What they are saying about boats is true for a trailer also aside from the starting part. But then they falls onto the tv. You have to use a deep cycle battery
for your trailer. We are buying 2 right now for our motorhome coach. If you have 2 you have to buy them in pairs. They need to be same date, same brand, same power, etc. If not they won't work as efficiently and will cause problems with the new one. One of ours has a dead cell but we can't complain. They are now 8 years old. They are from O'Reilly Parts and are Super Start brand. The last ones were about $80 with our discount which I have no idea how we get that but it is automatic. So far we've had good luck with their batteries.