DIY Accubox 12V LiFePo4 50Ah for Bluedrive Power Fin

The standard cruising time in the canoe with Power Fin and the included 8.8 Ah battery pack is 1 hour at a cruising speed of 4 km/h. This can be increased fivefold by assembling the battery box below. A pre-assembled battery box for this purpose is impossible to find in Europe, which is why I started this self-assembly project using better components such as LiFePO4 cells, BMS controller, switches, etc., with a DIY manufacturing cost of approx. €300 incl. VAT (excl. 10A LiFePO4 charger). 
The battery box for this purpose must be waterproof (IP67). In the future, I would like to be able to connect a 200W foldable monocrystalline Solar panel with a Victron SmartSolar MPPT 75/15 for charging.

       

* Bluedrive K Controller + Aqua Marina BT remote for Power Fin 

used by older models but controlling the same fin-motor.

The waterproof BT controller is mounted on top of box cover.
Remote Speed : High 6 km/h / Low 4 km/h / Reverse -1.8 km/h
Output to motor: Weipu bajonet connector WY20 4-pin

12V-240W-20A incl. kill switch, IP67
weight: 0,6 kg
price Alibaba: €86 +18

* Accu: LiFePo4 50Ah prismatic cells, 4p in series

Grade A;  3,2V

weight: 4,7 kg

L*W*H :148*115*39 mm per cell

price Ali: €77 incl. bus bars

 

* BMS: Daly Smart BMS 4S 12V 60A

TH-series incl. 3" LCD

active balancer 1A

incl. BT, UART, RS485, CAN, WiFi

safety features: short circuit, temp, current, voltage
Size: 125x66x16 mm 
Weight: 0,18 kg

price Ali: €55 

including 3 inch LCD

 

* PP Waterproof Flight Case incl. hinged cover

Pressure valve and PU foam inside

Outside LxWxH : 27x25x18 cm

Inside    LxWxH : 24x19x13 cm

Total weight excl. charger: 7 kg

Price VidaXL : €31+5

* LiFePO4 charger

LiTime 14,6V - 10A
Lightweight Aluminium housing incl. fan
Intelligent 3-pfase modes: Preloading / CC / CV

Safety devices: Temp, Polarity, Short circuit, Overstain
Full load time 50Ah battery box -> 5 hour

Output: Anderson SB50 connector

Size: 180*91*52 mm

Weight: 0,94 kg

Price Amazon: €70

 

AWG table

* Cabling: AWG10 / 6mm2 flex cabling

fused 30A autom.

* Output: USB-A (18W) / USB-C (30W) 12V USB-charger,

waterproof aluminium plug mounted in front of accu box, €17

* Input: Anderson connector to 10A LiFePO4-charger 

mounted inside the battery box

Wiring diagram