Greek taxi and traction battery

We had a user, scratesthecabdriver, report traction battery problems in the 2010 Prius in Greek taxi service. I've proposed we start a new thread in the Gen III forum. However, I would not limit it to just our Greek Prius taxi owners but anyone else who might have had a traction battery problem:

This is the NHW11 (2001-03) model forum but I notice yours is the ZVW30 (2010-current) model. We also have a 2010 Prius but a pattern like this is curious:

• Are you typically leaving the car in READY or when waiting for a fare, do you still shutdown the car?
• What sort of terrain (or perhaps a city)?
• What sort of temperatures?
• Any problems with the 12V battery?
• Has anyone tried using a Prius-aware scanner to see what is going on with the traction battery?
• Would anyone have a GPS with data recording (i.e., Garmin nuvi) for route analysis?

I would like to collaborate with you on this problem as we have a 2010 Prius:

• 70,000 km
• typical commuting route
  • ~50 km/day
  • +/- 10m/day
  • ~60 km/hr
• Huntsville, AL
  • river valley with 160m hills
• temperature ranges
  • 15.7C average, 31.7C max, -1.5C min

If you don't mind, perhaps we could restart this thread in the "Gen III" technical forum?

Thanks,
Bob Wilson

 

Sorry, I didn't look before posting but you are bringing something up, the unique characteristics of a Prius in taxi service. I had not thought about the need to keep the car in READY for the heavy, 12V load. Let me suggest we merge our threads, using "report" to make it easier to follow.

I sure wish we could get someone using a ZVW30 (2010 model) Prius in taxi service with a miniVCI to capture some metrics. Hummm, I have a 2010 Prius, a miniVCI, and an AC power inverter on the 12V buss that could drive a resistance load. But I always raise the rear floorboard to run the AC inverter to vent the heat.

Now one of the changes with the 2010 Prius is there is no separate radiator for the inverter. My understanding is the radiator has three cores:

• engine coolant
• A/C condensor
• inverter coolant

If the car is sitting there, the only airflow would be from the radiator fans and they are traditionally driven by the engine coolant temperature. Now I'm wondering if the inverter coolant temperature should also be used to force the fans to operate perhaps with a more aggressive cycle.

We really need metrics and if you are no long in taxi service, perhaps one of our Greek friends might show up. We can then work with them to make a plan to see what is going on.

I've made the assumption taxi service does NOT use the OBD connector so we can still use it to get metrics.

Right off the bat, I'm also wondering if a Prius taxi might also need more 'exhaust ventilation.' If so:

• remove the plastic tray under the rear floor board to help get the heat away from the traction battery
• some sort of 'spring' or shim to give a 1/2 inch (1 cm) gap at the rear floorboard to help vent the traction battery heat
• alternative, remove the rear carpet and make 'vent holes' to help release the heat into the cabin, away from the traction battery

Bob Wilson

 

Perhaps before we 'engineer' an improved traction battery cooling system, we need to get some metrics:

• traction battery temperatures - we need samples during the workday to see if the traction battery temperatures are climbing or riding high
• inverter temperatures - again, we need samples during the workday to see if they are climbing or riding high

We will also need some 'stock' or 'normal' temperatures. For want of better configurations:

• temperatures during a one hour, highway drive
• temperatures from 'cold-start' to 'daily commute'

But all of this depends upon getting cooperation or partnership with a 2010 Prius taxi owner. If no one shows up, the rest does not matter. I'm here to help but I'm not here to become a Prius taxi owner.

Bob Wilson

I'm going to suggest looking at the pressure relief 'valves' located between the body and rear bumper cover. These rubber valves open so when a door is closed it doesn't pop everyone's ears. Duct work could route the hot-air exhaust to one of these valves and force it out.

The NHW11 had a traction battery, hot air exhaust on the side of the body and a traction battery fan to force the hot air out. However, this was also an area where aggressive, car wash and small critters could enter the traction battery area. I've long suspect this was the likely cause of a couple of NHW11 traction battery fires.

But I'm not interested in working on this UNTIL we have some basic engineering metrics about the traction battery temperature profile . . . especially for taxi service.

Bob Wilson

 

The usual killer of a Prius traction battery is heat and charging is exothermic. So we know from the earlier Prius:

• some driving profiles can 'heat pump' the traction battery - a lot of hills at speeds over 70 mph in the NHW11
• ZVW30 does not have an external vent for traction battery heat - the NHW11 does

Now there may be another failure mechanism involved with the taxi service, traction battery failures. But we need at least some temperature measurements to rule out the known killer, heat.

Bob Wilson

 

Are these Prius the taxi service vehicles?

Bob Wilson

 

I started Google searching to see if we can find some Prius taxi service companies:

• Luscious Garage | Blog | Prius Taxi Repair
• GreenTaxi.org | Driving towards a greener future

So it may be the problem is localized to . . . warmer climates with hills . . . hummmm. However, we really need some metrics. Speculation does not work for me.

Bob Wilson