Did not add after the fact but ordered from factory with Dual Medium Duty Batteries & Extra Extra Heavy-Duty Alternator. Wouldn't have it any other way. I have read of others have installed /upgraded to a dual setup.

Here is a generic video:

Here is a kit offered on eBay but I think it only fits up throuth 2016 models: http://www.ebay.com/itm/DUAL-F-250-F...kAAOSwrklVNPVD

 

Any update on this? I am also looking for the part numbers for the coolant tank and battery tray. Thanks.

 

Here ya geaux: HC3Z-8A080-D Expansion Tank

It is one part that includes the 2nd battery tray plus the expansion tank. The 2 bolts and same bolt holes holding your existing tank will be used to bolt down the new battery tray ...... The tank is held in a molded extension of the tray.

From what I could tell..... This is the same part whether u have the 6.7L diesel or the factory medium duty battery (dual battery) with the 6.2L.

I think all the plumbing, Attached hoses / wires, can simply be moved to appropriate positions on new tank. I am not positive about this but it looks like it will work.

I have the part.... Just have not had a chance to install it. Hope to get it done over the next week one day.

 

Can you post a few pictures of it? About $85? Thanks!

 

This summer my sons and I drove our 1975 FJ40 from the Black Hills to Saskatchewan without an alternator. By the time we got home the voltage on both batteries was 7.6 volts. Enough to keep the old dino running but not enough for signal or brake lights.
Would have never made it on one battery.
Now you can't do this with anything that has a computer, but it makes you think.

 

This is all one piece/part
Back of tank.....zoom to see wire/hose connection points
The 2 holes in bottom of tray use the same 2 bolts and holes used in the standard single battery 6.2L expansionn tank.
NOTE: there is a third hole in upper right corner of tray in last pic and there are 2 more holes in the side of the tray. These appear to be bolt holes and I haven't ID'd the location and bolts for these 3 holes. I actually just noticed them taking these pics.

I ordered from Tasca for $88 with $9 shipping = $98

 

Thanks! I will be following this thread closely as I plan on adding this asap.

 

Wow that is cheap.

 

Looks like duckduke pretty much has this covered but adding some pics for future reference.
6.2 ordered with dual battery
Hope this helps somebody maybe with seeing attachment points or orientation.

 

44Dan: One of my concerns/questions is whether that coolant elbow connector and hose between the expansion tank and the radiator is the same. It appears from your pics (the last 2 pics posted above) that it could be the same elbow connector/hose. I think the connector or elbow will simply rotate about 90 degrees between my current configuration and your dual battery configuration. At least I hope that's right. It appears that elbow will swivel.

LOL... one of my biggest hang ups on attempting this is how to deal with (change) the tank and fluid. The only thing I can figure is drain radiator til the tank fluid drops and catch the fluid to pour back in new expansion tank. I say LOL because of all the things....... this should be one of the easiest but I rarely ever touch coolant systems. I've certainly never dealt with a hose connection like on that elbow but it appears to simple.. Pull the wire retainer and unplug the elbow/tank. Oh well...... soon I hope.

 

Rather than drain the radiator, you might find it easier and less messy to siphon the coolant out of the tank.

 

I agree with wrvond - drain just the tank. You could even use a turkey baster to remove the coolant if that's all you had.

Very cool that you're going ahead with this. The wording is terrible - not sure how "Medium Duty battery" equates to dual batteries with the same rating as the diesel - but I was happy Ford offered it on the gas.

On the Powerstroke, dual batteries make sense considering the much higher compression ratio and the need to draw very high amperage prior to cranking in a short burst to heat the glow plugs.

On the gas, dual batteries are pretty unnecessary even with a plow, but you can never have enough power! In addition to the useful reserve if your alternator fails, I believe Ford envisioned the extra power for trucks operating with a very large accessory load. Dual batteries are priceless for winching, and would be great if attaching a large inverter directly to the batteries...or an underhood stick welder, etc.

Good luck! Of course you may just use the space provided rather than add the second battery...

 

Well the Fedex man showed up early with my tank from Tasca so I set about installing it. I learned a few things that will help anyone else doing this mod. I drained the tank by first disconnecting the small hose from the top of the radiator to the tank. Make sure you have something to catch the small amount of fluid that may drip out when you disconnect it. Also open the fill cap to relieve the pressure and the fluid should not run out this small connection very much. I probably lost a cup or so before I figured out that the smaller hose connection leaks until you crack the fill cap and relieve the pressure.


I took a long necked funnel and attached about 3' of tubing and ran it down to an empty pretzel container to catch the fluid. I was able to dump the fluid out of the top of the tank after I removed the cap with the elbow still attached by just swiveling the tank. About 2 gallons of fluid came out.


The elbow connection slides off very easily after you pull up the retaining wire about an inch or so. It is captive so don't pull too hard or it will come off. If it does, it pops back on so don't sweat it. Everything is plug and play to a point. The elbow does not swivel and it absolutely has to in order to make a connection. If you try to twist the hose without swiveling the elbow, the hose will kink. I had to cut the retaining ring, work a small screwdriver between the hose and the elbow to break it loose and then it would swivel the 90 degrees necessary to make the connection. I used a common hose clamp to secure the hose to the elbow. The original looks to be heat shrunk and cannot be re-used.



I disconnected the vacuum lines attached to the back of the tank and set them aside, they just snap onto the new tank with the same connections. I put the tray/tank in place and one of the bolt holes would not line up. I solved this by putting the two bolts in the bottom of the tray first and then pushing the tray in place. There is a locating tab on the side that will snap in and line up the bolt holes on the side. There is one bolt hole on the side of the inner fender that is there, but wasn't threaded on mine so I threaded it for a bolt I had in the shop. Also the other bolt hole on the inside of the fender is threaded, but you will need a shorter bolt since the factory one bottoms out before it is tight due to the thinner wall of the battery tray compared to the original tank mounting hole. I reconnected everything to the new tank and refilled the fluid. It went just past the minimum level on the new tank.
That's it. Now I just need about 10' of battery cable and a few clamps. I am probably going to run the cable along the back of the engine bay rather than across the engine like the factory. I don't think it makes a difference either way. I haven't decided whether I am going to run it in parallel like the factory or run an isolator. I will most likely run an isolator as that charges the second battery after the main battery is charged and prevents the second battery from running down. It automatically connects both batteries if it senses a large draw and allows you to "jump start" the original battery if it is dead without making any additional connections. Anyway, here is it after install:

The only thing you really need is a hose clamp and 2 shorter bolts for the side mounting holes, 1 if you don't want to bother to thread the hole on the inner fender.

 

Don't dual batteries have two alternators?

 

Not on the 6.2l gas engines. I have the snow plow prep that includes an extra heavy duty alternator so I’m sure it will handle charging 2 batteries.