Keeping Your Battery Charged While Using The Demco Stay-In-Play DUO Supplemental Braking System

Updated 12/19/2024 | Published 05/21/2021

Question:

I’m considering buying the demco stay in play. Can the battery of 2008 Jeep Wrangler still be disconnected as the manual indicates? Does the power come from the MH or must the jeep battery stay connected? Is so is there a trickle charge involved in the stay in play system?

asked by: Wendy

Expert Reply:

The Demco SBS Stay-IN-Play DUO Supplemental Braking System - Proportional # SM99251 is going to be connected to your vehicle's battery to be powered which will drain your vehicle's battery. To keep the battery charged while towing you can install the BrakeBuddy Towed Vehicle Battery Charge Kit Item # BB54FR. You'll still be able to disconnect the negative battery cable like the manual indicates for flat towing.

expert reply by: Kevin C

Jesse C.

12/19/2024

I recently had a Demco Duo Stay n Play installed in my 2021 Jeep Wrangler. When I went to pick it up at the installation site, The vehicle wouldn’t start, the battery had to be charged and was tested as good. Today 3-4 weeks later and with little use and storage in my garage. The vehicle again wouldn’t start and the electrical system behaved erratically and the Demco unit was clicking constantly until I disconnected my (-) battery clamp. I recharged the battery to fully charged and the vehicle started as it should. I’m waiting to hear back from the installation company Camping World, I have a long trip scheduled to start in two days. Any help to ensure I don’t continue to have an issue will be greatly appreciated.

Jameson C.

12/19/2024

@JesseC I would wait and see what a good solid charge does on the vehicle battery does. My assumption is that Camping World really killed the battery and the jump to get it going again wasn't enough to ensure the battery got a good charge. They could have had a door open on the Wrangler which had a dome light active for too long and killed the battery or something similar.

Jesse C.

12/19/2024

@JamesonC Just to clarify, after the first incident, I drove the vehicle over 400 miles then it sat in my garage for approximately 3-5 days. Our climate has been as low as 22 degrees at night. Then today the problem recurred. The battery recharged in about 3 hours. Does the Demco use energy when switched off and disconnected from the RV? Thanks for your prompt response.

Jameson C.

12/19/2024

@JesseC In that amount of time it should have charged unless the alternator is bad. If you have a multimeter see if there's a voltage difference on the battery when its running and when it's off. It should be almost a couple volts more when the engine is running. The Demco should not be using power when vehicle is off.