[nc rick]

I have searched the forum but have been unsuccessful at determining if my idea is viable; our t-250 has a single battery, mounted longitudinally ( relative to the vehicle ) in the battery box. I would like to remove the OEM single battery and replace it with two OEM type agm batteries mounted transversely in the battery box, like thy appear to be installed in the dual battery option. I am guessing, there will be no problem placing the batteries in there. Question is, will the battery cables reach one of the two new batteries? I want to use one of the two as the main, in a single battery configuration and use the second as an independent "house" battery to run my fan and stuff.

Has anyone done this or know if it will or will not work? Thoughts or knowledge to share about this potential modification will be appreciated.

 

[EddieZ]

It's been suggested, but, I don't think anyone has done it. Note that the regular (optional) 2-battery setup is already pretty crowded. And, they are pretty small, so, even if you succeed, you'll be limited in the number of amp-hours you can carry... 65, if memory serves. And, you'll only be using a fraction of that, to keep it in good service. 50%, or maybe less, depending on battery spec. So, you'd have a max of 32 amp hours available.

 

[EddieZ]

AND, a big disadvantage to the effort -- which I had considered when I got started -- is that you'd be buying not 1, but 2 new batteries. Your single flooded battery is bigger than the AGMs used in the dual setup. You can't get another battery in there, with the flooded battery.

EDIT: OK, I'm not 100% sure on this. I remember reaching that conclusion before knowing that the dual AGMs run transverse in the box. Note though, that there are contours in the box made to help secure the batteries, and they may be in the way for anything other than the normal dual AGMs.

 

[swellguy]

I have searched the forum but have been unsuccessful at determining if my idea is viable; our t-250 has a single battery, mounted longitudinally ( relative to the vehicle ) in the battery box. I would like to remove the OEM single battery and replace it with two OEM type agm batteries mounted transversely in the battery box, like thy appear to be installed in the dual battery option. I am guessing, there will be no problem placing the batteries in there. Question is, will the battery cables reach one of the two new batteries? I want to use one of the two as the main, in a single battery configuration and use the second as an independent "house" battery to run my fan and stuff.

Has anyone done this or know if it will or will not work? Thoughts or knowledge to share about this potential modification will be appreciated.

There's not enough room in there with the single battery setup to put a second battery with sufficient capacity for your house battery IMHO. I thought about doing this, but when I got it apart, the single battery is pretty big (I think they use 2 smaller batteries for the dual setup), so I don't think it's practicably doable. You might be able to fit something in there, but it would surprise me if it even had 30Ah. Also, I have an unenhanced base model so don't have an auxiliary fuse box in the seat pedestal for the additional CCP's. If you have those, I would imagine there would be even less room.

I used the space adjacent the single battery for wiring and circuitry to connect the house battery to the starter battery. The house battery is outboard inside the van right now, until someone comes out with an external battery box (I think Hein is working on one). Once that happens, I will drill a single hole down from the seat pedestal to the outside of the van and back where the batteries will be. My seat pedestal will also have a main fuse for the house battery, and a bypass switch for jumping the starter battery from the house battery in case of emergency. I'll post pics once I'm done.

Btw, the vent mechanism for the single OEM starter battery is very clever, it's simply a plastic adapter which covers the battery fluid fill holes and have a short piece of hose which goes through the floor of the van inside the seat pedestal to vent the battery - very slick imho. I'd love to find something like that for my house battery!

 

[nc rick]

Thank you for the excellent responses! It seems you both started with similar thoughts to mine. I really just want to run my fan for up to 12 hours on lower settings but I know I will add more stuff over time. My van also lacks the user connection points, it just has the plastic strip and cover to tease me. I will focus on an under body agm battery. Hein mentioned he was planning a box. That would be good, otherwise I will fab one up on my own. I came to the same conclusion regarding fitting a battery in the spare space under the driver seat. Perhaps I can mount a C - Tech in there. I don't like the idea of penetrating the floor ( or any part of my new van) so installing the fan was 14x14 therapy. Why stop now ;-)

Interesting factoid re: battery vent! Thanx. I took the battery cover off for a quick look but this forum has been my research portal. You guys are great!

 

[Budsky]

As for the empty connection point- it may be the electrical connections are behind it and it just needs the Ford fuse kit.
Mine had ONE CCP connection included- I bought the fuse kit to add the other two.

