Sprinter or Transit?

[T town]

They are about the same. Short Sprinter, high roof is 19'4" long on 144 wheelbase, 6'3" high inside and 123" long inside. Midsize Transit is 19'8" long on 148" wheelbase, 6'5" high and 124" long inside. So Transit inside has 2 inches more headroom and 1 inch more "legroom". They both 69" wide inside. Promaster beats them both here, with 73" wide body. It is also 2 inches longer inside then Ford, but 3 inches lower.

We are planning to add body flares to be able to build a bad "sideways", because with 20 foot Van there is no room to waste, but we don't want to go over 20 feet with our mini-RV

Mercedes-Benz Sprinter Van + Dimensions + Comparisons - Conversions

The Mercedes Sprinter is an exceptionally engineered and designed van that’s well suited for a Sportsmobile conversion. View van dimensions and comparisons

sportsmobile.com

IDK where Sportsmobile gets their numbers but it looks like the midTransit has a 6’ high Interior and the high is about 6’9”.
I’d hate for you to order one thinking it was 6’5” in there.
This is from Ford’s website.

 

[Polonus]

Yes, but with a 50A charger, it'd take driving all day to charge your 400aH battery set.
With a relay, and the 220-250A alternator, it'd take a few hours.

I understand this, but what I have problem with understanding is if I can connect LiFePo4 batteries directly do the 2nd "smart" alternator in the Sprinter. I am getting mixed information here and I don't know which is correct.

That van has the load protection package. This package protects sheet metal but covers up a lot of other stuff. Just above the lower panel the sheet metal makes a bump out on both sides. Try to look at a pic on the web of a Transit without that package. Most people put their bed up that high, maybe 2.5 feet on the low side, and you are supposed to have around 6 ft of width up there.

Wrong. You were in a van with the wall panels covering the window indents. You need to remove the plastic wall coverings to get maximum bed length. In a van without the plastic wall covering the bed length is significantly longer. As I said my Transit bed length is 73 3/8" with 1 1/2" of rigid insulation covered by 3/16" thick indoor/outdoor carpet. Just remeasured it to confirm the length. Top of bed surface is about 32" above the steel floor. Go to Ford dealer and measure inside van width in a bare interior without the panels. You do not need flares at your height. See post #34 above for a picture of van without the wall panels. Note the additional depth in window indents behind the wall coverings.

See the left picture on this link. Note the steel above the window indent insulation. That is the surface the plastic wall coverings are attached to. Note how much horizontal steel is above the insulation from the upper panel surface back to the insulation.. That length of that steel and the wall covering thickness are added to the bed length on both sides. I am 5'-10" and sleep across the back of the van without being diagonal.

I hope you are both right. I will remeasure it again. I'd love to be to be proved wrong.

With either the Sprinter or the Transit the wall coverings need to be removed.

I know that, however possibly I still would order them, to use them to cover van's insulation.

The Transit system sounds very attractive.

But can connect LiFePo4 batteries directly to that second alternator?

IDK where Sportsmobile gets their numbers but it looks like the midTransit has a 6’ high Interior and the high is about 6’9”.
I’d hate for you to order one thinking it was 6’5” in there.
This is from Ford’s website.

MR is definitely to low. I will go for the High Roof.

 

[avanti]

But can connect LiFePo4 batteries directly to that second alternator?

The second alternator is typically installed along with a combination voltage regulator/battery charger--often a Balmar unit. These are programmable, including with a lithium profile. It is electrically independent of the Sprinter.

 

[RVBarry]

Yes, Balmar or Wakespeed regulators work well with lithium.

If you're using dumb batteries, an additional battery manager is a good idea...
There's more information in this thread:

DIY Lithium Batteries charged by 2nd Alternator set up

I am considering a lithium battery system charged by a 2nd alternator. Would like option to add solar later but right now with paddle boards and kayaks planned to go on top we will see if alternator and maybe Honda 2200 generator will work for us. We are planning on ordering a 2020 Sprinter...

sprinter-source.com

 

[RVBarry]

I understand this, but what I have problem with understanding is if I can connect LiFePo4 batteries directly do the 2nd "smart" alternator in the Sprinter. I am getting mixed information here and I don't know which is correct.

See my comment above about dumb batteries.

Also note it is not recommended to charge at a faster rate, in Amps, than 1/2 of C, the battery bank's TOTAL capacity in aH.
So for a 250A dedicated alternator, the bank should be at least 500aH, or the regulator needs to be managed somehow.
For a small battery, a DC DC charger would prob be wisest.

