Battery and Battery Box

If it's a Marine battery they it should be OK and I agree that it doesn't sound like a deep cycle battery.

Something doesn't add up between your charger at 13.37V and the battery load test. But the best test is your own rig comparing it against past performance.

Switch the positive line on trailers. Connect the breakaway switch prior to the disconnect.

Drill holes in the box assuming it is on the tongue of the trailer.



12.37 is NOT a fully charged battery.

If it has a CCA rating, then it is not a true deep cycle battery.
Probably a dual purpose battery.

CCA ratings are for starting motors.

JohnG4706 wrote:

OK, took the battery out and brought it back to the house to start charging. Voltage read was 5.5V. Will keep my fingers crossed that I haven't ruined the battery.

CA Traveler responded:

Regardless of what happens during charging the battery life is compromised. After charging have the battery load tested to determine if it is/is not toast.

After 36 hours the "Green" solid light came on my Battery Tender Plus. Voltage was 12.37 VDC. I took it to Advance Auto Parts and they ran a test.

The battery is listed as 550 CCA and the test came back 535 CCA. The salesperson said this is "normal". Is this the compromise, loss of 15 CCA, that you refer to? IS this normal? I had the feeling the salesperson didn't understand deep cycle batteries.

Again, thanks.

phillyg wrote:

tll wrote:

I always install my battery switches on the positive cable. If installed on the negative, the brake safety switch won't activate in an emergency if you happen to have the battery switch turned off while towing.


I don't want to hijack this thread, but perhaps this will also help the OP. Correct me if I'm wrong, but if the battery is disconnected and regardless of which post is disconnected, there would be no voltage going to the brakes if the trailer disconnects from its hitch, correct?
His reply implies to me that the brake is wired to the battery post and not the load side of the switch. But yes the battery is needed for the brakes and any power from the TV only is probably inadequate.

Correct, positive lead of breakaway switch connected to battery all the time. Battery switch only on main trailer 12 V leads.

Drill holes for drainage.

phillyg wrote:

tll wrote:
I always install my battery switches on the positive cable. If installed on the negative, the brake safety switch won't activate in an emergency if you happen to have the battery switch turned off while towing.

I don't want to hijack this thread, but perhaps this will also help the OP. Correct me if I'm wrong, but if the battery is disconnected and regardless of which post is disconnected, there would be no voltage going to the brakes if the trailer disconnects from its hitch, correct?

His reply implies to me that the brake is wired to the battery post and not the load side of the switch. But yes the battery is needed for the brakes and any power from the TV only is probably inadequate.

tll wrote:
I always install my battery switches on the positive cable. If installed on the negative, the brake safety switch won't activate in an emergency if you happen to have the battery switch turned off while towing.

I don't want to hijack this thread, but perhaps this will also help the OP. Correct me if I'm wrong, but if the battery is disconnected and regardless of which post is disconnected, there would be no voltage going to the brakes if the trailer disconnects from its hitch, correct?

I always install my battery switches on the positive cable. If installed on the negative, the brake safety switch won't activate in an emergency if you happen to have the battery switch turned off while towing.

At 5.5V in all probability you are now in the market for a new battery.