Winter Reliability Issues for EV Buses in Vermont

[Larry N.]

Check out this problem with EV buses:

Vermont EV Buses Prove Unreliable For Transportation This Winter - Slashdot

An anonymous reader writes: Electric buses are proving unreliable this winter for Vermont's Green Mountain Transit, as it needs to be over 41 degrees for the buses to charge, but due to a battery recall the buses are a fire hazard and can't be charged in a garage. Spokesman for energy workers...

tech.slashdot.org

 

[John From Detroit]

That is an easily solved issue and in fact several battery makers make batteries with the "Fix" already installed... A battery heater. thermostatically controlled. First it heats the battery to "Safe charge" then it switches over to "Charge" and after that the charge current continues to heat.

 

[DutchmenSport]

That is an easily solved issue and in fact several battery makers make batteries with the "Fix" already installed... A battery heater. thermostatically controlled. First it heats the battery to "Safe charge" then it switches over to "Charge" and after that the charge current continues to heat.

and all that switching back and forth is draining the battery until its dead! Now the battery freezes and ....

 

[DonTom]

Check out this problem with EV buses:

They have no outside way to charge?

I would like to know all the technical details on the problem, such as what voltage & current they can they charge those bus batteries at. Perhaps all they need is an extension like I use here sometimes when I have my Tesla outside and charge it at 12 KW.

I don't know what the AC charger (located inside the bus) specs are, or even if there is one. EV car chargers can normally use any AC input voltage from 85 to 250 VAC.

But perhaps the buses only accepts DCFC. I need more info. to know what the fix would be, if any possible, until the recalled batteries can be replaced.

 

[Babe2201]

They have no outside way to charge?

I would like to know all the technical details on the problem, such as what voltage & current they can they charge those bus batteries at. Perhaps all they need is an extension like I use here sometimes when I have my Tesla outside and charge it at 12 KW.

I don't know what the AC charger (located inside the bus) specs are, or even if there is one. EV car chargers can normally use any AC input voltage from 85 to 250 VAC.

But perhaps the buses only accepts DCFC. I need more info. to know what the fix would be, if any possible, until the recalled batteries can be replaced.

I will help you. Next time they can buy ICE buses and the problem is solved.

 

[Larry N.]

They have no outside way to charge?

Note that the article says the batteries have to be at 41º or above to charge- this is winter in Vermont...

 

[DonTom]

Note that the article says the batteries have to be at 41º or above to charge- this is winter in Vermont...

Should not be an issue in any modern EV. The charging stuff will warm up the battery before the charge starts.

IOW, plug in the charger. The charging does NOT start until the battery is first warmed up by the battery heater. It will take a little longer, depending on how cold it is, but in most cases, we will not notice the difference in charging time.

-Don- Auburn, CA

 

[DonTom]

. Next time they can buy ICE buses and the problem is solved.

Maybe.

Ever hear about fuel phase separation & condensation during cold weather?

-Don- Auburn, CA

 

[Larry N.]

Should not be an issue in any modern EV. The charging stuff will warm up the battery before the charge starts.

Don, read more carefully- they were talking about the specific buses they already have, which ARE temperature limited, regardless of what others are building NOW.

 

[Babe2201]

Maybe.

Ever hear about fuel phase separation & condensation during cold weather?

-Don- Auburn, CA

How common is it? I have yet to experience it or know of anybody that has as well.

 

[DonTom]

they were talking about the specific buses they already have, which ARE temperature limited,

But I did see this part:

"The recall prompted a software update from New Flyer to “decrease the likelihood for fire” that “included only allowing the bus to charge to 75% and to not allow charging when the battery is below 41 degrees,” Clark explained."

Not exactly clear if it has a battery heater or not in above.

But it also says:

“Previously we could charge in any temperature to 100%,” Clark said."

Which makes me believe it does have a battery heater, but they are being asked to not use it.

IMO, they are just being extra careful with such recommendations, extremely unlikely for there to be a problem.

All this reminds me of my Chevy Bolt. Same battery recall issue, and cannot charge above 80% SOC until so many miles. Also advised to not charge inside. But I do anyway and do not expect any issues.

The one 2022 Chevy Bolt that blew up was driven down to below 0 SOC and was instantly recharged to 100% when the battery went into flames.

-Don- Auburn, CA

 

[DonTom]

How common is it? I have yet to experience it or know of anybody that has as well.

Very common when ICE vehicles are left outside for days in very cold weather.

"Phase separation in ethanol-blended fuel is more common during cold weather, primarily due to reduced water solubility in colder temperatures.

Ethanol-blended gasoline (like E10) can hold more water at higher temperatures—approximately 0.5% at 60°F—but this capacity drops significantly as temperature decreases, falling to about 0.3% at 10°F. A sudden temperature drop, such as a 20°F decrease overnight, can push fuel past its saturation point, causing phase separation even if water levels were previously within safe limits.

This phenomenon is especially relevant in winter months when fuel stored underground (warmer) is dispensed into colder vehicle tanks (e.g., below 32°F), creating ideal conditions for separation. While phase separation can occur in any season, cold weather dramatically increases the risk due to the temperature-dependent solubility of water in ethanol."

 

[Babe2201]

Very common when ICE vehicles are left outside for days in very cold weather.

