What is the max amount of weight a bare 40ft skoolie can carry?

[301kwBlueBird]

I work for a lithium battery refurbishing/up-sycling warehouse and over the years got my hands on a lot of great lithium battery deals, so my electric skoolie dream is very close to come true.
I have roughly enough batteries to convert a 40fter to fully electric but the final battery size depends on the max amount of weight the frame can carry on itself.


I've tried to find a list of busses and max weight capacity with no luck.

The engine will be replaced by an electric one so there will be some weight shaven off right there. If anyone knows how much the whole engine weights please let me know.

[musigenesis]

The biggest school buses have a GVWR (gross vehicle weight rating i.e. the maximum allowed total weight of the vehicle including passengers, fuel etc.) of 33,000 pounds.

A Cummins 8.3L (common in older 40' buses) weighs about 1600 pounds.

[TaliaDPerkins]

You mean 16,000 lbs ?!

[DeMac]

Welcome to the Insane Asylum, 301kwBlueBird.



IC RE300s have a maximum GVWR of 37,000 lbs, ours is labeled 35k. The engine weighs 1900lbs. The trans weighs 530lbs.

I found this info by typing "GVWR RE300" into Google. Wikipedia provided the results.

My next Google search:
"Due Diligence"

[Tejon7]

My Crown had a GVWR of 37,400 lbs. It weighed very close to 20k lbs pre-conversion with the seats stripped out. My engine supposedly weighs 2200 lbs and transmission weighs 600. By my math, that would give you just over 20k lbs for batteries and motor(s) if you simply wanted an empty 40' golf cart

[301kwBlueBird]

Originally Posted by Tejon7

My Crown had a GVWR of 37,400 lbs. It weighed very close to 20k lbs pre-conversion with the seats stripped out. My engine supposedly weighs 2200 lbs and transmission weighs 600. By my math, that would give you just over 20k lbs for batteries and motor(s) if you simply wanted an empty 40' golf cart

Thanks, this is really helpful!

Anyone knows what would happen eventually if the total gvwr is exceeded by let's say 2000 pounds? 4000lbs?

And how can one improve the gvwr? Is it possible to spend some money/time and reinforce something?

[fo4imtippin]

U bolt snapping, Axle breaking, wheels breaking off, inability to stop safely. GVWR is how much can ride on the machine. You can tow a trailer behind if there's more weight to pull.


That said, you can add more capacity, by swapping axles to something bigger, but you have to reinforce things like the frame and suspension. These things are calculated by engineers at the factory, and i don't recommend you attempt to exceed the limit. Its much cheaper or practical to buy a bigger vehicle. If you are looking to haul more than 36k total weight, then i want to hear what you are hauling!

[TaliaDPerkins]

What I meant by 16,000lbs is, there is a GVW usually on the order of 35,000 with the bare vehicle already weighing 16,000 -- so frequently a 19,000lbs maximum added during a build . . .


. . . and it's a bad idea to crowd the maximum. The axles have a listed total maximum for the two of them added together.

[301kwBlueBird]

Originally Posted by fo4imtippin

U bolt snapping, Axle breaking, wheels breaking off, inability to stop safely. GVWR is how much can ride on the machine. You can tow a trailer behind if there's more weight to pull.


That said, you can add more capacity, by swapping axles to something bigger, but you have to reinforce things like the frame and suspension. These things are calculated by engineers at the factory, and i don't recommend you attempt to exceed the limit. Its much cheaper or practical to buy a bigger vehicle. If you are looking to haul more than 36k total weight, then i want to hear what you are hauling!

I'm trying to haul as much lithium battery range possible.

I have about 4000 ebike and escooter batteries at 4.7lbs each so the range isn't a problem, it's the maximum weight the vehicle can carry. The batteries are gonna be in the floor, equally distributed weight wise between the axles.

I thought about a trailer, but at all 40ft plus trailer length makes it a bit difficult to park in cities, it's like a semi at this point.

I haven't seen a 40ft electric conversion yet so I need to find out all these details to understand the range possibilities of this potential build. I'm aiming for 250-300 mi range on one charge, not trying to travel long distance much. Plus with all the chargers available around, a quick top off is always available.

[DeMac]

Originally Posted by 301kwBlueBird

I haven't seen a 40ft electric conversion yet so I need to find out all these details to understand the range possibilities of this potential build. I'm aiming for 250-300 mi range on one charge, not trying to travel long distance much. Plus with all the chargers available around, a quick top off is always available.

Several companies have been converting 40ft buses to electric: Lightning E-Motors, Unique Electric Solutions, SAE Electric & Midwest Transit Equipment are all converting diesel buses to electric. You may be able to see one of them, in your area, soon.

Are you noticing alot of public chargers which are easily accessable to oversized vehicles? Seems buses are mostly fleet owned, not refueling at the local 7-11.

[301kwBlueBird]

Originally Posted by DeMac

Several companies have been converting 40ft buses to electric: Lightning E-Motors, Unique Electric Solutions, SAE Electric & Midwest Transit Equipment are all converting diesel buses to electric. You may be able to see one of them, in your area, soon.

Are you noticing alot of public chargers which are easily accessable to oversized vehicles? Seems buses are mostly fleet owned, not refueling at the local 7-11.

Not many, no, but with long enough cables anything is possible lol.

I'm planning on being absolutely self sufficient in terms of charging tho, solar array that turns into an awning and tilts towards the sun, multiple wind generators and other solutions, even a generator for emergencies.

