My 2002 E150 Chateau has a second battery on the right-hand side just in front of the rear wheel, and I have a few questions that I hope someone might be able to help me with here.

1. What the heck is it for? Something to do with the trailer towing package perhaps?
2. How is it connected into the main battery? Presumably not directly in parallel ... I'd think that there would be a relay or something in between?
3. How the heck do you access it for maintenance or replacement?
4. Um ... anything else I should know about it?

Thanks in advance for any enlightenment that folks can throw my way.

 

I have an '03 E150 Chateau with the factory tow package and it doesn't have a battery in the location you describe. I have to say there is an area with enough room for a battery (probably not as big as the one under the hood but a 12 volt auto type battery) just ahead of the right rear wheel, in between a body mount and the shock mount cross member. Is this the area you are describing? The forward end of the leaf spring is near this area if that helps the description. Anyway, I still wouldn't have any idea about the battery except to say it may be a modification by a previous owner (unless you are the original owner).

 

Does it look factory or shade tree? Not familiar with that setup, but my guess it was for a trailer power source of some sort. There are wireing requirements for 2nd batteries that should be followed, if its not factory. You sure dont want a direct tie to the main battery with two #2's/4's/6's. Why dont you look on the towing forum a little further down----

 

like benshere sez: Does it look factory or shade tree?

i seem to remember the quigleys had the batteries under or near the side door entry steps. very possibly wrong, but maybe someone tried to duplicate that setup...

i am not able to speak with much experience on anything post 95, but on my 95 the second battery was installed on the passenger side in front of the heater box in the engine compartment and was smaller than the standard Group 24 or 27 battery fitted as the starting battery.
when i sourced the install parts they were under the heading "ambulance battery tray" or something like that. i did find that a group 24 will fit w/ some finessing. i also installed a pair of 6v golf cart batteries in the very rear right of my extended van. i used a couple of AFCO battery brackets and mounted the assembly to the frame, cut and fit an access panel into the floorboard (before i found the killer water fill system - bummer) to check and top off the batts.
perhaps going to one of the FTE FORD dealer parts website and searching under Ambulance package or some variation might help determine whether or not this was the factory method. for my year, all the ambulances i ever saw (worked for the radio and communications shop for San Diego City as an installer) were diesel and all had the second battery as well as the 300A alt and 300A fuse/fuseholder (that liked to melt from heat and oil and diesel mung). that's where i got the idea.

i no longer have a battery in the stock location - air filter from unique metal products lives there now - just the Gp24 in the ambulance location and the pair of deep cycle 6v's in back and a pair of 200A alt's to power them. two separate charging systems as the battery types do not like being tied together in any way on a single alt system.

neil

 

I have a 2001 E250 starcraft conversion with 6" lowered floor, raised roof and wheel chair lift. It has the 2nd battery that you describe. the tray pivots away from the frame to allow access for service. these vans can have alot of accessories that would overwhelm the electrical system, the 2nd battery helps to keep things working properly.

 

I have a 2001 E 150 Traveler, one of the options when I ordered it was the deep cycle 2nd battery to run all 5 power outlets and any media: The cigarete lighter, dash outlet, left side passenger outlet and the rear consol double outlets, ipod , play station and stuff that won't affect the starting battery. The charging system charges both at the same time but they have different power distribution. It's nice when the kids blast your radio all day and you can still start it to go home.

Happy trails

 

One key part that allows a 2nd battery to be charged by the vehicle alternator and only be tied in when the vehicle ignition key is on is called a "continuous duty solenoid". It looked just like the Ford start solenoid on the side panel except that it had a metalic case instead of the bakelite one which is OEM for the starter. It was used as a "school bus" part because they (and all heavy duty vehicles) had to have 2nd batteries.
The 2nd batteries I recall were mounted on the passengers side on top of the wheel well in a factory holder. The heavy duty solenoid was made by Cole-Hersee and just recently I saw one at a local marine store (Boats-B-us or West Marine). They are designed to stay pulled up for charging from the vehicle alternator the whole time the key is in the "on" position.

When the key is off, the solenoid will fall off and isolate the 2nd battery (provided you dont have any parallel circuitry to the vehicle battery----that would drain the vehicle battery if not isolated--not good)

 

<<<<< Originally Posted by slimdave View Post
My 2002 E150 Chateau has a second battery on the right-hand side just in front of the rear wheel, and I have a few questions that I hope someone might be able to help me with here.

1. What the heck is it for? Something to do with the trailer towing package perhaps?
2. How is it connected into the main battery? Presumably not directly in parallel ... I'd think that there would be a relay or something in between?
3. How the heck do you access it for maintenance or replacement?
4. Um ... anything else I should know about it?

