2016 Raindrop And A Dead Battery?

We are the Second owners of this 2016 Ultra-I went to plug in the cord to charge battery - but it won’t acceot a charge. I followed the troubleshooting in owners manual. The AC outlets work - the 12v and USB ports do not- nor do the lights. I took a multi meter to the 12v and it was dead. I then took the meter to my Jeep to make sure it was working and it read my Jeep battery was good. I took the panel off and exposed the battery- used the meter and it tested dead. It’s too heavy for me to lift out so I will have my husband Scott do so. Any thoughts of possibly jumping it from an external source or do I need to replace it? I read where some have had batteries for 10 years! I do confess to not having it plugged in all the time in my garage (lesson learned). I am a novice at all of this! This unit is filled with extra electronics as well- hoping that’s not going to cause battery issues in the long run. Any and all thoughts/suggestions are welcome.

This is the battery I have found for possible replacement ?
Amazon.com: NPP NP12-75Ah Rechargeable 12V 75 Ah Sealed Lead Acid Battery With Button Style Terminals: Home Audio & Theater

 

We just replaced ours at 11+ years after noticing it was only lasting about a day and a half between charges when I was at Oshkosh at the end of July, rather than the 3-5 days it normally lasted without being totally discharged, so I knew it was on it's last leg, but then it really didn't owe us anything anymore at this point.

FWIW, my understanding is that if a battery is allowed to totally discharge, especially more that once, that will greatly decrease it's life, if not end it.
Even the deep cycle type ones that are made to discharge more continuously and deeply than a starting type battery like in your car for instance, should not be totally discharged.
Ideally discharging down to about 15-20% of their full charge before being recharged would provide the longest life, but that isn't always easy to know. It's best to plug the trailer in when stored if possible as a matter of habit, so the automatic charger can keep it at an optimal charge without overcharging it, and to lessen the chance of it going dead due to something unintentionally being left on. My two cents worth anyway.

 

Thanks so much for the info. I will check the fuse for the charger as well, in case perhaps that is where the problems lie. although I see a green light indicator, I haven't checked that fuse. I also did not get the right 7 prong hook up on my jeep - I thought I had but come to find out he installed a 4 prong instead. Getting that installed, so that the camper can pull from the jeep when in tow, as well as always having it plugged in, I am hoping will help alleviate this issue in the future.

 

If you want the TV to charge the TD's battery while driving, and not just run the running, brake and turn lights, it will require a fairly heavy power and ground wire to the 7 pin plug as well, so it's more than just switching the wires from the 4 pin plug to the 7 pin one, since the 4 pin doesn't have that capability.
You should also isolate the TV from the TD, so that the TD dosen't drain the TV's battery and leave you stranded out in the boonies somewhere (and damage your TV battery to boot). That can be done either at the TD or the TV. If you do it at the TD it will be done for any TV you use. If you do it at the TV, it needs to be done for each TV used.

 

Update: As per Cary’s suggestion, I put the battery on a table charger overnight and viola - it’s charged completely. I lucked out. I will keep it plugged in now while in the garage to ensure the battery doesn’t get drained again!