What to charge the propulsion batteries directly at the airport is a common question of RC modellers. The first thing that comes to everyone's mind is that the battery in the car will do. But this solution has its pitfalls. It is not a question of if, but when, the vehicle will also fail to drive away after charging the RC model's powertrain for a day. Next in the line of ideas is to use an external lead-acid battery and when it runs out we "just" end the flight day.
An external LiFePO4 battery is a better choice:
It is lighter (Optima YELLOW TOP 38Ah weighs 12.5 kg and ELERIX LiFePO4 12V 30Ah weighs only 3.2 kg)
It has a longer service life than PB, up to 2000 cycles and a life of 10 years.
Higher stored capacity (PB 50% and LiFePO up to 85% - that means BP Optima 38Ah will deliver 19Ah and from LiFePO 30 Ah we will use 25.5 Ah :-)
Require less maintenance than lead-acid batteries because they do not need to be recharged as often (they do not self-discharge)
No memory effect - this means you can charge and discharge the battery at any time without affecting its lifetime
Excludes no toxic chemicals
No risk spontaneous combustion, fire and explosion
Yes, the dimensions of 135 x 167 x 80 mm, the weight of 3.2 kg and the capacity of 30 Ah are very pleasing. It is a compact and lightweight power supply that is easily portable.
We recommend an operating voltage of 3.1 to 3.4 volts for LiFePO4. Anything else unnecessarily reduces battery life!
The A123 battery is a high performance battery with a long life and weight to volume ratio.
LiFePO4 batteries are also very safe. They have no tendency to spontaneous combustion or explosion and are therefore also suitable for propulsion, but more on that next time...