I’m working on the boat’s electrical system, which is designed as two redundant setups.
Current Solar Equipment
6 × 200 W Renogy 24 V solar panels
Space for a 7th panel when needed
1 × 50 A Tracer MPPT
1 × 40 A Tracer MPPT
Existing Temporary Power Setup
Setup One – High-Load / Cooking
2 × 300 Ah Renogy 12 V LiFePO₄ batteries
Old 3000 W 12 V inverter
Powers: Travel kettle, Induction hob
2x Batteries: https://uk.renogy.com/products/core-mini-12-8v-300ah-lithium-iron-phosphate-battery?variant=51704535646526
Setup Two – House / Low-Power
1 × 100 Ah 24 V LiFePO₄ (no-name) with junction box with fuses
Loads:
2 × 45 W USB-C chargers
24 V → 12 V 20 A DC-DC converter for legacy gear
Mounted as a single unit on a plywood board
Physical Changes – Both systems need to be moved onto a new 18 mm wooden platform under the floor, to improve space usage and add ballast.
Planned Architecture – The goal is to split the system into:
24 V house system (lighting, pumps, USB, laptops, legacy gear)
48 V high-power system for induction cooking and a future 48 V electric 8 hp outboard motor
Moving to 48 V is necessary to get enough power for the outboard and reduce current, cable size, and wiring cost to improve overall efficiency.
Solar layout:
One side of the boat fits 4 panels → feeds the 48 V system
The other side fits 3 panels → feeds the 24 V house system
Upgrade Options for the 48 V Side
Option 1 – Build 48 V from Existing 12 V Batteries by buying 2 more 300 Ah Renogy 12 V batteries. Configure 4 × 12 V in series → 48 V, 300 Ah
Feed a new all-in-one 48 V inverter
Frees up the 40 A Tracer MPPT for the house bank
Pros
Uses the same battery model
IP65-rated (important below the waterline)
Very strong starting capacity: 300 Ah @ 48 V
Cons
More wiring, more space needed
Cost: ~£1,200
Option 2 – Server-Rack Battery for 48 V
Move the existing 2 × 300 Ah 12 V batteries to the 24 V house system
Remove the no-name 24 V battery
Buy a 48 V 100 Ah server-rack battery: https://uk.eco-worthy.com/products/eco-worthy-48v51-2v-100ah-server-rack-battery-with-bluetooth-wifi-5-12kwh-lithium-battery-version-3
Add more batteries later as needed (especially once the motor is installed)
Pros
Much simpler wiring, built-in breakers, BMS communication, monitoring and better space efficiency. They will also be easier to expand and likely better balanced long-term
Cons
Metal case, not waterproof
Will need a second unit fairly soon for the outboard
Cost
£1,000 initially
- ~£600 later for expansion
Bonus
House system ends up with 300 Ah @ 24 V instead of just 100 Ah
Pros and Cons by System
Cooking / Outboard (48 V Side)
12 V batteries in series (Option 1):
More wiring and space
IP65 rating is a big advantage, as batteries sit below the waterline and flooding is a real risk
Native 48 V batteries (Option 2):
Better packaging and cleaner install
Built-in safety and monitoring
Easier upgrades
Less water-resistant
House System (24 V Side)
Current setup works, but:
The no-name battery may not be reliable long-term
More capacity is always useful
Planned addition:
24 V diesel heater (backup to the wood burner)
Extra capacity will matter in:
Dark winters
Periods when the wood burner isn’t usable
Bottom Line
Once everything is costed properly, both options end up close in price.
The real trade-off is between:
Waterproof, modular 12 V batteries (robust, proven, messy wiring)
Clean, native 48 V systems (tidy, scalable, but less flood-tolerant)
The decision really comes down to flood risk vs long-term simplicity and expandability.
UPDATE: the problem with the metal cased batteries will be condensation, leading to rust and failing circuits.
#DRAFT
Boating Europe 