Invisibrake did NOT charge tow battery

[mfish4299]

We drive a Thor ACE 30.1 towing a 2014 Honda CRV. We have the Invisibrake system and until this week, it has worked perfectly. On our current trip, we did 2 legs without unhooking our tow. The legs were short, less than 4 hours of driving each. After the second leg, we unhooked the tow and it would not start. Battery was dead, showing 4 volts on the voltmeter. Jumping the battery worked and the car started right away.

Question is, help me figure why the tow battery did not trickle charge from the invisibrake. It has always worked before and as far as I can tell, everything was the same. Thanks!

 

[Alfa38User]

Have you verified that the Invisibrake was actually working during your two short trips?? Simply thinking here that perhaps the fuse was blown and the system may not have been working as you expected!!!

 

[John From Detroit]

First question: Were those short legs all DAYLIGHT driving
Second: Did you drive with "Lights on for safety" or since it was daylight did you turn your lights (Head/Tail) off?

If the answer to the 2nd qustion is OFF,, Re-read the Invisible breake owner's manual..

 

[Mavarick]

Any time you find a dead battery it is a good practice to pay attention when you hook up jumper cables. Once the cable are hooked up and the dead battery is charging, before you try and start anything, look around to see what you left on in the car. Things such as heater or auto temp system, radio, navigation, etc all can pull more amps than some chargers can keep up with when combined with a brake. It might also mean you have a weak battery in the toad. I know yours is still new but for future info the original CRV battery is good for 3 yrs at best.
Then hook the system up again, start the MH and check voltage at the toad battery to see if the charger is actually charging the toad battery as it is supposed to. Good luck with it.

 

[Alfa38User]

Maverick

In this case, I think the Invisibrake itself is the 2A trickle charger in question. Thus the charge feature from the motor home may not be wired up.

For the Invisibrake charger to work, it seems that the parking lights on the motor home have to be on, at least that is what the manual says and this may be what John from Detroit is referring to: Pg2, Para 3. "Turn the motorhome park lights on ? this will activate the InvisiBrake charge circuit".....

But, what you have suggested is probably a better way even with the Invisibrake charging function operating, if the two would function ok together.

 

[mfish4299]

Thanks for all the suggestions. I know the motorhome lights were on during the second leg. Before the first leg, we actually did test the invisibrake to make sure it was functioning correctly. We tested both the brake function and all the connected lights. I did check the fuse from the battery to the invisibrake module and it was good. Nothing was left on in the car.

To test the trickle charge, do I need to disconnect the positive battery terminal on the toad and then test from the invisibrake wire to a negative ground?

 

[Alfa38User]

I would not think so. In order to charge a battery the voltage has to be higher than 12.5V or so. Set up your vehicle for towing (probably don't need to connect the tow bar though...), measure the voltage across the battery terminals, then turn on the parking lights of the coach in order to fire up the charger on the Invisibrake. Measure again, the voltage should now read somewhat higher (maybe 13.5V or so).

This method of testing should work but as I have no way of knowing, please let us know the results.... along with the 'before and after' voltage readings.

Do not expect to be able to charge a badly discharged toad battery by using the Invisibrake trickle charger. According to the owners manual, it is just that, a 2 amp trickle charger. It is used to maintain an almost full charged battery by "stealing" current from the parking light circuit  to replace what the brake is normally using without killing the battery. This method simply avoids connecting a charge lead from the tow vehicle by using wires that are already in place.

 

[Robert Olson]

We had the same problem and we tow a 2012 CRV.  When prepping the car for towing you have to have the lights and ac turned off.  When you turn off the engine, you will see some things on the dash are still powered-up (nav screen, mpg readout, compass direction, etc).  This is what is draining your battery.  The trickle charge is not enough to compensate for the drain.  You need to pull the fuse that protects those items (I looked but couldn't tell what # fuse it was).  I have a handy son-in-law and he installed a toggle switch under the dash and next to the steering column.  After I run through the transmission warm-up and shut off the engine, I flip the switch and everything on the dash goes black.  Camping World installed the Invisibrake and never told me about the fuse pulling.  Anyway, we have not had a dead battery since the fuse cutoff was installed.  Hope this helps.

 

[rebelsun]

We had the same problem and we tow a 2012 CRV.  When prepping the car for towing you have to have the lights and ac turned off.  When you turn off the engine, you will see some things on the dash are still powered-up (nav screen, mpg readout, compass direction, etc).  This is what is draining your battery.  The trickle charge is not enough to compensate for the drain.  You need to pull the fuse that protects those items (I looked but couldn't tell what # fuse it was).  I have a handy son-in-law and he installed a toggle switch under the dash and next to the steering column.  After I run through the transmission warm-up and shut off the engine, I flip the switch and everything on the dash goes black.  Camping World installed the Invisibrake and never told me about the fuse pulling.  Anyway, we have not had a dead battery since the fuse cutoff was installed.  Hope this helps.

I usually tow my bike on a trailer, but here is a commercially marketed product I looked at a while ago to use if I towed my CRV.............

http://roadmasterinc.com/products/accessories/electrical/fusemaster.html


I'll also include a review of a competing product, the Roadmaster Fusemaster.............

http://roadmasterinc.com/pdf/fm_mm_aug_13.pdf

 

[Drivmsafe]

The CRV owners manual tells you to be sure that ALL electrical items are turned because the key needs to be in the accessory position. I installed one of RVi brakes under hood battery charger. It's a simple 2 wire installation (battery and the 12v wire on the 6 way plug). It charges your battery as you're driving down the road through the motor home).

 

[cochise49]

We had the same problem and we tow a 2012 CRV.  When prepping the car for towing you have to have the lights and ac turned off.  When you turn off the engine, you will see some things on the dash are still powered-up (nav screen, mpg readout, compass direction, etc).  This is what is draining your battery.  The trickle charge is not enough to compensate for the drain.  You need to pull the fuse that protects those items (I looked but couldn't tell what # fuse it was).  I have a handy son-in-law and he installed a toggle switch under the dash and next to the steering column.  After I run through the transmission warm-up and shut off the engine, I flip the switch and everything on the dash goes black.  Camping World installed the Invisibrake and never told me about the fuse pulling.  Anyway, we have not had a dead battery since the fuse cutoff was installed.  Hope this helps.

Exactly what we had to do for our 2013 CR/V.....The NAV system is power hungry. Couldn't last more than 5 or 6 hours. Had a FuseMaster installed. Couldn't lie on my back on the floor long enough to do it myself and tired of pulling and reinstalling the fuse. I had actually damaged the CR/V fuse block under the dash by not being able to see what I was doing each time. Metal prong receptacle for the #19 fuse would short out killing NAV and Audio. Honda replaced it as a warranty item to their credit.  Was worth the cost for the switch.