[Ronnie]

Thomas bus does build all electric buses. You should be able to find the range and kw capacity of their batteries. This would give you a good starting point. I believe around 125 miles or so is the advertised range, so double the batteries gives you the 250 miles you want.



Just remember more weight needs more power to move.

[301kwBlueBird]

Here's a list of relevant to this topic stats from the Thomas bus website

PASSENGER CAPACITY

Up to 77

GVWR

Up to 33,000 lbs.

BATTERY ENERGY

Up to 220 kWh Power

ELECTRIC SYSTEM

295 Peak Horsepower

0-60 MPH Acceleration in 49 Seconds Depending on Final Drive Ratio

So at 33k it can go for roughly 120 miles with a 220kwh battery pack.

Let's say fully loaded at 37k the range will decrease even more, 1 mile per 2kwh.

I have two types of batteries, one having the best cells meaning more energy per weight, the other ones are second best, lacking about 10 percent of the first ones capacity.

Sanyos = 8.15 lbs per kwh

Lg = 9.17 lbs per kwh

300 mi = worst case 2700 lbs best case 2500 lbs

That's awesome!! I was worried it would take like 10k pounds or so!

I'm probably gonna build a bigger battery now, since there's so much more weight I can play with.

[jbeech]

So I think a realistic way of backing into this number is count the number of kids it was made to carry and multiply by 150lbs.


As for how stuffed with lithium packs you want to make it, it depends on the cells. If they're A123 type LiFePO4 cells, the answer is as many as you want to deal with. Anything else, LiPos for example, my answer is as few as possible, zero is best. Your mileage may vary.

[Unpluggedone]

Very ambitious. So couple things. You cannot exceed the Gross Vehicle Weight under any circumstance, brakes come to mind, but liability not to mention insurance, think you’re figuring that out. The electric conversion is simple in theory, less complicated than Internal Combustion, but man there are a lot of very scary things to consider. Lithium Batterues are a fire waiting to happen. The Battery Management System is the big nut to crack, not exactly a part you just go and buy off the shelf. If you’re parked somewhere permanent then you can build a 10,000 watt array and take a stab at charging your batteries. But unless you use a standard and certified charging system Charge America, Tesla or anyone else will not let you use their system.

Love more details will be exciting to watch.

[turf]

whats your drive train?

Meritor has some electric drive trains, the 12Xe and 14Xe. i think the 12 is what is currently in busses. looks like the max on those axles is 30k combo.

https://www.meritor.com/en/products/ePowertrains/12Xe

[IDoMy0wnRacing]

The number of axels could play a part.
My 1977 40' Gillig has tandem axle and has a GVWR of 45180.
The 1980 35' Gillig is single rear axle has a GVWR of 35200.

Getting a tandem axle 40' could get you nearly 10000 pounds more GVWR.

[Dirtdoctor]

Originally Posted by 301kwBlueBird

Thanks, this is really helpful!

Anyone knows what would happen eventually if the total gvwr is exceeded by let's say 2000 pounds? 4000lbs?

And how can one improve the gvwr? Is it possible to spend some money/time and reinforce something?

Hold on, weight ratings are posted on your TAG on the bus, look for the mfg tag, it is about 4” wide amd 10” long has you vin date and type of bus, along it has axel weights and GROSS VEHICLE WEIGHT RATING. GVWR- That weight is the max that the bus has been engineered for, that means anything heavier amd it will be a problem, braking ability, tires (weight rating) over load tires amd they will wear quickly and blow out transmissions and suspensions are spec’d for a specific weight. Plus if you are ever in am accident, no matter who is at fault, you can be sited for overloaded. And insurance would be dropped. So. Fine a bus with the proper weight rating ( the weight is max load with fuel, passengers amd equipment.)
Cheersl

[HamSkoolie]

Originally Posted by fo4imtippin

That said, you can add more capacity, by swapping axles to something bigger, but you have to reinforce things like the frame and suspension.

DO NOT DO THIS
While it is physically possible to upgrade things, the VIN number and the data plate dictate GVWR of a given rig. Exceeding the manufacturers GVWR for your rig is a perfect recipie for a lawsuit and/or criminal charges.


DO NOT EXCEED THE GVWR


DO NOT EXCEED AXLE RATINGS


DO NOT EXCEED TIRE WEIGHT CAPACITY


In a crash, you WILL have the potential to be hung our to dry.


I just read a case where a truck driver going down the road at 43mph on an expressway (multi lanes each direction and a big median like an interstate) was hit by a car that crossed the median and hit the truck head on. The jury assigned 70% fault to the truck company and 14% fault to the truck driver and only 16% to the driver that crossed the median.
Two kids were killed, a third received serious injuries and their mother (all were passengers in the median crossing vehicle) received some brain injury.

So the jury undoubtedly was just like the one I sat on with people saying "well that poor family lost everything and he's got insurance". In my case it was three people and we convinced them that that was absolutely wrong. In this case, a few more idiots were present on the jury.


If doesn't even matter if it's your fault the accident happened. If you're over weight on the chassis, axles, tires, ANYTHING, you will be destroyed. You might even get criminal charges.

[Iceni John]

Some (but not all) Crown tandems, i.e. with dual rear axles, had GVWRs in the 48,000 lb range. They are essentially Class 8 trucks underneath the school bus body, with massive axles and brakes. Mind you, the Crown afficionados on the CCJ forum would have the heebyjeebies if they heard that you were going to seriously molest one of their beloved tandems.

Good luck!

John