The Broccoli Bus

[family wagon]

I'll sign up as "it seems like a good idea and I'm interested, but can't spend the time working out the ROI/feasibility right now."

Mine presently has two 8D batteries for starting and two previously used J305 (I think) deep cycle for house battery. All are worn out. I haven't started the bus in almost a year and I'm not confident those 8D are going to be able to muster it, even in the summer. Maybe hot off the charger they'll stand a chance..

Anyway, I've been thinking real hard about building a battery with lithium prismatic cells to be used for both starting and house loads. Yes, yes, I know. I want to do it anyway. I'll have a 7 kVA generator onboard too (and already bought it, so it's not on the dream list still) so if we do find ourselves in a pickle where the battery can't start the bus engine it'll merely be a delay of a few hours waiting for the generator to make things right.

Between lithium tolerating deeper discharge than lead, but lead being cheaper than lithium, I'm hoping the analysis will find that lithium costs only 20%-30% more than lead for a given usable capacity. I'll be interested to see which direction you go with yours.

[dan-fox]

Originally Posted by cadillackid

temperature seems like the big disadvantage.. I owned a Chevy volt for 2 years.. and more than once the car got so hot that it activated its own Air-conditioner coolant circuit to cool down the batteries.. if charging it also greatly slowed my charging process.. if you are charging via solar efficiently you are likely also in an area that may be warm.. so thermal management is a biggie.. my car also wouldnt run on its batteries if they were below -15f, the car physically wouldnt work until its gas engine warmed up the pack enough to drive....

-Christopher

Yow! Between my family and my daughter's family, we've had 3 Priuses (Prii?) and never have I ever had hassles like that. It could be that living in the MidAtlantic has insulated me from that.

[aaronsb]

I got 4x 46 gallon water tanks. The dimensions are not exactly what I hoped for, but I think I can squeeze them in. I originally wanted to hang them centerline on the frame cross members but I can't wedge them in there with the luggage bay. I'd have to cut a big hole somewhere.

So, I'll make lemonade from the lemons and build a set of support brackets for the ends of the tanks, and some heavy channel between them. I'll be able to insulate the tanks with 2" of foam. I'll probably get some tank heater panels too.

[Tango]

Holy Moly! That's a lot of water! 1564 pounds to be exact. Are you planning on some kind of agricultural career for your bus?

[aaronsb]

3 girls, my wife, and then my son and I. Lots of water consumers. If it turns out we never need all that water then I can subtract some tanks.

Remember two of the four tanks are waste water, so technically it should never have all four tanks full, but it could (failing to drain waste tanks then take on fresh) so the hangers need to be robust.

Originally Posted by Tango

Holy Moly! That's a lot of water! 1564 pounds to be exact. Are you planning on some kind of agricultural career for your bus?

[family wagon]

That'll help pull the center of gravity back down after it was raised with the roof! Wow, that's (relatively) a lot of tension on the diagonals and compression on the segment at bottom between the tanks. At least to me it seems like it should be a lot. I can't quite read what channel you picked for it.. is that C with 2" flange, 3" web, and ?? thickness?

I was having tank envy at first (I have just two 42 gallon fresh) but since you clarified half of yours are for waste I feel better.

[aaronsb]

As for tension, yeah it's a little high. That's a good callout.

Maybe something like two hook assemblies that engage over the horizontal webbing on the vehicle frame on the top and bottom.Then those bolt onto the vertical support.

The hooks could be the 2x3 channel, back to back, with a spacer welded in the middle to account for the flange thickness of the frame.

That way the diagonal stringer pulls at a more rational angle and keeps the tension down.

So similar to a chassis frame bracket, but with a tie in the middle to lend more strength.

I am very averse to drilling holes in the frame in the middle of the bus.

The diagonal support can then run from the very top of the frame rail

Originally Posted by family wagon

That'll help pull the center of gravity back down after it was raised with the roof! Wow, that's (relatively) a lot of tension on the diagonals and compression on the segment at bottom between the tanks. At least to me it seems like it should be a lot. I can't quite read what channel you picked for it.. is that C with 2" flange, 3" web, and ?? thickness?

I was having tank envy at first (I have just two 42 gallon fresh) but since you clarified half of yours are for waste I feel better.

[aaronsb]

Should I be less fearful of drilling a few holes in the vertical web of the vehicle frame? 4 holes evenly spaced for perhaps a 1/2" bolt would be adequate to support the weight (x4 for each end and side) and make this whole thing a lot easier.

[EastCoastCB]

I say crack a few eggs, Aaron.

[aaronsb]

Originally Posted by EastCoastCB

I say crack a few eggs, Aaron.

[family wagon]

The problem with hanging them centerline as originally planned is that they'd fit the space, but only if they could somehow get through/around the narrow pass between frame and luggage floor? That's what I'm up against with one of my tanks. No luggage bay floor (yet), but I want one of the tanks above my wheelchair lift. I'll have to drop the lift a few inches, slide the tank in, then re-mount the lift. Not looking forward to it.

[skoolie_n00bie]

Originally Posted by dan-fox

Yow! Between my family and my daughter's family, we've had 3 Priuses (Prii?) and never have I ever had hassles like that. It could be that living in the MidAtlantic has insulated me from that.

