OBD II Data for HVB

[Hybridbear]

Previously the HVB charge limit would be 0 kW when the Abs SOC was 98.4% or higher & would quickly rise from 0 kW to 35 kW once the SOC dropped to 98.4%. Since the recent 15E04 recall reprogramming was done on our car it has begun to behave differently. The HVB charge limit still increases from 0 kW once the SOC drops to 98.4%, but now it doesn't immediately go up to 35 kW. It gradually increases. I left home at 99.62% SOC at 7.138 kWh ETE. At 98.4% the max charge limit went from 0 to 6 kW. At about 98.0% the max charge limit is up to 10 kW. At 97.0% the max charge limit is up to about 20 kW. When I arrived at work this morning the SOC showed 96.24% and the max charge limit was up to 30 kW. Has anyone else seen this?

Edited September 10, 2015 at 02:03 PM by Hybridbear

[Hybridbear]

The max charge limit didn't reach 35 kW until the absolute SOC dropped below about 95.05%.

Edited September 15, 2015 at 01:07 PM by Hybridbear

[stevedebi]

Previously the HVB charge limit would be 0 kW when the Abs SOC was 98.4% or higher & would quickly rise from 0 kW to 35 kW once the SOC dropped to 98.4%. Since the recent 15E04 recall reprogramming was done on our car it has begun to behave differently. The HVB charge limit still increases from 0 kW once the SOC drops to 98.4%, but now it doesn't immediately go up to 35 kW. It gradually increases. I left home at 99.62% SOC at 7.138 kWh ETE. At 98.4% the max charge limit went from 0 to 6 kW. At about 98.0% the max charge limit is up to 10 kW. At 97.0% the max charge limit is up to about 20 kW. When I arrived at work this morning the SOC showed 96.24% and the max charge limit was up to 30 kW. Has anyone else seen this?

 

HB,

Probably just adjusting the algorithm. It sounds like Ford did what Honda did on their Civic Hybrid recall - they changed the way the batteries were charged to make them last longer.

 

Better than what Honda did; their update caused MPG to plummet (but saved the batteries from premature failure). Owners were not amused.

Edited September 11, 2015 at 05:03 PM by stevedebi

[rbort]

Also, slamming so much charge to full batteries is going to take the voltage over the limit they like, and force the engine to start.  Maybe by limiting the charge level now you can test the theory for us and see if the engine will not start if using hill decent or L while the battery is full or very close to it.

 

-=>Raja.

[Hybridbear]

Today the charge limit reached 35 kW at 95.05% abs SOC.

Edited September 16, 2015 at 06:29 PM by Hybridbear

[Hybridbear]

Today I had more strange behavior. I left home with the abs SOC showing 99.31%. It was down to about 98.2% when it was time for my first stop sign. The HVB charge limit was 20 kW to start & gradually dropped down to 0 kW. It didn't drop all the way to 0 kW until the HVB SOC reached 98.55%. Previously the HVB charge limit would drop to 0 kW at 98.4% exactly. The last little bit of my stop was with just the brake pads. I pulled away from the stop sign & the HVB charge limit stayed at 0. It was down to about 95.5% when I was approaching the second stop sign. From about a block away I took my foot off the accelerator. The car rolled along with no regen. I lightly pressed on the brake, again no regen. The car was stuck at 0 kW charge limit. I shifted to N & back to D. Once I shifted back to D the charge limit started climbing & I was able to stop with regen braking.

 

I'm going to be taking a drive with a Ford engineer on the 30th to show him the issues with regen braking while turning. We'll see what happens then...

[Hybridbear]

This past week I had to use gas for the first time in over a month. This allowed me to run the HVB all the way down to hybrid mode. I arrived home with 1.338 kWh showing as the ETE. I used up the final ~2 kWh (from ETE 3.4 kWh) during the last few miles of my drive. I noticed no increase in mV of cell voltage variation at the low SOC. When I parked at home the car reported only 3-4 mV variation when the HVB was not under a load other than the electronics to power the car. I was glad to see that voltage variation was not significantly increased in this scenario.