Thanks in advance for any enlightenment that folks can throw my way.>>>>>

1. there are three levels of trailer connections for my '95. simplest is just 4 wires. most complex is 7 which uses relays for most functions and includes a 50A fused power source for the "trailer". _i_ cannot see any reason to have a second battery for the towed unit installed in the tow vehicle.
as answered by other folks, likely the second battery is there for a power source when parked so that no matter how drawn down it becomes, you still have the primary battery for starting the vehicle.
2. as mentioned previously, a constant duty solenoid was Ford's method of separating the second battery from the primary battery when the vehicle was not running. my personal problem with that is that rarely are the two batteries from the same production run, same size, in other words twins. paralleling two different batteries to charge from the same source is less than an optimum setup. if one must do this, i suggest ditching the CDS and installing a unit from http://www.hellroaring.com/ just my $0.02. also, if you must use a CDS, i like a 30 sec delay before actuating the CDS. we used to do this on the ambulances - gave the alt a moment to catch up before hit w/ a potentially high demand from a low second battery. CDSolenoids can be purchased for ~$25 btw. don't bend over at the boat guys. many good rebuilders can get them for you at a reasonable price. NAPA used to as well.
3. dunno. post some pix maybe??
4. i would most certainly track down the battery cable for the second battery to see where it leads so that i could test the voltage to determine whether or not the hidden battery was still viable. then i would try to determine how and where it is connected to the charging system. then i would get it out and check the water in it if it is not a maintenance free battery (which can generally be opened up and inspected anyway.)
what i am trying to say is it would be best to know if the battery was any good. if it is not, and it IS connected to the charging system, it will likely lead to premature failure of the alt or possibly even catastrophic failure of the battery - read BOOM.

just my thoughts
neil

 

I have a '96 E350 with factory tow package and an auxillary battery on the passenger side. It is stock and unmodified. I just had the pleasure of learning a lot (more than I wanted to know) about it. It is primarily intended for aux power for the trailer features. There is a 60A fuse (fuse T) in the Power Dist. Box (PDB) that protects the circut. Fuse T supplies power to fuses J & K, also in the PDB that protect the trailer running and backup lights circut and the trailer tow battery charge circut. There is a relay on the radiator support brace just above the headlight on the driver's side that energizes the circut to allow the aux battery to be charged from the alternator when the engine is running and to prevent the trailer features from discharging the vehicle's main battery when the vehicle is not running. There is a splice connection between fuse T and fuses J & K where the aux battery jumper comes in (presumably in the PDB as well).

In our case, we had a short in the trailer plug at the rear that grounded out the trailer tow battery charge terminal and melted down the plug. That put a lot of draw on the circut that drained the aux battery and shorted it out internally, which in turn put a huge strain on the alternator and fried it as well.

Once the short was found and fixed, fuse T kept blowing. We determined that the alt was bad and replaced it, but still fuse T blew. We thought that we had another short to ground somewhere in the wiring and or that the relay was bad. We traced and isolated the wiring with no change. We replaced the relay with no change. FINALLY we disconnected the aux battery and everything was fine. The aux battery was dead, and when we tried putting a charger on it, it started smoking...

A new aux battery is on order now. It is a C50 XHD from Interstate. Not too many battery manufacturers make a C50 size and it is not stocked locally in our area. So, we've been waiting for the past week for a new battery, hopefully that is the end of our problems.

Check out the thread "short in trailer wiring" under hotairjunkie (I think it is in the electrical forum) for more details and wiring diagrams of the circut, though your's might be a bit different being a much newer year model.

 

great post!

neil

 

Thanks. I just posted the final on the thread in the electrical forum. I was wrong, the thread is titled "what does this fuse do". The new battery was installed this evening, and everything seems to be working as it should, with no excess draw on the alternator, and all of the trailer features working properly. Lesson learned, check the basics before you jump into the complex...it also helps to have the wiring diagrams!

 

Ford Supplies a wiring kit and Pigtail kit to install aux batteries. Up to 2 under the passenger side frame rails. You have several uses for it. One was for Trailer Brakes, House Battery for Conversion vans. One for Charging a Bumper Pull or 5th Wheel battery.

Ford installed the wiring connections on all Econoline models. As they were used for Ambulances and Conversion Van RV's...You will need to wiring harness for the batteries which is $350.00 from Ford. You need the Pigtail Kit $50.00. Then you need the Diagram for all the types of wiring you might use. Mine is like 4'x4' fold out picture. Showing the location of all the connections needed to make.. And be advised you need the Relay and fuse box first. Which is next to the Coolant Recovery tank. It has a Gray connector blank over it. If it's not installed yet and a relay under the battery box...

If you hit a salvage yard. Take it all. You will need every part to make it work right.