Electrics: Ctek NXT 15 and RB4000, intelligent charger for all battery types and emergency start booster

The on-board electrical systems of modern boats have become significantly more complex. There are often several battery technologies on board at the same time: classic wet batteries as starter batteries as well as AGM, gel batteries or lithium iron phosphate systems for the power supply. As each of these technologies has its own requirements for the charging process, suitable charging methods are crucial. With the NXT 15 from Ctek, all battery types can be charged automatically and reliably.

Suitable for all battery systems

The NXT 15 is a 15-amp charger for 12-volt systems. According to the manufacturer, it supports all common battery technologies: Lead-acid (wet, AGM, gel, EFB) as well as lithium (LiFePO4).

According to the manufacturer, the charger automatically sets the appropriate voltage values for the different lead-acid battery variants. It also charges AGM batteries with the required, slightly higher charging voltage of around 14.7 volts to prevent the formation of lead sulphate crystals. A conventional wet-cell battery, on the other hand, would start to gas at such high voltages, which can shorten its service life. The NXT 15 is designed to recognise these different requirements independently and adjust the charging curve accordingly. With a charging capacity of 15 amps, the charger is suitable for larger battery banks of up to 350 ampere hours, according to the manufacturer. In our opinion, a value of 150 to 200 ampere hours is more realistic so that the batteries can be recharged overnight using shore power. The supply mode is helpful for winter storage, as it can supply the vehicle electrical system with 13.6 volts even when the batteries are not disconnected.

If the NXT 15 is to be used for lithium batteries, the device must be switched to this technology once. The charging process then also runs fully automatically. The NXT 15 costs around 250 euros.

Emergency power for motor and mobile phone

The RB 4000 is a portable starting aid, also known as a booster, with up to 1,300 amps of starting current. According to Ctek, it should enable up to 45 starts with one charge. The device is certified to IP65 - dustproof and protected against water jets. The RB 4000 also serves as a power bank for USB devices such as smartphones or Bluetooth speakers and delivers up to 30 watts of charging power. The booster's battery can be recharged via 230 volts or USB. With a recommended retail price of around 400 euros, the RB 4000 is one of the most expensive emergency start packs, but also offers plenty of power and extensive safety functions such as spark suppression and reverse polarity protection with a display.

TECHNICAL DATA

Ctek NXT 15:

Charger

• Charging power: 15 A
• Voltage: 12 V
• Supported battery types: Lead-acid (Wet, AGM, Gel, EFB), Lithium (LiFePO4)
• Modes: Fully automatic charging, trickle charging
• Special feature: Supply mode independent of the battery

Ctek RB 4000:

Start assistant/power bank:

• Starting current: 1,300 A
• Number of starts: Up to 45 (according to manufacturer)
• Protection class: IP65 (dust-tight, protected against water jets)
• Additional function: USB power bank, 30 watts, 88 Wh
• Work lamp

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