[larryh]

The following plot shows degradation of the HVB over the three years I have owned the car.  I recorded the HVB temperature and the Energy Capacity of the HVB each day for the past two years--I don't have measurements for the first year.   There wasn't much degradation during the first year.  Each marker represents one of those measurements.  When new, the maximum capacity of the HVB was 7.2 kWh at temperatures above 70 F.  The car will not let you discharge the HVB below 1.0 kWh to prevent damaging it.  If you fully discharge the HVB, it will no longer accept a charge.  In addition, the car does not generally charge the HVB to 100% SOC--it usually charges to about 97%-98%.  So the maximum energy you can get out of the HVB when it is new is about 7.2 kWh - 1.0 kWh - 0.2 kWh = 6.0 kWh.  

 

As the chart indicates, degradation is greater with decreasing temperature.  So in the winter, HVB degradation has a much greater impact than in the summer.

 

The blue markers represent measurements made during 2014.  At a HVB temperature of 85 F, the capacity of the battery was about 7.1 kWh.  During 2015, the red markers, it was about 6.95 kWh.  And for 2016, the green markers, it was about 6.8 kWh.  The total degradation at 85 F is about (7.1 - 6.8)/6.0 = 5% after three years.  [Note since I don't have measurements for the first year, I'm not sure if 7.1 is the correct number to use.  The measured capacity could well have been 7.2 kWh during the first year, in which case, degradation would be 7%].

 

At a HVB temperature of 50 F, the battery capacity was about 7.0 kWh during the first year.  After three years, it was about 6.4 kWh at this temperature.  The degradation during the winter is about (7.0-6.4)/6.0 = 10 [or again, since I don't have measurements for the first year, it may be as high as 12%].

 

There is insufficient data for temperatures below 40 F to provide accurate measurements.  

 

I currently have 35,000 total and 25,000 EV miles on the car.  I charge about once a day using a 240 V charger set to charge at 3:00 am.  My commute is 16 miles during the week so I only fully discharge the HVB during my weekend drives.  I live in Minnesota.

 

 

Edited May 26, 2016 at 11:27 PM by larryh

[larryh]

The chart below shows the annual degradation of an older design Lithium-Ion battery at various SOC and temperatures.  The battery was maintained at the specified temperature and SOC for a year and then the degradation was measured.  Degradation  occurs continuously in a Lithium-Ion battery, even when it is not being used.  Undesirable chemical reactions are always taking place in the battery that degrade its capacity.  The rate of these undesirable chemical reactions are a function of temperature and SOC.  The maximum rate of degradation occurs at the top right at high temperatures and high SOC.  The minimum rate of degradation occurs at the bottom left at low temperatures and low SOC.  The HVB in the Energi should have significantly less degradation under the same conditions as the battery in the chart--perhaps at 1/4 the rate indicated in the chart.   But as with the older design battery, degradation increases with increasing SOC and temperature.  

 

The white bars illustrate where the HVB in my car spends most of its time during the summer.  The car charges from about 3:00 am to 4:30 am in the morning.  I then leave for work at about 5:15 am.  During this time, the car is at 100% SOC for less than an hour a day.  The top bar is where the battery operates during this short period of time:  around 90 F and 100% SOC.  HVB degradation occurs during this period at a rather high rate, but only for a short period of time.  

 

I leave the car parked at work for about 9 hours in the shade of a tree.  During this time the SOC is around 66% and the HVB temperature is between 80 F and 100 F.  The middle bar indicates the state of the battery during this time.  HVB degradation now occurs at a more moderate rate.

 

When I arrive home, I plug in the charger, but have value charge profiles set up so the car does not charge until 3:00 am in the morning.  The car sits in the garage for the rest of the day with the HVB temperature between 75 F and 100 F at about 30% SOC.  For most of the day, degradation now occurs at a much slower rate.

 

During the spring, fall, and winter, the HVB temperatures are lower--the horizontal bars move to the left.  Degradation now occurs at a significantly reduced rates vs. during the summer.  In fact, during the winter, the HVB temperature stays below 50 F most of the time.  The HVB battery spends practically all its time during the winter in the blue region with the slowest degradation rate.

 

Now consider someone with a long commute that charges at home and at work.  However, instead of delaying charging, they charge immediately when they get to work and when they get home.  Since they have a longer commute than I, the temperature of their HVB is going to be warmer.  Since they charge immediately, the SOC of the battery is going to be at 100% for most of the day.  During the summer, their battery is going to be spending most of its time in the salmon colored region at the upper right of the chart with maximum rate of degradation.  Their battery is going to degrade four to five times faster than mine.  It would be much better if someone with a long commute delayed charging until right before leaving for work or to return home rather than charging immediately upon arrival at work or home.   If they did that, the HVB would spend most of its time at the far bottom right corner of the chart where degradation occurs at maybe one-half to one-third the rate it occurs vs. charging immediately.