"Phase separation in ethanol-blended fuel is more common during cold weather, primarily due to reduced water solubility in colder temperatures.

Ethanol-blended gasoline (like E10) can hold more water at higher temperatures—approximately 0.5% at 60°F—but this capacity drops significantly as temperature decreases, falling to about 0.3% at 10°F. A sudden temperature drop, such as a 20°F decrease overnight, can push fuel past its saturation point, causing phase separation even if water levels were previously within safe limits.

This phenomenon is especially relevant in winter months when fuel stored underground (warmer) is dispensed into colder vehicle tanks (e.g., below 32°F), creating ideal conditions for separation. While phase separation can occur in any season, cold weather dramatically increases the risk due to the temperature-dependent solubility of water in ethanol."

Like I said I have not had trouble with it and I leave one vehicle undriven quite a bit during the winter as well as power equipment in an unheated garage. I quite often put a little dry gas in my cans as well as vehicles. Seems a much easier fix than what they are dealing with these buses.

 

[DonTom]

Seems a much easier fix than what they are dealing with these buses.

Sure, until the recall is done. I wonder if they will get the new Solid State Batteries--that would be the perfect fix.

I also cannot say I have had any problem with fuel phase separation, but I read about a bunch of commercial trucks that were left outside and NONE of them would start. All the trucks left inside started fine. The company expected sabotage of the gasoline left outside, so had it tested. What was discovered is it was caused by fuel phase separation and no other issues.

I read about this years ago in a motorcycle magazine that was discussing ethanol use in gasoline. I do not remember all the details such as what state or how cold it was, but it can be a problem.

I know some states to NOT put any ethanol in their higher grades of gasoline. In NV, "clear" gasoline (no ethanol) is available. There could be reasons why it is not much of a problem in some cold states.

But it's more of a problem with the gasoline than the vehicle anyway.

Here in CA, they put the ethanol in all grades. Never caused me any issues either. But I can say the same for my EV cars.

-Don- Auburn, CA (snowing here, and somewhat heavy, which is rare).

 

[Gary RV_Wizard]

They have no outside way to charge?

They do, but night time winter temperatures in Vermont are frequently well below a lithium-type battery's minimum charge temperature. So you have to heat the battery first and then charge. But these are busses built by the lowest bidder and likely lack that sort of feature.

 

[DonTom]

. So you have to heat the battery first and then charge. But these are busses built by the lowest bidder and likely lack that sort of feature.

I kinda doubt it. But I cannot say for sure without more info. Battery EV heating/ cooling is nothing new (except in electric motorcycles). My 2018 Tesla as well as my cheap 2022 Chevy Bolt has full battery conditioning (to make it warmer or colder to get to the perfect charging temps regardless of how charged) and my Tesla was purchased here in warm CA (but it is now snowing here in Auburn, which is rare, but 40°F. is not all that cold). All modern EVs (except motorcycles) have a BTMS.

Let me check my Brave AI search:

"Yes, electric buses are equipped with battery thermal management systems (BTMS) that actively warm and cool the battery pack to maintain optimal performance and longevity.

Battery Heating: In cold weather, the BTMS heats the battery to maintain an ideal operating temperature range of 25°C ± 5°C (about 77°F ± 9°F). This is crucial because cold batteries have reduced efficiency and range. The most common method uses a PTC (Positive Temperature Coefficient) electric liquid heater integrated into the coolant circuit. The heated antifreeze then circulates through the battery pack to raise its temperature. Some systems also use integrated electric heating films or high-voltage heaters (e.g., Webasto’s 10-12 kW models).

Battery Cooling: In hot weather, the BTMS cools the battery to prevent overheating, which can degrade battery life and safety. This is typically achieved using a liquid-cooled system with a heat exchanger and a refrigerant-based cooling loop. The system circulates cooled antifreeze through the battery pack to absorb excess heat.

These systems are integrated and often include self-circulation functions to maintain uniform temperature across all battery cells, preventing hotspots. The BTMS is essential for ensuring consistent performance year-round, with some systems also using heat pumps or heat recovery to improve energy efficiency"

Exactly what I would expect in any EV bus made in the last ten or so years, cheap or not. It's more of a necessity, IMO. Unlikely to be an option or available without.

But not so much with motorcycles as not many ride them when extra cold anyway. But my newest motorcycles have it anyway. But I would expect battery temp control in any car or bus made in the last ten years or so.


-Don- Auburn, CA

 

[Derby6]

A guy from CA has solved Vermonts problems. You should get in one of your EV planes, trains, automobiles, or motorcycles and go show them how it’s done.

 

[DonTom]

and go show them how it’s done.

I probably could. I see countless EV problems that are operator error because they did not RTFM!

And especially with EV charging in cold weather.

BTW, Reno can get very cold too during the winter months. Perhaps even AK style cold once in a great while. Record cold for Reno is 17°F BELOW zero (-27.22°C).

-Don- Auburn, CA

 

[Lou Schneider]

The radio related posts have been moved to a new thread.

PL, CTCSS, etc. (was EVs in Vermont)

But these are busses built by the lowest bidder and likely lack that sort of feature. I better explain here how low bid works, as I had to deal with such where I worked in C&C of SF. Let's say it's a new radio system. First step is to have the correct department put the needed specs in...

www.rvforum.net