Remember the Prius and the Volt are two different animals.
The Volt is designed to be primarily an electric car with gas genny assistance, the Prius is the other way around, basically.
I don't recall specs, specifically, but i believe the volt has more batteries, and they are li-ion vs the Prius having.....other types of batteries.
However this needs references, not just my brain vomit...

[aaronsb]

For me, centerline makes accessing the tanks in any way in the future nearly impossible. I saw an update from the Bertha Bus folks on facebook - they undersized the drain on the gray water, and the tank started accumulating sediment. No way to fix that other than get the tank out, and I can only imagine the work required if I have to cut structure out of the way to get the tanks in first.

There's simply not enough room to scootch the tanks in from the front, the angle is too tight to work around the fuel tank, and in the rear, the axle housing is in the way as well. That leaves slicing a big hole in the bay floor.

At that point, if you do get tanks in place, it's impossible to access any of the wiring and plumbing going down the frame (that had access ports before) or even getting to the hanger bolts for a centerline setup. Let's not forget that I'd have to lift the bus up to get the 15-16 inches of clearance to slide the tanks in from under. I don't have a 4 post hydraulic coach lift.

I'm pretty convinced the outboard tanks will work great.

I can disconnect fittings and slide them out easily enough.
There's room for insulation and plumbing.
There's now room in the middle for water pumps, filters, pressure bladders, and valving, which is still accessible just by the fact the tanks don't take up the fore to aft length up.

I'll still be able to install batteries centerline, however. They're just not as huge as the water tanks are. The clearance between lowest point on the frame to floor of the bay is 12", which is an inch larger than the height dimension of most batteries I'm looking at.

I would, dare I say almost state that a luggage bay is pretty limiting in some respects. In others it's nice because it is finished out with doors and a floor.

Originally Posted by family wagon

The problem with hanging them centerline as originally planned is that they'd fit the space, but only if they could somehow get through/around the narrow pass between frame and luggage floor? That's what I'm up against with one of my tanks. No luggage bay floor (yet), but I want one of the tanks above my wheelchair lift. I'll have to drop the lift a few inches, slide the tank in, then re-mount the lift. Not looking forward to it.

[Alan N]

Originally Posted by aaronsb

Should I be less fearful of drilling a few holes in the vertical web of the vehicle frame? 4 holes evenly spaced for perhaps a 1/2" bolt would be adequate to support the weight (x4 for each end and side) and make this whole thing a lot easier.

I would not be afraid to drill holes in the vertical frame web. Don't drill in the flanges however.

[thjakits]

Vertical Frame Web = the cross beams??

No problem to drill these AS LONG, as you stay away a prudent distance from the edges - THAT's where the forces pass through! Imagine to drill holes to lighten up the frame!!
And make sure they are de-burred! You don't want any hidden stress risers....
Also make sure that the stuff you bolt up doesn't introduce any twisting forces into the cross-members....copy what's already there from the factory!!

thjakits

[Tango]

If you are talking about the vertical portion of the main frame "C" channel, most manufacturers are adamant that no additional holes be drilled at all. GM has several safety bulletins that specifically address this issue.

[aaronsb]

The cross beams, aka "ladder rungs" already have enough holes I can use. I'm talking about the frame rails. I believe the rule of thumb is to stay in the center 33% of the vertical webbing. The least stress is in that location.

I've been looking at application guides for long haul trucks and semi trucks where additional holes are drilled for equipment and its not uncommon.

I still think it might be less "scary" to build some sets of hangers that reach around the flanges on top and bottom.

Would that be considered an incorrect way to load on the flanges, because its applying a point load?

I can't find any documentation about drilling holes in bluebird frames.

Originally Posted by thjakits

Vertical Frame Web = the cross beams??

No problem to drill these AS LONG, as you stay away a prudent distance from the edges - THAT's where the forces pass through! Imagine to drill holes to lighten up the frame!!
And make sure they are de-burred! You don't want any hidden stress risers....
Also make sure that the stuff you bolt up doesn't introduce any twisting forces into the cross-members....copy what's already there from the factory!!

thjakits

[aaronsb]

This is pretty neat:

Chassis Grabber

[RHOMBUS]

That chassis grabber looks cool, but I don't know how I'd slip that one part over the frame.

[cadillackid]

Originally Posted by skoolie_n00bie

Remember the Prius and the Volt are two different animals.
The Volt is designed to be primarily an electric car with gas genny assistance, the Prius is the other way around, basically.
I don't recall specs, specifically, but i believe the volt has more batteries, and they are li-ion vs the Prius having.....other types of batteries.
However this needs references, not just my brain vomit...

my volt had 16.1 KwH battery packs in it... the charge management system from chevy allowed the battery to use 10.1 Kwh of that.. thus always keeping the charge no lower than 20% and no higher than 80-85%.. the batteries also had extensive thermal management. under that arrangement you conceivabley can get 1000s of charge cycles out of your pack before it degrades...

battery degradation even on the oldest volts out there has been minimal compared to larger-range charge systems and non-thermally managed batteries like the nissan leaf or the smart-fortwo electric drive..

I sold my volt last year so I havent paid attention since then to the electric car forums of other models like the i3 or teslas to see if their packs are holding up..

the volt's battery pack is a 360 volt DC pack..

-Christopher