Re "2nd 'smart' alternator in the Sprinter"
Note any additional alternator in Sprinters is aftermarket, so it's not 'smart' in the way that some of the MBZ hybrid-charging alternators are.


See also

Add 2nd Alternator....

Hello friends, I have a 2019 Mercedes 4 x 4 Sprinter 144" I need to have a second alternator installed for the lithium batteries that I will be installing. My van does not currently have the N62 bracket installed that I have been told I need. Looking for suggestions on where to get this...

sprinter-source.com

BTW, if you use a relay to connect the battery bank to the SINGLE alternator, it is unclear to me how long that will take to FULLY charge if it's one of the new smart alternators.

 

[Polonus]

Re "2nd 'smart' alternator in the Sprinter"
Note any additional alternator in Sprinters is aftermarket, so it's not 'smart' in the way that some of the MBZ hybrid-charging alternators are.

I meant Transit. Looks like I made my choice. It will be a Ford, with factory second alternator.

 

[Kajtek1]

I just sold my Ford Truck that I custom-order 3 years ago.
At 20,000 miles the oil pan start dripping. Warranty cover that, but I heard engine had to come out for the job.
100 years in business and Ford can't make reliable oil pan gasket for their flagship engine ??? It had dual alternators btw, becouse unlike Sprinter - Ford can't make 250 amp alternator for electric cabin heater.
So good luck.

 

[Polonus]

I just sold my Ford Truck that I custom-order 3 years ago.
At 20,000 miles the oil pan start dripping. Warranty cover that, but I heard engine had to come out for the job.
100 years in business and Ford can't make reliable oil pan gasket for their flagship engine ??? It had dual alternators btw, becouse unlike Sprinter - Ford can't make 250 amp alternator for electric cabin heater.
So good luck.

Ford sells millions of trucks with that engine. How many of them has that problem?

 

[Graphite Dave]

I hope you are both right. I will remeasure it again. I'd love to be to be proved wrong.

Not trying to prove you are wrong. Just trying to save you the expense of flairs that you do not need.

 

[avanti]

It had dual alternators btw, becouse unlike Sprinter - Ford can't make 250 amp alternator for electric cabin heater.
So good luck.

Actually it has dual alternators so that unlike Sprinter Ford allows upfitters to take off 175A of current. Sprinter allows 40A.
So good luck.

 

[OrioN]

Actually it has dual alternators so that unlike Sprinter Ford allows upfitters to take off 175A of current. Sprinter allows 40A.
So good luck.

 

[HarryN]

Earlier you asked the question about what this all means in terms of charging up the battery pack.

I am lazy, so I am going to do some heavy rounding of the numbers.

If you have either the Transit 150 amp or Sprinter standard alternator, you can count on pulling ~ 40 ish amps, so 400 watts.

The Transit dual 250 alternator factory setup raises this to ~ 2000 watts.

Depending on what after market dual alternator you put on the Sprinter, you can pull 4000 + watts.

At the 4000 watt level, I think the big advantage that the Sprinter has is that you are not stuck with 12 volt output to the auxiliary battery pack. Trying to move 4000 watts using 12 volts from the engine to the aux battery pack is very challenging, but relatively easier at higher voltages.

For your ~ 4000 watt-hr battery pack:
- Assume for the moment that it is at 25% SOC (1000 watt-hrs) and you charge for 1 hr
- The 400 watt charge rate will take it up to 1400 watt-hrs
- The 2000 watt charge rate will take it up to 3000 watt-hrs (75%)
- The 4000 watt hr alternator can run an RV roof top air conditioner, make coffee, your wife can blow dry her hair, and charge at 2000 watts to bring it up to 3000 watt-hrs while you drive down the road.

Each van has its place.

 

[avanti]

Earlier you asked the question about what this all means in terms of charging up the battery pack.

I am lazy, so I am going to do some heavy rounding of the numbers.

If you have either the Transit 150 amp or Sprinter standard alternator, you can count on pulling ~ 40 ish amps, so 400 watts.

The Transit dual 250 alternator factory setup raises this to ~ 2000 watts.

Depending on what after market dual alternator you put on the Sprinter, you can pull 4000 + watts.

At the 4000 watt level, I think the big advantage that the Sprinter has is that you are not stuck with 12 volt output to the auxiliary battery pack. Trying to move 4000 watts using 12 volts from the engine to the aux battery pack is very challenging, but relatively easier at higher voltages.

