The Essentials in 30 Seconds
- Professional Rule: shore charger at 30% of gross lithium bank capacity. 200 Ah bank = 60 A minimum charger. 400 Ah bank = 120 A charger.
- LFP profile imperative. Never lead-acid profile (destructive overvoltage). All Victron Blue Smart, Skylla-i, MultiPlus chargers have LFP profile as standard 2026.
- Brands distributed: Victron Blue Smart IP65 12V 25A (~ €350 ex VAT), 24V 13A (~ €215 ex VAT), Skylla-i 24V 100A (~ €1,200), Mastervolt ChargeMaster.
- MultiPlus inverter combo: 120-200 A charger + 3,000 W inverter in a single unit. Skysat standard for compact sailboat 40+ ft refits.
- 230 V shore power: 60 A charger at 12 V = 800 W AC side = 3.5 A at 230 V. Always below the 16 A marina standard.
The shore charger is the forgotten component of a lithium refit. Once the battery bank is replaced, the old lead-acid shore charger is often kept — slowly destroying the new cells due to an unsuitable charging profile. This article explains the correct sizing and the brands distributed by Skysat.
For the lithium bank it powers, see sizing your sailboat lithium bank.
Charger Sizing for Lithium Bank
Professional Rule: 30% gross bank capacity. i.e.:
- 100 Ah bank → 30 A minimum charger.
- 200 Ah bank → 60 A charger.
- 400 Ah bank → 120 A charger (MultiPlus combo preferred).
- 600+ Ah bank → 150-200 A charger (MultiPlus II).
Why 30%? A compromise between recharge speed (bank recharged in 3-4 hours to 80% DoD) and cell longevity (thermally acceptable rate, no stress). Exceeding this (50%) speeds up recharging but reduces lifespan.
LFP Profile — Why it's Mandatory
The charger applies a specific charging profile according to battery chemistry. For LiFePO4:
- Bulk: 14.4 V (12V bank) or 28.8 V (24V bank), maximum current.
- Absorption: 14.4 V for 30-60 min until fully charged.
- Float: 13.5-13.8 V (never continuous 14.4 V = cell stress).
A lead-acid profile (14.7 V absorption + 13.8 V permanent float) on lithium destroys cells within 6-12 months. All modern Victron chargers have a selectable LFP profile via VictronConnect.
Victron Blue Smart — Entry and Mid-Range
- Blue Smart IP65 12V 25A: ~ €350 ex VAT. For 80-120 Ah lithium bank.
- Blue Smart IP65 24V 13A: ~ €215 ex VAT. For 24V 50-100 Ah bank.
- Blue Smart IP67 12V 50A: ~ €480 ex VAT. For 150-200 Ah bank.
Smart = Bluetooth via VictronConnect for monitoring + LFP profile configuration. IP65/67 = acceptable water resistance in a damp locker.
Victron MultiPlus — Inverter Combo
The MultiPlus combines a 50-200 A shore charger + 800-5,000 W DC/AC inverter in a single enclosure. Automatic shore ↔ battery transfer in less than 20 ms.
- MultiPlus 12/3000-120: 120 A charger + 3,000 W inverter. ~ €1,850 ex VAT.
- MultiPlus II 12/3000-120: new version, integrated monitoring. ~ €1,950 ex VAT.
- MultiPlus II 24/5000-120: 120 A 24V + 5,000 W inverter. ~ €2,800 ex VAT. Yacht 45+ feet.
Advantage: space saving in the technical locker (1 enclosure instead of 2), intelligent shore power management (limits input current if marina breaker is exceeded).
Skylla-i and Mastervolt ChargeMaster — High-End
- Victron Skylla-i 24V/100A: ~ €1,200 ex VAT. Professional marine charger, IP21.
- Mastervolt ChargeMaster Plus 12/35-3: ~ €580 ex VAT. 3 independent outputs (house/start/3rd bank).
- Mastervolt ChargeMaster Plus 12/50-3: ~ €750 ex VAT.
- Mastervolt ChargeMaster Plus 24/20-3: ~ €680 ex VAT for 24V yacht.
Comparison Table of 2026 Models
| Model | Voltage | Current | Outputs | Price ex VAT |
|---|---|---|---|---|
| Blue Smart IP65 12V 25A | 12V | 25 A | 1 | ~ 350 € |
| Blue Smart IP65 24V 13A | 24V | 13 A | 1 | ~ 215 € |
| Blue Smart IP67 12V 50A | 12V | 50 A | 1 | ~ 480 € |
| MultiPlus 12/3000-120 | 12V | 120 A + 3 kW inverter | 2 | ~ 1 850 € |
| Mastervolt ChargeMaster Plus 12/35-3 | 12V | 35 A | 3 outputs | ~ 580 € |
| Mastervolt ChargeMaster Plus 12/50-3 | 12V | 50 A | 3 outputs | ~ 750 € |
| Skylla-i 24V/100A | 24V | 100 A | 1 | ~ 1 200 € |
Installation and 230 V Wiring
Workshop Rules — Shore Charger Wiring
- 230 V 3-wire cable (phase + neutral + earth): 1.5 mm² up to 16 A, 2.5 mm² beyond.
- 30 mA RCD (Residual Current Device) between shore power inlet and charger (ISO 13297 standard).
- Earth bonding connection: mandatory between charger casing and boat ground.
- DC cable sized to max current + 30%: Blue Smart 50 A → 10 mm² minimum cable.
- Class T fuse at charger output: rated 1.5× nominal current.
- LFP profile programming via VictronConnect before commissioning.
FAQ — Shore Charger in Practice
Can my old lead-acid charger charge lithium?
No, never. A lead-acid profile (14.7 V absorption + 13.8 V permanent float) destroys lithium cells within 6-12 months. Replacement is mandatory for lithium conversion.
Charger too powerful for my bank?
Not dangerous but unnecessary. A 100 A charger on a 100 Ah bank charges in 1 hour instead of 3 hours, but causes thermal stress to cells + unabsorbed current (BMS limit). No economic or technical advantage. Stick to the 30% capacity rule.
How many hours to recharge a 200 Ah bank?
With a 60 A charger: ~3 hours Bulk + 1 hour Absorption = 4 hours to go from 20% to 100% SOC. One night at the harbor is more than enough.
Are multi-battery outputs essential?
Useful if you have multiple banks (house + start + 3rd bank). The Mastervolt ChargeMaster Plus with 3 outputs intelligently charges each bank according to its needs. Otherwise, a 1-output charger + Argofet (charge separator) at €80-120 ex VAT.
What shore power capacity is available?
Standard marina France/Europe: 16 A single-phase = 3,680 W max. Côte d'Azur some premium harbors: 32 A = 7,360 W. Always under the marina's breaker (and the boat's).
Skysat distributes Victron Energy and Mastervolt. Indicative ex VAT prices 2026 from authorized distributor.
