My three AC Delco series 30 RV/Marine batteries are now 8 years old. Load tested them in the spring and they are still very strong. They are true maintenance-free batteries. I've used AC/Delco for years in different RVs (and in vehicles) and have never had a single problem. No need to check water — they are entirely sealed. I keep the RV batteries on a battery minder each winter. Golf cart batteries are not an option due to their height. To each his own, but I'll continue buying AC/Delco. BTW, I found that comparable AGM batteries don't have as high amp hours.