Hi,

What is the price for new batteries if something goes wrong?

Why not something like that:
http://www.battery-chargers.com/catalog/25.pdf

USD 279.00
http://www.batterystuff.com/battery-...ti-volt-input/

Ask the manufacturer if it can be permanently installed on a vehicle.
From the picture it is not protected against rain. The charger must be
built to sustain vibrations.

* * *

DANGER! If the charger is permanently installed on the vehicle
there is danger of electrocution when you touch the vehicle.

* * *

DANGER! RISK OF BATTERY EXPLOSION FROM HYDROGEN GAS.
MAY RESULT IN BLINDNESS, SERIOUS INJURY, PERMANENT
DISFIGUREMENT AND SCARRING.


Best regards,

Luciano