BTW the vent tubes for the 2 batteries in my diesel do not penetrate the floor- they just hang there in the plastic tub battery box.

 

[nc rick]

Budsky, I took my ccp cover off and there are three smallish studs, about 5mm from memory. Two on the outside looked like they hold the plastic connector block on and a third, similar looking one in the middle. It looked like room for two others, one on each side with three total that would be separated by the dialectic "fences". I did not take the fuse or battery covers off but my multimeter showed no voltage to ground from what I saw. Is that similar to what you found? Thanks!

 

[Budsky]

Yes! I had one in the middle and the fuse kit added the other 2 studs, fuses and connection bars to the buss.
The single one on mine was hot with 12V though before I added the other 2.
Seems odd though they'd put the stud there but not install the fuse with it....

 

[nc rick]

I'll be checking! I did get the "cheap" model. ;-) I'll reserve additional questions until after I look in there harder. Thanks so much!

 

[justcallben]

Bump and overrule!

I know this thread has been dead for several months but I finally got the time to do my dual battery upgrade.

I was shoppin' like a mad man for two new AGMs and was pretty pissed that I'd have to ditch my less-than-1-year-old factory battery. So, I did some more measuring and figured out how to shoehorn another Group 48/H6 in with the original!

By removing the OEM battery box and fabbing a tray, I got both batteries mounted laterally.



I then used the plastic retainer from the original battery box as a spacer to hold the batteries laterally. Then a piece of 3/8 plywood under the hold-down bar as a spacer for that. A couple of patch cables and whammo! No more dead battery for Ben.



So, you can fit a second battery in there if you ditch the factory battery box. Heck, there's another 2 inches if you wanted a bigger battery. But the big limiter is height. Because of the hold-down bar and the seat you really don't want to go any taller.

 

[Oyaji]

Nice. Is your stock alternator happy with the setup--and does it keep both batteries charged? Any other problems with the electrical system caused by this?

 

[pjtezza]

My van came with a single lead acid battery. I added a second AGM battery in the OEM battery box under the driver's seat as a house battery. I cut off the OEM cable ends and crimped on ends that had better support for multiple connections. I had to modify the OEM battery box a bit to get both batteries to fit. The result works and is should be be fine to power a fan and some LED lights for several days. However, replacing the OEM cable ends isn't for everybody (use the CCP instead). Modifying the battery box then squeezing the big cables in is a lot of hassle. I would recommend considering Hein's undermount battery box.

Here is a link to an older post with more details: http://www.fordtransitusaforum.com/...istan-minimalist-diy-camper-6.html#post463673.

The Transit has two different alternator options, but even the basic Transit alternator should have no problem charging two or more batteries.

 

[sschefer]

Nice. Is your stock alternator happy with the setup--and does it keep both batteries charged? Any other problems with the electrical system caused by this?

Here's how the smart charge system works: http://www.fordtransitusaforum.com/engine-technical-discussion/40753-smart-charge.html#post509625

Ford sells our vans with two battery options, Single Silver/Calcium sealed lead acid and AGM (single and dual). The Silver/Calcium requires a much higher flood voltage when charging than a AGM can handle. I have heard that there is a setting in the PCM to change the charge method from Silver/Calcium to AGM.

I personally would never mix the two types. With that said, I have been monitoring my single Silver Calcium battery with a Victron 702 BVM and the history logs show that my max voltage has never gone above 14.55v which is perfectly safe for AGM batteries.

The 150 amp alternator is perfectly capable of charging both batteries but, don't expect them to be fully charged after a quick freeway run, if they've been drained down to 40% remaining.

Ford sells the dual battery upgrade kit (sans batteries). This is what I plan to use for my dual battery upgrade if I do it. Both of my batteries will be AGM's and I plan to take the van in and have the PCM updated before I do the install. Better to be safe than sorry, AGM's are not cheap.

 

[pjtezza]

Haha, I'm a battery chemistry mixing rebel! Actually, I paid $120 for my AGM (including shipping) and my lead acid battery was brand new, so I decided to just try it and see what happened. At this point, my AGM has been run down and charged quite a few times and it seems fine... probably just cursed myself though. The area under the seat is limited. The height constraint limits to group 48 and, with 2 batteries, there isn't a lot of room left for cables. The major benefit to this setup is that it is low cost. I suppose if you knew in advance how to modify your battery box (or bought the upgrade kit) and how to route the cables, the install could go quickly, but in my case, getting the batteries and routing and protecting the cables involved time consuming trial and error.