 

There are other factors that affect battery degradation (such as the number of charge/discharge cycles), but temperature and SOC are the primary factors that impact battery degradation.  

 

 

Edited June 4, 2016 at 07:24 PM by larryh

[Automate]

Nice,  what is the source for the chart?

[larryh]

http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

 

Actually, the degradation at top right of the chart should be far worse than shown.  40% loss occurred in three months rather than one year for 100% SOC and 140 F.   However, the HVB in the car should never reach 140 F.  The maximum I have observed is 113 F.  But if you live the South where temperatures reach 120 F, the battery is going to be at least that temperature.  You could always skip charging the battery (at least not to 100%) and use the ICE instead if it gets that warm.  

Edited June 4, 2016 at 09:00 PM by larryh

[larryh]

The following link provides information on optimized charging strategies to prolong battery life:  http://www.nrel.gov/docs/fy14osti/62813.pdf

 

They considered six different strategies for charging at night.  The battery in this study has a larger capacity battery than the Energi's HVB.   Note that the Energi HVB can only accept a maximum charge power of 3.3 kWh, i.e. half the full level 2 charging power.  For the battery in this study, the battery can be charged at the full Level 2 power of 6.6 kW.  

 

1.  Charge on plug-in:  charge immediately on plug-in at full level 2 power of 6.6 kW.  Battery life was 5 years.

2.  Slow charge:  charge at a slow, constant rate for the entire night.  Battery life was 6.8 years.

3.  8 hour charge: charge at a slow rate for the last 8 hours. Battery life was 7.2 years.

4.  Late fast charge: charge at 18 kW during the last hour.  Battery life was 6.8 years.

5.  Late 6.6 kW charge: charge at full level 2 power of 6.6 kW waiting until the last possible moment.  Battery life was 7.9 years.

6.  Delayed Charge: charge at full level 2 power of 6.6 kW starting at 12:00 am.  Battery life was 6.3 years.

 

The best strategy was 5:  Charge at full level 2 power waiting until the last possible moment.  Predictably, the worst strategy was 1:  Charge at full level 2 power immediately on plug-in.  The difference in battery life between the two strategies was 2.9 years (very significant).  Strategy 5 is basically what I am doing.    

 

Note that 1, 5, and 6 explore when is the best time to start charging at full level 2 power of 6.6 kW.  The results clearly demonstrate that delaying charging until the last possible time provides a significant increase in battery longevity:  5 years for charging on plug-in, 6.3 years for starting at midnight, and 7.9 years for waiting until the last possible moment.

 

2, 3, 4, and 5 explore what is the best rate at which to charge the HVB, delaying charging at that rate until the last possible moment.  You want to charge it had a relatively fast rate (5), but not too fast (4).  Also, you don't want to charge it too slowly (2) and (3).  

 

Basically, you want to delay charging as long as possible and then charge at the maximum charge rate of 3.3 kW allowed by the Energi's internal charger for the HVB.

Edited June 5, 2016 at 12:01 AM by larryh

[larryh]

Another paper that corroborates the one in the previous link can be found here:  http://ecal.berkeley.edu/pubs/JPS_ChgPatternOpt_Preprint.pdf.

 

"Comparing different solutions ... indicates that to effectively minimize battery degradation and energy costs, one should ideally charge a PHEV rapidly, off-peak, and shortly before the onset of road travel".

 

Figure 7 in that paper provides a battery degradation map showing battery degradation for various charge/discharge rates at room temperature.  Degradation increases with increasing charge rate, and decreases with increasing discharge rates.  The battery degrades orders of magnitude faster during charging (using the charger or via regen) than during discharging (i.e. powering the car) or storage.  In addition, degradation is slightly greater during storage than while discharging the battery (i.e. powering the car).  When charging at a given charge rate, degradation is significantly greater at both high and low SOC.  That is one reason the charger tapers charging when the SOC approaches 100%.  

