Charging house and chassis batteries / How often to disconnect from shore power

[Charging house and chassis batteries / How often to disconnect from shore power]

I have 2003 Fleetwood Flair 31A and have been hooked up for months at a time.  But I do take mine out every 4 to 6 weeks for maintenance runs of 45minutes.   My batteries are Interstate and over 5 years old (flooded)   I do check my batteries every month and only use distilled water.   I also use a hydrometer about ever 6 months.  So like others I believe converter is overcharging your batteries

[How Often to replace Surge Protector]

Hello

I purchased a Progressive EMS-PT30 about 5 Season ago.   It is working fine, my question is how often should as Surge Protector be replaced.  I'm sure there has to be a time frame when the effectiveness of an older unit will be of questionable use.   Anyone know of a way to test one of these units without sending it back to manufacturer.  

Thanks