Battery advice needed

[ert01]

I have an 02 E350 with the 7.3 diesel. It currently has the factory dual battery setup. (Cargo van I've been converting myself... Not a sportsmobile.)

As near as I can tell, the ford dual battery setup in my van uses the front battery as the starting battery and the aux battery by the frame rail as a house battery. I believe it isolates the batteries during starting and then connects them after the van is running. (Someone correct me if I'm wrong here?)

I plan to replace both the batteries and add one more house battery while I'm at it for a total of 3.

My van build is very minimal and the only constant load on the batteries is my ARB fridge. I don't have any water heater or air heater or microwave or anything like that. Only a fridge and a handful of LED lights inside the van.


What I'm thinking is that for simplicity sake, remove the isolator and run all 3 batteries in parallel all the time. That would help with rough starts in the winter and would also be more than enough AH's to run my lights and fridge for 4-5days in the summer when I'm camping away from shore power.

Now, is that an Ok plan or should I keep the isolator for some reason?

If I do delete it and run all 3 in parallel, should I buy all as starting batteries or all as deep cycles? I'll likely go with an AGM battery for all 3 due to the true maintenance free aspect of them.

Thoughts?

[alta825]

On my '02 7.3L it has the 2 battery setup as well. They are run together because the behemoth of the 7.3 needs them both to turn it over - the 2nd battery is not a house battery.

[1der]

As far as my understanding, all the diesel vans have two starting batteries, there is no "house" battery the way they are configured stock from the factory.

Therefore, you will need at least two starting batteries. AGM's would work for this, Group 65 is tfhe battery spec which fit the battery box in the engine compartment and the one on the frame rail.

For a house battery - this will be one or two batteries dedicated for camping use. This needs to have some type of isolation so the starting batteries are not drawn down for house use. An automatic isolator or a manual selector switch can be used to accomplish the isolation. I like the manual swithc but the vast majority use an automatic isolator.

If you are going AGM for your starters, then AGM for your house bank is desireable so all batteries have a relatively common charging profile. Two Group 31's@105Ah each or a 4D@210Ah will give you a few days of draw down on your fridge, which, if typical, is drawing about 40 amps per 24 hr period. If you are using the factory interior lights, replacing the bulbs with LED's will let you use the "starter battery" bank pretty safely if you are careful.

Where are you located?

[REF]

Yup, both batts you have now should be your starters, I would change them out and go all AGM, for both starting and house side, as Ray said, Deka(east penn), they also do some private labeling for some others, like Duracell, lifeline is another top choice, the house battery mounts up next to the 2nd starter up underneath. You'll probably want to add a solar panel and a charger to help keep things topped off. Lots of threads on the forum that talk about both battery and solar choices out there.

[ert01]

Well that certainly helps quite a bit... I'm located in Alberta so we get some nasty cold winters (-30C is very common). I do a lot of backcountry activities so it won't be uncommon for me to leave the van sitting in that sort of temperature with no block heater for a week at a time while I'm out skiing or snowshoeing.

I will eventually add a coolant heater, but I'd only use that for half the year... Batteries would get used for the whole year round so I feel upgrading the batteries is the best bang for my buck right now. Coolant heater can come later.

If I go with 3 AGM's in parallel with each other (no isolation at all) would it be best to get all 3 as deep cycle style or as starting style batteries?

[BajaSportsmobile]

Originally Posted by ert01

If I go with 3 AGM's in parallel with each other (no isolation at all) would it be best to get all 3 as deep cycle style or as starting style batteries?

That would be a big mistake. You could easily return from one of you described adventures to a van that won't start.

[1der]

Yep, what Ramsey said ^^^

Starting vs deep cycle - they have different purposes and a deep cycle battery does NOT like driving a starter and a Starter battery does not like being drawn down over time.

Sounds like an isolated house bank, a bit of solar to help supplement the fridge, are the way to go.

Save your starter batteries solely for starting the big diesel after it has sat for a week in the cold.

[ert01]

OK sounds like I need to go that route... separate house bank and starting bank.

Maybe I'll leave the starting bank as is and add an isolated house bank of 2 deep cycle batteries for now. Solar and coolant heater can be my Christmas project or something.

Thanks for talking me out of doing something silly That's why I asked here first before jumping right in on it all. Haha

[daveb]

Once you get solar I'd suggest purchasing a couple AGM starting batteries. Constant solar charging (depending on the system) can take a toll on wet cell batteries. Odyssey makes a great AGM starting battery that can be taken down to 80% depth of discharge as compared to a traditional deep cycle AGM that needs to be charged up at 50% DOD or a resting voltage of 12.2 volts. Odyssey batteries are expensive but worth it IMO. They are designed to work in high temps and are to military specs. BTW the Sears platinum AGM is a re-badge Odyssey but even those are expensive. When you spec a house battery it's worth knowing that the amp hours are basically cut in half due to the fact that you need to re-charge at 50% DOD. It's a reason most go at least with 200 amp hour battery. And make sure the manufacture uses the 20 AH rate in their specs...most do. As far as a separator I like the Blue Sea units ACR's and as mentioned will keep you out of a jam from waking to dead starting batteries. I also suggest getting a good battery monitor... for Christmas

Good info here:
http://www.solar-electric.com/deep-cycl ... y-faq.html

[E350]

Guys and ert01: As an alternative way to go, I like the Blue Top Optima battery which Ujoint just installed (a bunch of them) in the Optima SEMA van for a house-side set up. That Optima Blue Top is a hybrid starting/deeper cycle marine battery.

I don't know if two of them in parallel have enough cold cranking amps to start our 7.3s, but they have lasted nearly forever when I have used them in my Bronco's as a starting battery (on a battery tender when not in use). My idea is to have the same Blue Top Optima battery for house and starters, but not connected unless you need to jump your starting batteries from the house side batteries. By the way, I tried to jump start my van once from my 250 Ahr UPG deep cycle house battery and it didn't do it - at first at least. I needed to let the deep cycle slowly bring up the starting batteries to start the van (even if the 7.3 turns over it needs at least 10 volts or so for the injectors to be told to fire).

So, I am interested in (eventually) trying an alternative use/charging strategy which entails installing some Optima Blue Tops for the house side and draw them down to zero if necessary (yes "cycle" them) and see how it goes. Somewhere else I linked the charging discharging specs for the Optimas. If I recall correctly the Optima Blue Tops recharge more quickly than a true deep cycle. And I have depleted the ones that I have owned severely and they still lasted longer than any battery I have ever owned. So it is an intriguing idea to me.

Anyway, just a (heretical) thought for you to consider. (Although, I guess Optima must have also considered it because that's apparently how they rigged their SEMA van...) I emailed Optima Customer Service about this idea a month or so ago, and got an email back that they escallated my request. My guess is that I won't hear back until after they show their van at SEMA.