Community Forums

NXR · 06-19-2020, 09:17 PM

In other words, what is the idle and maximum current draw of the Stay-n-Play DUO system?

I know it requires a 20-amp fuse but I'm trying to figure out the car battery charge line. I'm about to purchase it with the Coachlink wireless display so I can't just measure the amps, unfortunately.

I do not want to do the eTrailer thing and just run a wire directly from the motorhome 12 VDC circuit through a thermal breaker to the car 12 VDC system because it provides no isolation between the two. I'd rather go with the RVi Towed Battery Charger that actually provides isolation (although it might just be a very expensive diode) or something similar.

https://rvibrake.com/collections/fla...13115309260823

But the RVi system can only supply up to 10 amps. So if the Stay-n-Play DUO pulls close to 10 amps or more most of the time because the vacuum pump runs a lot, I can't use the RVi system, especially at night when the car tail lights are on.

So...I was wondering if any of you curious types ever put an ammeter on that thing to see just how hard it really is hitting the battery.

Thanks,

Ray

R.Wold · 06-19-2020, 10:24 PM

I think you are over thinking this. Just my humble opinion...

l1v3fr33ord1 · 06-20-2020, 04:43 AM

Ray-

I have not measured the current used by our toad's Stay-in-Play.

Our coach has a factory-installed 15A self-resetting circuit breaker on the coach end of the charge line. As it's a breaker, I would not know if the current exceeded 15A, or not.

I'd be surprised if a 10A charge line could not keep the toad battery charged with the "normal" usage profile of the Duo and other loads, such as the parking lights.

As mentioned in many other posts (and by your own), charge line components other than fuses/breakers (and in rare occasions, a diode) are optional. That said, if you want one that has a 15A rating, consider the LSL Toad Charge (lnk here). We have one on our toad; without it I would have had to install a diode in the charge line. (It is an expensive diode, certainly.)

NXR · 06-20-2020, 12:52 PM

Quote:

Originally Posted by l1v3fr33ord1

I'd be surprised if a 10A charge line could not keep the toad battery charged with the "normal" usage profile of the Duo and other loads, such as the parking lights.

As mentioned in many other posts (and by your own), charge line components other than fuses/breakers (and in rare occasions, a diode) are optional. That said, if you want one that has a 15A rating, consider the LSL Toad Charge (lnk here). We have one on our toad; without it I would have had to install a diode in the charge line. (It is an expensive diode, certainly.)

Thanks. That link is showing a 10-amp output?

We do drive with the headlights on and the incandescent parking lights should only be about an amp based on the wattage of the bulbs so that's about 10%.

The car has to be in the ACC position to unlock the steering wheel so the draw may be higher even with "accessories" shut off.

I was half-joking about the diode part, I hope. A diode will have a 0.6 volt drop across it so if it truly is a diode then you should see different voltages on each terminal. Have you ever noticed that?

R.Wold, maybe and hopefully. But I was asking myself how the heck that puny little pump could require a 20-amp fuse.

I imagine the pump cycles based on a pressure switch, or rather a negative pressure switch

, but maybe it runs constantly to assure there is always vacuum available. Or maybe it has a large starting draw; I just dunno.

I did send a query to Demco and if I receive a response I'll post it here.

Ray

EddieJ · 06-20-2020, 01:00 PM

The pump only runs when the unit is applying the brake.

l1v3fr33ord1 · 06-20-2020, 01:25 PM

Quote:

Originally Posted by NXR

Thanks. That link is showing a 10-amp output?

So sorry! I saw the 15A fuse rating for the LSL Toad Charge circuit breaker, and looked right past its "Powerful 10A Max. Output." So, same rating as the RVi unit.

We have not had a dead battery in 20,000 miles of towing through the "10A" Toad Charge- even with the puny battery in the Fit.

NXR · 06-20-2020, 06:53 PM

Quote:

Originally Posted by EddieJ

The pump only runs when the unit is applying the brake.

Perfect, thanks. Then the 10-amp RVi unit will be fine. eTrailer charges way too much for their line.

Ray

NXR · 06-20-2020, 06:53 PM

Quote:

Originally Posted by l1v3fr33ord1

So sorry! I saw the 15A fuse rating for the LSL Toad Charge circuit breaker, and looked right past its "Powerful 10A Max. Output." So, same rating as the RVi unit.

We have not had a dead battery in 20,000 miles of towing through the "10A" Toad Charge- even with the puny battery in the Fit.

No problem. Been there, done that.

Ray

DAJO · 06-21-2020, 06:14 AM

I used a earlier version of SMI brake system that had a vacuum pump. Never used any kind of charge line and never had a battery issue. Now use an AF1 no charge line on my 2012 Flex and now my 2020 Edge.

NXR · 06-22-2020, 03:29 PM

Demco responded rapidly: (edited a bit for readability)

Typical startup amp draw for the DUO is 16-18 amps & typical run amps are 10-12 amps.

The DUO only draws power when the braking system is actually running, so when it's receiving both the brake light signal from the coach & the G-Force Controller is feeling forward inertia.

The system won’t draw any power when just switching the system on, only when the 2 signals are present.

Ray