium profiles (14.4V bulk, 13.5V float, no equalization) they'll work. But most pre-2018 equipment doesn't. We recommend upgrading for optimal performance and battery longevity.
Will it fit in my current battery compartment?
Usually yes with room to spare. A 230Ah lithium battery is similar size to a 110Ah lead-acid. You're replacing 2x 110Ah lead-acid (220Ah total) with 1x 230Ah lithium that gives you more usable power and weighs half as much.
What about winter camping? Can lithium charge in cold?
Modern lithium batteries like Fogstar Drift Pro have built-in heating systems - they heat themselves when charging below 0°C. You can discharge lithium down to -20°C with no issues. Far better than lead-acid in cold.
How long does lithium last compared to lead-acid?
Lithium: 3000-5000 cycles = 10+ years of regular use. Lead-acid: 300-500 cycles = 2-3 years. You'll need to replace lead-acid 3-5 times before lithium wears out. Lithium is dramatically cheaper long-term.
Professional Lithium Upgrade Service
We specialize in motorhome lithium upgrades - we've done hundreds and know every potential issue. We'll assess your current system, recommend the right capacity, and install everything properly with full testing. Your motorhome will have double the usable power and you'll wonder why you waited so long.
- Free system assessment and upgrade quote
- Premium batteries (Fogstar, Victron) with full warranty
- All charging equipment upgraded to lithium-compatible
- Battery monitoring with smartphone app
- Mobile service - we come to you
- Same-day installation and testing