Hybrid battery check

[Gliderpilot]

Without resulting to renting Techstream, (I don't have an op sys that it will run on) is there a way to check the cell pair voltages, will Torque pro do it with the associated PID for the Prius? I ask because my fuel consumption has gone up slightly and I'm not getting the regen I expect.

[steveledzep]

It's probably to do with the cooler temperatures.  My RX drops from 35mpg in the summer to 30mpg ish in the winter.

[Rutlandlex]

I was getting 31mpg in the summer and 26-27 in the winter so what sort of figures are you getting Gliderpilot?  Does your Battery ever go green on the power meter because if so then that would suggest that it is healthy enough?

[Zotto]

A procedure to test HV Battery is present in Hybrid Assistant app.

[Gliderpilot]

4 minutes ago, Zotto said:

A procedure to test HV battery is present in Hybrid Assistant app.

I've tried that with not a lot of success as I get figures from 1.5 Ah to 6 Ah, but no where near the 9.5 of a new Battery. I'm getting an average of 28 to 29 mpg at the moment and the Battery indicator is always somewhere around the 8 bar level and occasionally drops to 2 bars when at low speeds for a prolonged time.

[Zotto]

With Techstream you could probably have more info about single cells conditions, it could be you need some kind of rebalancing or change  some cells.

[pedrofromredro]

 

7 hours ago, Gliderpilot said:

I've tried that with not a lot of success as I get figures from 1.5 Ah to 6 Ah, but no where near the 9.5 of a new battery. I'm getting an average of 28 to 29 mpg at the moment and the battery indicator is always somewhere around the 8 bar level and occasionally drops to 2 bars when at low speeds for a prolonged time.

That is high mpg we only get around 19 mpg 

[Britprius]

7 hours ago, Gliderpilot said:

I've tried that with not a lot of success as I get figures from 1.5 Ah to 6 Ah, but no where near the 9.5 of a new battery. I'm getting an average of 28 to 29 mpg at the moment and the battery indicator is always somewhere around the 8 bar level and occasionally drops to 2 bars when at low speeds for a prolonged time.

The only figures available even in Techstream are the voltage of module pairs. For 2x6 cell modules around 15 volts depending on the level of charge, and there internal resistance (typically around 0.023 milli ohms). For 2x8 cell modules the voltage is around 19 volts, and the internal resistance will be around 0.025 milli ohms. The cell capacity of both types is 6.5 amp hours, but not all of this capacity is usable in the vehicle.

Single cell information is not available nor single module information. This is because all the modules are connected in series, and there are only Battery sense connecting wires on every second module (20 sensing wires for 40 modules or less for vehicles with 8 cell modules).

People wrongly call the Battery modules cells, but it takes 6 cells connected in series to make up a module of 7.2 volts or 8 cells for 9.6 volt modules(1.2 volts per cell) in the same way it takes 6 cells to make up a 12 volt car Battery (2 volts per cell). The The 8 cell modules have metal cased cells against the 6 cell plastic variety used in the great majority of Toyota/Lexus vehicles. It is possible to measure individual cell voltages with a volt meter on the 9.6 volt 8 cell modules, but the individual cell terminals on the 7.2 volt modules are not available. 

John 

[Rutlandlex]

28 minutes ago, pedrofromredro said:

 

That is high mpg we only get around 19 mpg 

Holy sh**!  How do you get it so low?

[Herbie]

34 minutes ago, pedrofromredro said:

 

That is high mpg we only get around 19 mpg 

Wow, you've either got a VERY heavy right foot or there's something wrong there - even the petrol RX300s aren't that heavy on fuel  

[pedrofromredro]

17 minutes ago, Herbie said:

Wow, you've either got a VERY heavy right foot or there's something wrong there - even the petrol RX300s aren't that heavy on fuel  

It's mostly the wife that drives the car.it only goes short distances few miles a day that's what I'm thinking it is well that's what I'm hoping it is 

 

[Gliderpilot]

Short distances are a killer to the older 400h cars. The hybrid algorithm doesn't cut in until the engine is hot and that takes a mile or so. Not the case with our new Yaris where if you are driving around 30 mph with a light right foot you can use EV mode much sooner. Keeping the 400h in EV mode is very difficult, and can only be done when the engine is hot. That's what I've found after 5 years of ownership. As to the chap who only gets 19 mpg, I get that towing a 1700 kg caravan so there must be other underlying problems with the drive train or hybrid Battery.