 

Since degradation rates are higher with increasing charge rate, one would think it would be better to charge at a slower rate than a faster one.  However:

 

"Figure 12 shows that the optimal charging rate ... is close the maximum rate of 1C. At the first glance, this seems counterintuitive, because from the battery degradation map (shown in Figure 7) we see that the battery degradation rate is higher at higher charge rates.  However, it is also evident that by increasing the charge rate we decrease the charging duration.  Thus, the high-rate battery degradation process due to fast charging takes place for a shorter period of time. Hence, the resultant damage can be smaller if reducing the total battery degradation due to reducing the charging duration dominates the increase of degradation due to fast charging. The obtained optimal results indicate that this condition holds true, at least within the range of 0-1C charging, according to the employed battery model."

 

The charge rate for the level 1 charger is about 0.15 C and for the Level 2 Charger is about 0.4 C.  Both are between 0 and 1C.  Hence charging using a Level 2 Charger degrades the battery less than using a Level 1 Charger.  For the battery in their study, the optimal charge rate is 1C, which is approximately the full Level 2 charge rate of 6.6 kW. 

 

You want to delay charging until the last possible moment and charge the HVB with a Level 2 charger.  

 

One additional observation about delaying charging until the last possible moment, is that if you charge earlier, the battery will begin to cool off before you leave.  It is loosing energy.  So by delaying charging, you maximize the amount of energy available for your commute.  

Edited June 5, 2016 at 12:58 AM by larryh

[bdginmo]

I probably missed it, but I didn't see how they defined "battery life". Is it when the capacity drops below a certain threshold or is it when it literally dies and becomes totally nonfunctional?

Edited June 6, 2016 at 01:41 AM by bdginmo

[rbort]

But what about if you charge at the latest possible moment and not let the battery cool?  In the winter it would be advantageous as you want a warmer battery to give you a little bit more power output as well as a warmer cabin from charging.  In the summer it might work against you as the battery temp would be initially higher and rise even higher while draining it with the heat of the the day.

 

-=>Raja.

[rbort]

Also, you're not doing #5 because that's a 6.6kwh charge, you're only doing 1/2 of that.  So the lifespan should be somewhere between 7.9 and 7.2 years, perhaps maybe 7.5 years.  Life also depends on how often you charge and how many times per day.  Less is more life in that case.

 

-=>Raja.

Edited June 6, 2016 at 05:55 AM by rbort

[larryh]

In the papers in the previous post, the end of life of the battery was declared when either the capacity fell below 80% of the original capacity, or power fell below 90% of the original power. However, the papers assumed a different battery chemistry than the Energi’s HVB and also they assumed a 30 kWh battery (4x the size of the Energi’s). Further they assumed the battery is charged only at night and made simplifying assumptions how the battery was discharged during the day. They took into account degradation of the battery due to SOC, Temperature, and Cycling effects. You can’t directly apply those results to the Energi’s HVB.

 

The most important conclusion that you can draw from those reports is that you want to delay charging as long as possible prior to your morning commute. That agrees with the chart in my previous post showing the rate of degradation vs temperature and SOC. You don’t want to keep the HVB at 100% SOC any longer than is necessary. They did not investigate the optimal strategy for people that also charge during the day.

[larryh]

There is no way for us to determine the optimal charge profile for charging the Energi’s HVB. For the battery under investigation in the papers, the optimal charge profile was not a constant rate, but a gradually increasing charge rate maxing out at about 5 kW ending just before the start of the morning commute. If we restrict charging to constant rates, then the optimal constant charge rate is 6.6 kW. However the battery life difference between these two profiles was only a couple of days (below the level of uncertainty of their models). So either one is a good strategy.

 

The Energi’s HVB is a different size and uses a different chemistry versus the one in the papers. So the optimal charge rate for the Energi’s HVB is unknown. The only thing we can be certain of is that delaying charging until the last possible moment is better than charging sooner. MyFord Mobile allows us to enter GO Times and the Time of Day electric rates. Ford should also use this information to minimize HVB degradation. The user should be able to plug in the car and then the car could determine the optimal charge profile to minimize electricity cost and simultaneously minimize HVB degradation, ensuring the car is fully charged by the next GO time.

