LS Hybrid: How a poor 12v battery might actually affect your fuel economy/performance
#1
Intermediate
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LS Hybrid: How a poor 12v battery might actually affect your fuel economy/performance
Just got back from the dealer to change the 12v battery; adding my previous purchased wallet key fob and I already busted the 1k at this dealer lol.
Although the dealer wouldn't confirm the manufacturing date on those Panasonic battery it seems pretty easy to figure. There is a white inscription just on top of the battery in the following format: dd/mm/yy
I've been monitoring the traction battery for the last month and it occurred to me that it was draining pretty fast, being only 2 bar a few time. I already knew that my 12v battery was still the original (more than 7 year old) because I always had problem starting the car if it was left to ACC position for about a min. But I never ever failed to start or even need to jump start it (sometime it took more than a min of trying but I was always successful). So I made the assumption that the traction battery was actually giving some juice to the 12v battery in order to help the car start. I also saw that this process was draining a huge amount of power to the traction battery, sometime draining like 3 bar. I didn't felt the need to change the 12v battery since the car was always starting (and I only had problem if it was left in the acc position, so I tried to avoid that).
That's when I began to monitor the traction battery. After some research I believe that the kinetic energy is used mostly to charge the traction battery, which then use an inverter to downsize the voltage to charge the 12v battery. From my understanding, in normal driving the gasoline engine and kinetic energy is used to charge the traction battery, which then trough an inverter charge the 12v battery. My assumption, and depending on my observation, is that if you have a depleted 12v battery, the inverter is constantly used to maintain the 12v battery charge so less energy can go to the traction battery, thus reducing performance. In optimal driving condition the gasoline power the car and the battery, and the battery is used to boost fuel economy. But in "charging mode", the gasoline engine is used for traction and for charging the traction battery, and no traction battery is used to assist the gasoline engine, thus reduced fuel economy. A poor 12v battery seems to force that car in that "charging" state much often than normal. After changing the 12v battery the traction battery got all bar minus 1 and stayed like this for my entire trip. I'll monitor the fuel economy to see how much of a difference it make. I think that even beside the performance not using that much the traction battery and prevent it to drain so low so many time will only help prevent premature wear.
Anyone had similar observation on their car ?
Although the dealer wouldn't confirm the manufacturing date on those Panasonic battery it seems pretty easy to figure. There is a white inscription just on top of the battery in the following format: dd/mm/yy
I've been monitoring the traction battery for the last month and it occurred to me that it was draining pretty fast, being only 2 bar a few time. I already knew that my 12v battery was still the original (more than 7 year old) because I always had problem starting the car if it was left to ACC position for about a min. But I never ever failed to start or even need to jump start it (sometime it took more than a min of trying but I was always successful). So I made the assumption that the traction battery was actually giving some juice to the 12v battery in order to help the car start. I also saw that this process was draining a huge amount of power to the traction battery, sometime draining like 3 bar. I didn't felt the need to change the 12v battery since the car was always starting (and I only had problem if it was left in the acc position, so I tried to avoid that).
That's when I began to monitor the traction battery. After some research I believe that the kinetic energy is used mostly to charge the traction battery, which then use an inverter to downsize the voltage to charge the 12v battery. From my understanding, in normal driving the gasoline engine and kinetic energy is used to charge the traction battery, which then trough an inverter charge the 12v battery. My assumption, and depending on my observation, is that if you have a depleted 12v battery, the inverter is constantly used to maintain the 12v battery charge so less energy can go to the traction battery, thus reducing performance. In optimal driving condition the gasoline power the car and the battery, and the battery is used to boost fuel economy. But in "charging mode", the gasoline engine is used for traction and for charging the traction battery, and no traction battery is used to assist the gasoline engine, thus reduced fuel economy. A poor 12v battery seems to force that car in that "charging" state much often than normal. After changing the 12v battery the traction battery got all bar minus 1 and stayed like this for my entire trip. I'll monitor the fuel economy to see how much of a difference it make. I think that even beside the performance not using that much the traction battery and prevent it to drain so low so many time will only help prevent premature wear.
Anyone had similar observation on their car ?
Last edited by Vansibel; 12-18-14 at 08:35 AM.
#2
Instructor
I have a 2008 LS600hL, and my Traction Battery status (I assume by that you mean the hybrid batteries) seems go fairly quickly from fully charged to fairly depleted. This seems to be the normal operation for the hybrid batteries, I've always assumed. I've only had the car 6 months, though, and have been concerned over the risk of the hybrid batteries failing at some point and leaving me with a big bill to replace them (although pretty much no one has ever had a problem with the LS Hybrid batteries, it seems).
My car has a fairly new starter battery, according to the My Lexus records, so I don't think that would cause my hybrid batteries to fluctuate in and of itself.
What your saying does make a certain amount of sense, though. I'm interested in comments from the other LS600 owners on how much variation you see in your hybrid battery status and whether an older starter battery seems to have an impact on hybrid battery drain.
My car has a fairly new starter battery, according to the My Lexus records, so I don't think that would cause my hybrid batteries to fluctuate in and of itself.
What your saying does make a certain amount of sense, though. I'm interested in comments from the other LS600 owners on how much variation you see in your hybrid battery status and whether an older starter battery seems to have an impact on hybrid battery drain.
#3
I have 08 LS600 with battery since 2009, I can leave the car for 10 days at full minus one bar hybrid battery and come to it where it was. Previous owner had trouble couple of times with the starting battery but it was because he left the car unused for months. I never looked at the impact after I run the car though. I will keep an eye and update.
Hybrid battery does ok strolling in traffic for a mile or so before it fires the engine, unless there are hills or I want to accelerate.
Hybrid battery does ok strolling in traffic for a mile or so before it fires the engine, unless there are hills or I want to accelerate.
#4
One more thing, I realized that the hybrid system decreases the dependency on the electric motor at cold weather, I don't know why but confirmed it multiple times. When it is below 30 degrees, seems that the car does not let me drive much on electric even with full hybrid battery, it fires the engine once I touch the gas paddle. So decrease in fuel efficiency might also be related to the cold weather.
#5
Lead Lap
I had numerous issues on my 600 when my 12v battery was on its way out. TPMS sensors not checking in, couldn't make it through a carwash cycle without the warning to put the car in Park Or Drive, jump starts..nav not working on and on. New trunk battery for $315 and voila... Car is like new again. None of those issues remain anymore. Just like my old 460..a weak battery causes havoc. The 600 is even more sensitive. Its great going through a carwash without hybrid warnings that traction battery needs help lol..best $315 spent to date.
Last edited by CJITTY; 12-19-14 at 04:20 PM.
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GoldGS3
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12-15-09 06:33 PM