[vadre]

19mpg. That is not good. Have you tried the ISC reset procedure?

https://us.lexusownersclub.com/forums/topic/58930-isc-learning-procedure-without-lexus-diagnostic-tester/

 

 

[pedrofromredro]

9 hours ago, Gliderpilot said:

Short distances are a killer to the older 400h cars. The hybrid algorithm doesn't cut in until the engine is hot and that takes a mile or so. Not the case with our new Yaris where if you are driving around 30 mph with a light right foot you can use EV mode much sooner. Keeping the 400h in EV mode is very difficult, and can only be done when the engine is hot. That's what I've found after 5 years of ownership. As to the chap who only gets 19 mpg, I get that towing a 1700 kg caravan so there must be other underlying problems with the drive train or hybrid battery.

Going back to your post glider pilot I did put techstream on are RX back a while ago and checked the Battery and got a screen shot of it.

[pedrofromredro]

1 hour ago, vadre said:

19mpg. That is not good. Have you tried the ISC reset procedure?

https://us.lexusownersclub.com/forums/topic/58930-isc-learning-procedure-without-lexus-diagnostic-tester/

 

 

Nope haven’t tried doing it but have read about it.

[Zotto]

Blocks 2,3,4 and 13 seem to have V values a bit lower than others, may be the rebalancing procedure could help.

Unfortunately it requires much time and a dedicated balancing equipment.

[welland]

On 1/24/2019 at 1:44 PM, Rutlandlex said:

I was getting 31mpg in the summer and 26-27 in the winter so what sort of figures are you getting Gliderpilot?  Does your battery ever go green on the power meter because if so then that would suggest that it is healthy enough?

Exactly which power meter display are you referring to?  Do you mean the one on the centre console touch screen (which also does satnav)?  That's what I have and it is always green - I didn't know that it could change to different colours to change its meaning.  

[GSLV6]

It's perfectly normal for mpg to drop in colder conditions and it has nothing to do with the hybrid system.

Colder air is denser air, so more of it gets taken in.  As your cars all have mass flow and density sensors, they pick up on this and to maintain a balanced stoichiometric mixture (A/F ratio to you luddites), the ECU ensures that the mapping is richened up to balance the total air mass.  This has two main effects:

1) greater power output (bigger bang = more power and torque);

2) worse mpg (you use more fuel per engine revolution).

There is a third contributing factor...some or many of us will leave our cars idling to warm them up and demist and idling on cold running fuelling will gobble petrol.

I'm currently achieving 27mpg combined (short trips plus hills) which is 10% down on summer figures.  10% drop in mpg isn't that untypical.

[Rutlandlex]

On 1/27/2019 at 6:30 PM, welland said:

Exactly which power meter display are you referring to?  Do you mean the one on the centre console touch screen (which also does satnav)?  That's what I have and it is always green - I didn't know that it could change to different colours to change its meaning.  

See image below.  Do you ever run your Battery low by driving on electric only because if you do it should go blue until it gets down to 2 bars then it will turn purple and the engine may kick in.

6 hours ago, GSLV6 said:

It's perfectly normal for mpg to drop in colder conditions and it has nothing to do with the hybrid system.

Colder air is denser air, so more of it gets taken in.  As your cars all have mass flow and density sensors, they pick up on this and to maintain a balanced stoichiometric mixture (A/F ratio to you luddites), the ECU ensures that the mapping is richened up to balance the total air mass.  This has two main effects:

1) greater power output (bigger bang = more power and torque);

2) worse mpg (you use more fuel per engine revolution).

There is a third contributing factor...some or many of us will leave our cars idling to warm them up and demist and idling on cold running fuelling will gobble petrol.

I'm currently achieving 27mpg combined (short trips plus hills) which is 10% down on summer figures.  10% drop in mpg isn't that untypical.

Hybrids are affected even more than normal cars because you are comparing the summer when the engine will shut off readily even if not warm with winter when it is running a lot of the time.  There are other variables particularly heater settings that affect when and how long the engine runs.