 

The battery is very expensive. Each time you charge the HVB, it degrades a little more. There is a cost associated with this degradation. Eventually, you are going to have to replace the battery when it degrades too much. I would rather pay a little more for electricity if it saves me from having to replace the battery. It may be better to delay charging to a time when electric rates are more expensive if it significantly reduces degradation of the HVB. It may cost me an extra $1 to charge at the higher rates, but the additional degradation caused by charging in lower cost electric rate windows may be $10. The user should be able to plug in the car at any time and the car will take care of the rest to minimize my overall cost. If properly implemented, this could significantly increase the HVB lifetime by years.

Edited June 6, 2016 at 02:06 PM by larryh

[murphy]

Unfortunately they don't want you to drive the car for years.  They want you to buy a new one sooner rather than later.

[rbort]

The most important conclusion that you can draw from those reports is that you want to delay charging as long as possible prior to your morning commute. That agrees with the chart in my previous post showing the rate of degradation vs temperature and SOC. You don’t want to keep the HVB at 100% SOC any longer than is necessary.

 

I totally agree Larry, though as far as the difference between plugging in at midnight to be ready at 6am with 120v vs plugging in at 4am to be ready at 6am with 240v, I'm not quite sure of the difference.  In both cases you reach 100% around 6am, though you spend more time getting there with 120v.  

 

I have to some extent split up my charging in separate sessions instead of doing one fell swoop to 100% when necessary if possible.  In other words I came home last night with an empty battery, I just charged it a little bit to 10% off the bottom and unplugged it.  Today I'll charge it to 50-60% and leave it.  And if/when I need it I'll charge it to 100% from the middle instead of from 10%.  I find that longer charging causes the fan inside the car to start racing, and heat to build up more, so shorter sessions seems to be better than longer ones keeping the fan running slow.  This happens much quicker with 240v (fan starts racing) than with 120v due to faster charging.  Sometimes I may not even need to go to 100%, because 50-60% may take me to the grocery store and I could charge there while shopping and come back home with a relatively same level of charge even after the trip there and back.

 

The exception is when I'm on the road and need 100% back, in that case I crack the windows and let it charge up while I'm having lunch or dinner at some restaurant.

 

-=>Raja.

Edited June 6, 2016 at 03:15 PM by rbort

[flyingcheesehead]

Interesting. I'm pretty much the bad case, I plug the car into L1 both at work and at home because I can't make the full commute on a single charge unless the conditions are *just* right and I really baby it. (I've only managed once in a year and a half.) But, I'm now firmly addicted to electric driving and I hate when the ICE in my Energi kicks on! 

 

I also don't have a time-of-use electrical plan, so I haven't set up a value charge profile, nor do I bother with waiting to plug the car in until I need to. Also, sometimes I drive it on weekends and sometimes I don't, so when I plug it in Friday night at home it'll charge up and stay at 100% all weekend. Luckily, I live in Wisconsin so the battery also never gets particularly hot.

 

I know most BEV drivers don't charge to 100% to keep degradation down, but that isn't really an easy option for us PHEV drivers - Not enough capacity! Armed with this latest information, maybe I'll put in a value charge profile so it doesn't finish charging until closer to the time I leave in the morning. I'll also be putting a 125A subpanel and some 14-50 outlets in my garage for L2 soon, at work I'll only ever have access to L1. Hopefully the lower amount of time spent at 100% on L1, and the slower (and thus cooler) charge does help somewhat.

[larryh]

The following plot shows battery degradation at room temperature of the Li-ion battery in the papers of the previous posts as a function of SOC.  The Blue line is the degradation that occurs when the battery is not being charged in 10e-8 Ohms/second.  The red line is the degradation rate for a Level 1 Charger and the green line is the degradation rate for a Level 2 Charger.   Degradation increases rapidly with increasing power applied to charge the battery.  Degradation decreases with increasing power discharged by the battery to at least several kW and then begins increasing again very rapidly.  

 

So charging the battery increases the battery degradation rate above and beyond the normal degradation rate that occurs while the car is off.  In this case, the Level 1 Charger increases the degradation rate by 0.22 x 10-e8 ohm/s and the Level 2 Charger increases the rate by 0.63 x 10e-8 ohm/s.  The total increase in resistance due to charging the battery with a Level 1 Charger for six hours is then 0.48 mOhms.  The total increase in resistance due to charging the battery with a Level 2 Charger for 2 hours is 0.45 mOhms, i.e. slightly less.  So in this case, the additional degradation caused by charging the battery is less using the Level 2 Charger.  Even though degradation occurs at a much higher rate with the Level 2 Charger, we are charging the car for much less time, so total degradation is less.  We have no way of determining the actual difference for the HVB in the Energi.  So it is entirely possible that using a Level 2 Charger will result in less battery degradation, provided you only charge the battery with it just before you leave.  If you don't want to go to the extra trouble to only charge the HVB right before you leave, you would be better off with the Level 1 Charger--it can't charge the car as fast so the average daily SOC will be lower vs. the Level 2 Charger resulting in less degradation.  