 

[justcallben]

Nice. Is your stock alternator happy with the setup--and does it keep both batteries charged? Any other problems with the electrical system caused by this?

Thus far the batteries are performing above my expectation as far as depth of charge and capacity. Previously with the anemic single Motorcraft battery, I had four jump start events after parking at jobsites and leaving the doors open. No radio or any other draw, just factory LED lighting for the cargo area.

One concern I have is the charging voltage. I have installed a meter/USB adapter in the outboard power socket. I have not tested it's accuracy so I can't be certain that the numbers are valid. It reads anywhere from 12.6 down to 11.8 while the motor is off. When running, the voltage begins as high as 14.7 and typically settles around 14.1 even after more than an hour driving. It should be 13.8 nominal.

I have a panel voltmeter that I will be installing soon and that should give me more accurate readings. If I continue to have anomalous readings, I will have the dealer perform a charging system test.

Also, I have since found that I can install the factory battery cover under the hold down bar and eliminate that plywood spacer.

 

[justcallben]

Haha, I'm a battery chemistry mixing rebel!

I was originally set to do the same and after researching the options and discussing the plan with trusted sources, I decided against it.

The AGM can't handle the higher flood voltage for a prolonged period of time. Yes, it will work for a while but you've probably shortened the life of the AGM by 4+ years. Also, I found a higher capacity SLA battery (in Group 48 from NAPA) than any AGM I could find. That sealed the deal: no mismatched batteries and better performance for less money and a warranty from a local shop.

 

[sschefer]

Thus far the batteries are performing above my expectation as far as depth of charge and capacity. Previously with the anemic single Motorcraft battery, I had four jump start events after parking at jobsites and leaving the doors open. No radio or any other draw, just factory LED lighting for the cargo area.

One concern I have is the charging voltage. I have installed a meter/USB adapter in the outboard power socket. I have not tested it's accuracy so I can't be certain that the numbers are valid. It reads anywhere from 12.6 down to 11.8 while the motor is off. When running, the voltage begins as high as 14.7 and typically settles around 14.1 even after more than an hour driving. It should be 13.8 nominal.

I have a panel voltmeter that I will be installing soon and that should give me more accurate readings. If I continue to have anomalous readings, I will have the dealer perform a charging system test.

Also, I have since found that I can install the factory battery cover under the hold down bar and eliminate that plywood spacer.

I doubt you'll ever see 13.8 (absorb) or 13.2 (float) since there is always some load present during driving.

If anybody is interested, they don't seem to sell the kit anymore. The minimum basic parts are:

1 - 14300A
1 - 14300B
2 - 14450
3 - HN2

Cost is about 85.00 plus tax and shipping. You can order them at the Ford Parts website but you have to sign up first.

There is one more cable but it's just a jumper so you can make that yourself. Cable size is 1/0. In fact, if you don't mind making your own cables then the two 14450 are the only things you might want to buy to keep it all looking factory.

 

[justcallben]

I doubt you'll ever see 13.8 (absorb) or 13.2 (float) since there is always some load present during driving.

Actually most of my other vehicles with correctly operating charging/starting systems would run at 13.8 while operating normally. I agree that float is usually never seen.

 

[orton]

I just avoided the question about getting a correct charge from the vehicle alternator. Never directly connect my house battery to the vehicle battery.

Installed a pure sine inverter powered by the vehicle 12 volt system. That gives me "shore power" with the engine running. The "shore power" can be used to power the house charger if I need charging from the vehicle. My primary source of charging is a single 300 watt solar panel with a MPPT solar controller. I seldom need to charge with shore power. Whichever charging source that is used I get a correct 3 stage charge profile for my house battery.

As a side benefit with engine running, the vehicle powered inverter can provide 120 volt AC power for other uses. I use two selector switches. First one selects real shore power or vehicle inverter "shore power". Second selector switch directs the power where I want it to go. Second switch can connect shore power to the charger or to the shower water heater or to the 750 watt electric baseboard heater. Due to the size of the vehicle powered inverter, only one choice can be used at the same time.

 

[NetDoc]

You can't get another battery in there, with the flooded battery.

This was my experience and I added a battery box behind my seat. I have a custom charging station for all my diving cave lights and such, so I needed the extra oomph.