Installing batteries on yachts is often a challenge. They must remain securely in place when the ship is moving. Ampstar solves this problem with a modular system: the batteries have integrated fastening points and can be stacked. This means that several smaller units can be combined to form a larger system that can be flexibly positioned in the available space.
Stacking system for flexible capacities
The Ampstar batteries are equipped with a mechanical stacking system. There are guides on the top and bottom that allow several batteries to be stacked on top of each other and fixed in place. The batteries fit snugly and should not slip even in rough seas. The stacking height is only limited by the available height in the battery shaft.
The advantage lies in the flexibility: instead of one large 300 ampere-hour battery, three 100 ampere-hour units can be stacked. This offers greater flexibility when installing in confined spaces. The system is also practical for subsequent expansions: another battery is simply placed on top of the existing stack and electrically connected in parallel.
The stack connection is purely mechanical and is only used for fixing. The electrical connection is made separately via cables. This also allows non-stacked batteries to be connected in parallel - for example, if the starter and supply batteries are mounted in different places in the boat. The click system works with all Ampstar models.
Sophisticated fastening concept
In addition to stackability, Ampstar offers a flexible assembly system. The batteries have fastening eyelets on the sides, which can be used to secure them with straps or lashing straps. This is the simplest method and is sufficient for many installation situations. Ampstar offers suitable mounting brackets as accessories. These allow the batteries to be attached to vertical surfaces, such as a bulkhead.
Integrated Bluetooth and BMS
Each battery has an integrated Bluetooth module for monitoring via smartphone app. The app displays the state of charge, voltage, current, temperature and number of charging cycles. In the case of stacked batteries, all units can be monitored simultaneously - the app distinguishes them by their serial number. This saves the installation of expensive battery monitors.
The battery management system protects against overcharging, deep discharging, overcurrent and overheating. It also balances the individual cells within each battery. With batteries connected in parallel, each BMS works independently - the systems do not communicate with each other. This is common with LiFePO4 technology and works reliably as long as all batteries are the same type and, if possible, the same age.
The maximum discharge currents vary depending on the capacity. The 100 ampere-hour model can withstand 100 amperes continuously and more for short periods. For larger consumers such as bow thrusters or heavy anchor winches, several batteries should be connected in parallel - the currents then add up. Two 100 ampere-hour batteries together can supply 200 amperes.
Capacities and service life
The manufacturer relies on high-quality cell compression. Lithium iron phosphate cells have the property that they expand and contract during charging and discharging. This can cause the cells to age more quickly mechanically. This is prevented by compressing the cells in the battery housing. Ampstar uses a combination of steel strips and aluminium die-cast plates to hold the prismatic cells in place. This is intended to increase the service life of the battery.
The Ampstar series currently comprises two models with 100 and 300 amp hours. The 12-volt batteries therefore offer a capacity of 1,280 and 3,840 watt hours. According to the manufacturer, the batteries offer particularly high discharge currents: The version with 100 ampere hours can be discharged with 150 amperes, the larger one with up to 200 amperes continuous load.
The German company from the Lower Rhine focuses on durability and safety. The housings are screwed together and can be opened for repairs. The Ampstar with 100 ampere hours costs 439 euros and the variant with 300 ampere hours 799 euros.
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Technical data:
Capacities:
- 100 Ah, 300 Ah
- Rated voltage: 12 V
- Parallel switchable
Mounting and assembly:
- Stacking system
- Integrated fastening eyelets
- Vertical or horizontal mounting
- Accessories: brackets, spacers, belt
Properties:
- Technology: LiFePO4
- Charging cycles: > 3,000
- Weight 100 Ah: 10.75 kg, 300 Ah: 27.10 kg
BMS functions:
- Overcharge protection
- Deep discharge protection
- Overcurrent protection
- Temperature monitoring
- Cell balancing
Monitoring:
- Integrated Bluetooth module
- Smartphone app
- Display: State of charge, voltage, current, temperature
Michael Rinck
Redakteur Test & Technik
