Common issue in the UK , this also does not help when the internal backup battery`s do not re-charge , the only soloution we found was to fit load balance equipment(UPS) and to carry spare power units as van stock , the UPS units did drop the amount being blown , but some customers are just not happy to pay after the initial investment , in that case all you can do is carry spare power supplies from de-installed kit and insist on UPS units being sold as a matter of default with all new systems.
APSS (SME)
ACSS (SME)
ACIS (UC)