 

Note that according to the chart below, degradation occurs 8% faster when the battery is at 60% vs 30% SOC.  So it could be advantageous to leave it at a lower SOC than 60%.  Also, the SOC reported by the car is not the true SOC of the HVB.  The actual SOC is higher.  When the car says the SOC is 0%, it is really about 20%.  

 

I wouldn't worry about the fans.  The vast majority of the heat generated is from the car's internal charger itself, not the battery.  When attached to a Level 1 charger, 20% of the energy is lost as heat by the charger.  For the Level 2 charger, 10% of the energy is lost.  The HVB itself only converts about 3% of the energy to heat.  The fans running a high speed is a good thing.  It will help cool down the HVB quicker.  

 

 

Edited June 6, 2016 at 11:43 PM by larryh

[larryh]

Interesting. I'm pretty much the bad case, I plug the car into L1 both at work and at home because I can't make the full commute on a single charge unless the conditions are *just* right and I really baby it. (I've only managed once in a year and a half.) But, I'm now firmly addicted to electric driving and I hate when the ICE in my Energi kicks on! 

 

I also don't have a time-of-use electrical plan, so I haven't set up a value charge profile, nor do I bother with waiting to plug the car in until I need to. Also, sometimes I drive it on weekends and sometimes I don't, so when I plug it in Friday night at home it'll charge up and stay at 100% all weekend. Luckily, I live in Wisconsin so the battery also never gets particularly hot.

 

I know most BEV drivers don't charge to 100% to keep degradation down, but that isn't really an easy option for us PHEV drivers - Not enough capacity! Armed with this latest information, maybe I'll put in a value charge profile so it doesn't finish charging until closer to the time I leave in the morning. I'll also be putting a 125A subpanel and some 14-50 outlets in my garage for L2 soon, at work I'll only ever have access to L1. Hopefully the lower amount of time spent at 100% on L1, and the slower (and thus cooler) charge does help somewhat.

 

You can also set the value charge windows to indicate a high electric rate to avoid charging right after you plug in at work (provided you at at work long enough that you can delay charging).  My first priority though would be to make sure that the car is not in the hot sun.  The can easily cause the HVB temperature to rise above 100 F.  

[bdginmo]

Interesting...so the end of life was 80% original capacity or 90% original power. I realize that's an apples-to-oranges comparison since the chemistry and size weren't the same, but that's actually encouraging. I don't think very many of us on here will be terribly upset if we can go 6+ years and still have 80% capacity left. That seems like an acceptable amount of degradation to me. 

[rbort]

Larry:

 

 

 

The total increase in resistance due to charging the battery with a Level 1 Charger for six hours is then 0.48 mOhms.  The total increase in resistance due to charging the battery with a Level 2 Charger for 2 hours is 0.45 mOhms, i.e. slightly less.

 

How are you coming up with these numbers?  I tried to follow your math the 0.22 and 0.63 make sense but I thought x 10e-8 means divided by 10 with 8 zeros.  How is 22 going to change to 48 or 63 to 45?

 

Also, if the battery is 7600kw, the L2 charge rate is 3300kw, so 3300/7600 means 0.43c not 0.4c.

 

And, we know that L1 charges at 3x slower than L2, so while the charger consumes about 1340w it only puts into the battery 20% less due to losses so say 1072/7600 = 0.14c so the charge rates are a little bit more biased to 120v's favor than the numbers you listed above.  If you calculate with those numbers 120v might be slightly better instead of slightly worse.  Makes sense anyways (charge rate of 0.14c to 0.43c) as 120v charges 3 times slower.  You can time it and see that for every 1% it takes about 1 minute 12 seconds on L2, and 3 minutes 39 seconds on L1 if I recall correctly, I've actually used a stopwatch to check.

 

-=>Raja.

Edited June 7, 2016 at 03:17 AM by rbort