Prodigy Parasite?

[Red-Rover]

A couple of months ago I purchased another vehicle in order to save miles on my towing truck. The truck now sits for long periods without running (charging battery) and I am wondering about parasitic power loss. Does the Prodigy brake controller draw power when not in use?
I know a battery maintainer would keep the battery up but I can just visualize myself backing out of the storage shed with that thing still plugged in.

[MEXICOWANDERER]

MATH!

.050 amperes (per hour) fifty Milli-amps

24 Hours

1.2 amp hours


1 week

8.2 amp hours


1 month

33.6 amp hours

A car battery that has been depleted of 33.6 amp hours

Will still start a car. The owner will never know.

But that battery if left unattended month after month except for starting the car once a month...

Has been cycled HEAVILY. Not the amp hours. Time spent discharged.

Disconnect a battery and the ECU computer loses it's mind until it has been toilet-trained again. There are no free-lunches anymore.

This is where a voltage measurement can be a bit more than purely useless. Purchase a solar panel just large enough to keep the battery maintained. DOUBLE the milliamp output for no workee at night time. Then regulate it to 14 volts max.

But you will have to disconnect a battery lead, the positive, touch the conductor to the engine block to discharge spurious capacitance in 10,000,000 little gizmos, then connect an ammeter set to milliamp scale inline with the positive cable and wait for current to stabilize.

That milliamp figure is your battery bleed down.


An exercise in futility - no one's going to do this 😞

[opnspaces]

Yes the Prodigy goes into a low power sleep mode. I made my own "remove before flight" type of flag for my TV. I took a piece of cardboard and cut it about steering wheel size and wrote "battery on charger" on it in magic marker. Then I used a razor knife to cut a hole about three inches from the top and a slit out to one of the edges.

Now when I plug the truck in I hang the sign on the steering wheel and close the door. I figure that if I manage to get in, move the sign out of the way to insert the ignition key, start the truck and back it away while still plugged in, I deserve to damage the cord.

When I'm driving I just slide the cardboard under the front seat to be used later.

[mkirsch]

Both Prodigies do go into a low-power "sleep" mode after a period of inactivity.

[MEXICOWANDERER]

Batteries love to be babied. There is a 2-pole connector with "Ford Type" bullets that are a simple push-in, pull out affair. Use an ADEL clamp which is a neoprene C-clamp for wiring to squeeze the ---- out of the wires right at the connector. Lube it up with silicone grease. Did this for several rural FD's and ambulances and it worked like a charm. They admitted later on they NEVER remembered to disconnect when they went on a run.

[DougE]

Anything your key fob can operate obviously must be drawing some power all the time.

[az350x]

Buy a "Remove Before Flight" flag and hang it on the steering wheel to remind yourself that it's plugged in. That's how we roll in aviation. 😉

[fj12ryder]

I've got the Prodigy 3 and it shuts down after a couple minutes of non-use.

My truck, 2001 Dodge diesel so 2 batteries, sat from last November to this May with no tender and no use. The Prodigy was plugged in, and the truck started fine when I went out in May to start it. It did turn over a bit slow, but not to the point I was worried about it not starting.

[Red-Rover]

Thanks for the replies. I didn't realize that door locks and radio drew power while the vehicle was inactive. Looks like a maintainer/charger is the best way to go with maybe a cardboard placard under the windshield wiper.
Thanks for the thoughtful replies!

[DougE]

To simplify, the Prodigy gets its control power from the 12v brake power feed which is always hot. You can always loop the extension cord for the battery maintainer over the driver's side mirror so you can't overlook it!

[j-d]

Likely hot all the time.

I've only worked this on a Ford, but controller was powered from a 30A fuse in the under hood box that was always HOT. I found this out the hard way. Replaced with a breaker. The RV shop said that if the vehicle has a dedicated fuse, they leave it in place and use it for the controller. If no fuse they used a breaker. Fuse/Breaker is sized for number of brakes it's powering. I think 30A for two axles/four brakes.
Anyhow, if I wanted that kind of amperage to run off the ignition switch, I think I'd want to add an HD relay and trigger it from the ignition ACC terminal.

[wa8yxm]

I believe that a properly installed Prodigy controller gets it's power from either the Accessory switched or ignition switched part of the fuse block and thus does not draw power when engine off.

Second. If you let it sit for months on end consider a "Battery Tender" (tm) type product.. They work well.

[j-d]

I remember a note in a Tekonsha manual saying the draw of a controller left connected (and I believe that was connected TO a trailer) was negligible. Different model, different time, but I think that if your battery is discharging, it is for some different reason than brake controller.

[Vulcan_Rider]

DownTheAvenue wrote:
The best strategy for the health of the battery and the vehicle mechanicals is to drive the vehicle every few weeks..

The best strategy probably is a combination of the two: Use a battery tender and "flag" it by leaving the hood open....or similar....AND actually run it for 20 minutes every 6 weeks or so and move it 6 inches to a foot to prevent a flat spot on the tires.

Also a periodic inspection of the engine compartment looking for rodent infestation is really important in some areas.

[mkirsch]

If there is any parasitic loss, it is very very tiny. No worse than anything else on the vehicle.

My advice to you is, get the battery maintainer and deal with the contrived "problem" of backing out of the garage with it still plugged in. You check the engine oil before you start it after sitting a while, right? If you don't trip over the cord doing that, you're doing something wrong. Tie a big yellow ribbon on it or something. Figure out a way to remember.

The benefits far outweigh the slight inconvenience of forgetting to unplug the charger one time. You'll only forget once and even if you forget the worst that will happen is you pull the plug out of the extension cord.