For your ~ 4000 watt-hr battery pack:
- Assume for the moment that it is at 25% SOC (1000 watt-hrs) and you charge for 1 hr
- The 400 watt charge rate will take it up to 1400 watt-hrs
- The 2000 watt charge rate will take it up to 3000 watt-hrs (75%)
- The 4000 watt hr alternator can run an RV roof top air conditioner, make coffee, your wife can blow dry her hair, and charge at 2000 watts to bring it up to 3000 watt-hrs while you drive down the road.

Each van has its place.

This is all correct.
Note, however, that, at least with the Nations' alternator, you won't get 4000 watts continuously. The regulator will cycle down the output pretty significantly in order to keep the alternator cool. I have previously published a graph showing this on my Nations' setup. There are other (although pricy) alternatives available that avoid this issue.

The 175A from the Transit purports to be continuous.

The "not limited to 12V" observation is well-taken.

 

[HarryN]

This is all correct.
Note, however, that, at least with the Nations' alternator, you won't get 4000 watts continuously. The regulator will cycle down the output pretty significantly in order to keep the alternator cool. I have previously published a graph showing this on my Nations' setup. There are other (although pricy) alternatives available that avoid this issue.

The 175A from the Transit purports to be continuous.

The "not limited to 12V" observation is well-taken.

Exactly. Nation's (and others) make very nice 12 volt alternators. The 4000 watt version that I was referring to aren't 12 volt and make the Nations offering look very reasonably priced. The $/watt are similar.

 

[Polonus]

Not trying to prove you are wrong. Just trying to save you the expense of flairs that you do not need.

I know and I do appreciate all of the advice you are giving me. And I have to say: I was wrong. I was only able to measure the low roof van, but it shouldn't matter, I think. Width should be the same. And it was, from window panel to window panel, 77 inches, ot 6 feet 5 inches. Even if I loose several inches for the insulation, I'll fit with room to spare.

The Transit dual 250 alternator factory setup raises this to ~ 2000 watts.

- The 2000 watt charge rate will take it up to 3000 watt-hrs (75%)

Since I am almost certain it will be a Transit with dual alternator, I am quoting only numbers for that vehicle. So... If I have 400 Ah 12 V LiFePo4 battery pack, how long I have to drive to charge it? How do I "translate" 3000 Watt-hrs to Ah? Since it is 12-V system, does it means it will charge with ~ 20 amps? About 20 hrs? With 1000 Ah 48 hrs?

The "not limited to 12V" observation is well-taken.

What is the advantage of going to 48V instead of 12V? Can the Transit charge it?

 

[Kajtek1]

Picture is not showing where did you stop the tape measure, but my bus from glass to glass has 75 inches

 

[T town]

BTW, the higher power CCP is fused at 175 amps. Approach that number at your own risk. Blowing the fuse means removing the front seat or at least pushing it forward and changing it. Not a plug and play like you think of in a car’s fuse box although Transit has those also.

 

[avanti]

BTW, the higher power CCP is fused at 175 amps. Approach that number at your own risk. Blowing the fuse means removing the front seat or at least pushing it forward and changing it. Not a plug and play like you think of in a car’s fuse box although Transit has those also.

Is there a published maximum amperage?

 

[Polonus]

Picture is not showing where did you stop the tape measure, but my bus from glass to glass has 75 inches

I measured it from metal to metal. Windows may be mounted "inside" and glass probably is thicker then metal skin. However two inches will not make any difference, if I can get bed about 70-72 inches long, I'll be happy.

We are going to have all metal van and I didn't decided yet if I want small window on one side, by my head, for nice breeze at night, or to go with "stealth look" and no windows at all.

I'll have roof AC above the bed and roof vent in front, plus small fans, so ventilation should be sufficient even if we do not have any windows. Or we could add that later - by the bed it will be only thin insulation.

BTW, the higher power CCP is fused at 175 amps. Approach that number at your own risk. Blowing the fuse means removing the front seat or at least pushing it forward and changing it. Not a plug and play like you think of in a car’s fuse box although Transit has those also.

I may have to change some of the electric wiring all together and I will not do it myself. I'll hire the professional to do this job. Since my van will be "all electric", with huge batteries, I will need someone who knows what to do and how to do it.

 

[Kajtek1]

I made my RV stealthy with windows all around and even with that I made the dinette open to the rear.
You don't want to spend your vacations sitting in dark rat hole.