On a normal car the engine runs all of the time anyway save for stop/start technology so the difference is smaller.

[GSLV6]

I remember keeping track and comparing my E46 6 pot  beemer and my GS300 winter and summer figures and they were very similar percentage-wise to the drop in efficiency of our RX....about 10% for each so I haven't seen any marked difference between the hybrid and non-hybrid.  Mind you, a lot depends on the topography.  As I live in an area where to get anywhere, hills and twisty country roads are involved, then there's bound to be less difference anyway because the engine is used most of the time, hot or cold.  Hybrid savings only really apply when creeping along in town or on low average speed flat runs which we very rarely encounter day to day here.  Also, heated seats aren't much used by us, perhaps for a few minutes whilst the engine warms up and cabin temperature climbs.  After that we usually switch them down or off. 

 

[Farnham Dave]

On 1/24/2019 at 1:16 PM, Gliderpilot said:

Without resulting to renting Techstream, (I don't have an op sys that it will run on) is there a way to check the cell pair voltages, will Torque pro do it with the associated PID for the Prius? I ask because my fuel consumption has gone up slightly and I'm not getting the regen I expect.

Yes, torque pro will do it. You have to set it up... I've just changed phones, so have lost my previous setup (hoping it's in my backup)... There's also a spreadsheet somewhere on the internet.

[Mihanicos]

When new, my car used to do 43 miles to the gallon.

As the years went by, this figure kept going down and by coincidence when a maintenance item was carried out according to the maintenance service schedule. eventually it dropped to 40.4 miles to the gallon and two months ago, I used to get " check VGRS system " and the car would not start on the first time.

I used the techstream and no trouble codes were present and the VGRS system was ok. However there was a message that the 12v Battery was low with only 10 volts.

I charged the Battery to the full and the car started without any codes. It run for a few minutes and the engine stopped, normal behaviour. After a few minutes , the engine started again and it should not have done since the car was stationary in the garage. This only meant that the 12v Battery needed to be charged.

A check on the Battery revealed 10 volts.

I had the Battery checked and it was not up to specification. I put a new 80Ah ordinary Battery and not the original Panasonic and the car now does 42.5 miles to the gallon.

I was convinced that the hybrid Battery was in need of maintenance and I was planning to do so in a couple of months when the weather improves. I never thought that a bad 12v Battery would make so much difference in the fuel economy.

 

Chris.

[GSLV6]

Excellent point.  Yes, once the deep cycle Battery runs down and the cells aren't able to take a recharge then the main engine will have to run more continuously in order to try and charge the Battery.  Once it gets down below a certain voltage I understand that it will throw a fault code and may affect some other functions too (not least of which is non-starting!).  It is meant to be replaced with a deep cycle sealed Battery (VGR/gelmat type) or sealed L/A equivalent.  Normal automotive car batteries aren't designed to be continuously be deep discharged and may not last long under that duty, although they'll get you out of a hole short term.  

[Farnham Dave]

On 1/24/2019 at 10:54 PM, pedrofromredro said:

It's mostly the wife that drives the car.it only goes short distances few miles a day that's what I'm thinking it is well that's what I'm hoping it is 

 

I do a lot of short trips in 12 year old 400h, and I'm not the most gentle when it comes to the horses, but even I get 21-22 (which is still better than my previous car... A 2.4 litre Hyundai at 18-19). I'd get it checked.

[Farnham Dave]

On 1/24/2019 at 11:12 PM, Gliderpilot said:

Short distances are a killer to the older 400h cars. The hybrid algorithm doesn't cut in until the engine is hot and that takes a mile or so. Not the case with our new Yaris where if you are driving around 30 mph with a light right foot you can use EV mode much sooner. Keeping the 400h in EV mode is very difficult, and can only be done when the engine is hot. That's what I've found after 5 years of ownership. As to the chap who only gets 19 mpg, I get that towing a 1700 kg caravan so there must be other underlying problems with the drive train or hybrid battery.

That's a good point about waiting for the engine to warm up... My fuel consumption seems worse as the weather is cooling. Also, of course, batteries are less efficient in the cold.