|Model – Code||TYST-120||TYST-240||TYST-360||TYST-480|
|Case||ABS Plastic case||ABS Plastic case||ABS Plastic case||ABS Plastic case|
|Nominal voltage||13,2 Volt||13,2 Volt||13,2 Volt||13,2 Volt|
|Capacity||2,5 A/h||5,0 A/h||7,5 A/h||10A/h|
|Max charge voltage||14,6 Volt||14,6 Volt||14,6 Volt||14,6 Volt|
|Min discharge volts||8 Volt||8 Volt||8 Volt||8 Volt|
|Max charge current||8A||16 A||24 A||32 A|
|Max Start current||150A||300A||450A||600A|
|Weight||590 gram||1000 gram||1300 gram||1900 gram|
|7 Ah||10 Ah||20 Ah||35 Ah|
|Self-discharge Rate||1.5% Per month||1.5% Per month||1.5% Per month||1.5% Per month|
|Typical motor cycle application||<125cc||125-250cc||500-1100cc||>1000cc|
|Typical aircraft eng application||Rotax 503||Rotax 583||Rotax 912, O-200||Jab 3300, O-320|
An aircraft voltage regulator which fails or is incorrectly set, and whose output exceeds 15,2V will permanently destroy a lithium starter battery. This over voltage will most likely destroy the avionics as well. If a lead battery had been installed, it will gas and dry out the plates, making it useless and probably irrecoverable and this will happen from about 14V upwards. LifePO4 batteries can safely accept 14,2V for many hours, so in fact will accept a higher bus voltage than a lead one. But a voltage runaway will destroy the battery, noticed by its melted case.
It therefore pays to fit some sort of overvoltage protection.
In the case of aircraft with alternators using separate regulators to control the field, a simple solution is to fit a “crowbar” over voltage protection device which trips the field circuit breaker when the voltage exceeds about 14,5V. These devices are obtainable from suppliers such as Aircraft Spruce, or you could even make your own.
In aircraft which do not have external field regulators, the over voltage protection device must disconnect the line between the regulator and battery when an over voltage event occurs.
Li-Start offers two types:
This unit disconnects the charging current when an over voltage is detected. It is most suitable for small engines such as Rotax, Jabiru, UL, etc
This is a sophisticated device which will disconnect the battery if over or under voltage is detected. This means you also protect the battery if you crank the starter until it stalls from a deep discharged battery, or if you leave the master relay on all week in the hangar.