Dead battery in toad

[Turfnsurf]

I am towing a 2019 Wrangler Unlimited Sport with a 2015 Itasca Sunstar 36y, both recent purchases. After towing the first time for only 50 min. the battery in the Wrangler was dead. Figured I did something wrong. Got the battery recharged and towed a couple of days later for 3 hours. Dead battery upon arrival at destination.
Wrangler has a Demco Stay in Play Duo, with a fused charging cable to the Jeep battery.
Checked the 7 pin on the coach. It's putting out 14.4 volts. Checked the continuity on the coiled cable that runs between the coach and toad. It's good.
I have seen on other posts that brake system draws 16-18 amps on start up and 10-12 amps while running. Is it just too much for the battery to handle? Is it too much for the recharging cable to handle?
No problems with the coach start up, so I don't think it's a battery problem with coach.
Sorry for the long post but wanted to explain everything I've already tried to solve the problem.
Anybody have any ideas?

[l1v3fr33ord1]

Turfnsurf-

First off, welcome to iRV2!

Second, you should add a "signature" to your profile. It contains whatever info you want; most people put info about their coach there, so they don't have to type it into each message. Instructions for adding a signature are here.

Re: Toad battery. It sounds as if the charging current from the coach is not reaching the Jeep battery. Possible causes include:

1) 12V charge line from Jeep connector not connected to battery positive terminal (correctly)
2) Ground from Jeep connector not connected to battery negative (correctly)
3) Ground from coach not common with ground on Jeep (as connected through the umbilical cable)
4) Excessive voltage drop from coach battery to Jeep battery (can be caused by small-gauge wire in umbilical or between connector and battery in Jeep)
5) Failed or missing fuse

I have the Duo in my toad, and the toad has a tiny battery. If the charge line could not keep up with the Duo, the battery would be dead frequently- and it's not. Thus, I don't think your problem is with the Duo.

[Ljwt330]

Originally Posted by l1v3fr33ord1

Turfnsurf-

First off, welcome to iRV2!

Second, you should add a "signature" to your profile. It contains whatever info you want; most people put info about their coach there, so they don't have to type it into each message. Instructions for adding a signature are here.

Re: Toad battery. It sounds as if the charging current from the coach is not reaching the Jeep battery. Possible causes:

1) 12V charge line from Jeep connector not connected to battery positive terminal (correctly)
2) Ground from Jeep connector not connected to battery negative (correctly)
3) Ground from coach not common with ground on Jeep (as connected through the umbilical cable)
4) Excessive voltage drop from coach battery to Jeep battery (can be caused by small-gauge wire in umbilical or between connector and battery in Jeep)
5) Failed or missing fuse

I have the Duo in my toad, and the toad has a tiny battery. If the charge line could not keep up with the Duo, the battery would be dead frequently- and it's not. Thus, I don't think your problem is with the Duo.

Agree with everything in this post^^.


One more thing to add. If the toad battery was dead after 50 minutes of driving, something besides lack of charge is going on, IMO, as that's too short of time to discharge the battery unless you had lots and lots of stop-and-go-driving and the Duo was set up correctly.


Do you have a way to know if the Duo is activating, while driving your coach? If not, you need to install an indicator of some type asap. If the Duo is not ON all the time, resulting in brakes being worn on the toad, then it's possible it is coming ON too often, say at the slightest slow down with the brakes or when the exhaust/engine brake is active.


Just something else to check out.

[groswald]

Before you pull your hair out, have your battery tested!

Jeeps don't come with great batteries. Mine was all of three years old when I started having the same problems. Had it checked - shot. Replaced it, and all is now good.

If that's not it then the previous advice is your best bet. If you have 14.4 volts at the battery end of the charge lead that should be fine. Check the amperage in the same spot if you can, too. Under load is best.

Good luck! Electrical problems are the worst.

Regards,

Randy

[Isaac-1]

One more thought, it may depend on which chargline kit was installed, some of them only put out 2-3 amps, such as this one https://www.rvupgradestore.com/Brake...-p/19-3252.htm.


Instead you want something like https://rvibrake.com/products/towed-...13115309260823


https://www.etrailer.com/Accessories...RM-156-25.html


or TOAD-CHARGE Dinghy Vehicle Battery Charger/Maintainer


depending on how much you want to spend and how fancy you want to get.


All of which can handle a 10 amp constant charge rate if the wiring along the way is up to the task