Break away safety cord

A vandal removed my break away cord while the trailer was in storage. The two 110ah batteries went completely dead. Fortunately, magnets and wiring on the tandem axels survived which is a miracle. I contacted the manufacturer and they told me the magnets are not really designed to withstand the continuous power of two house batteries and would withstand power from a small 10amp hour battery. The 10AH battery would run down before damaging the 4 magnets drawing 15-16 amps. They gave me a procedure to check the magnets which I performed and it was a miracle that they check out ok. Also the on-road braking seems normal. The wiring in my trailer is 10 gauge with a long run to dissipate the heat and the connections were good enough to not produce the heat that would fry the wiring. The battery lives have been reduced because batteries do not like to be totally discharged.
I am now considering installing a 10AH battery set up for the break away system to prevent this from happening again.