12V Battery Light - Not Charging ?
#11
06-28-2018, 12:06 PM
Re: 12V Battery Light - Not Charging ?
Before I did anything to the car, I was getting code P0A7F which is hybrid battery pack deterioration. The red battery light was also intermittently turning on and off, and the hybrid battery wouldn't charge or hold a charge. So I planned on doing some testing.
When I disassembled the battery pack to check the voltages for each battery pack (in pairs) the values were as follows:
13.57
13.38
13.90
13.26
13.28
13.55
13.30
13.13
13.55
13.41
13.33
13.69
Yes I know that just checking the voltages alone won't tell you anything, but I noticed that the ranges are very very different. This has to tell me something right? I still need to find time to do an actual load test, but that is so time consuming.
When I disassembled the battery pack to check the voltages for each battery pack (in pairs) the values were as follows:
13.57
13.38
13.90
13.26
13.28
13.55
13.30
13.13
13.55
13.41
13.33
13.69
Yes I know that just checking the voltages alone won't tell you anything, but I noticed that the ranges are very very different. This has to tell me something right? I still need to find time to do an actual load test, but that is so time consuming.
Measuring voltage can tell you many things, but it almost never tells you everything you need to know; however, your case is an exception. Your pack is completely bad, and 100% of subpacks are bad. Your pack has failed with catastrophic and pervasive self-discharge in 1-2 cells (or more) per subpack.
FWIW, if you EVER measure NiMH cells at 1.2V, they are completely discharged. The fact that yours were UNDER 14.4V nominal means all subpacks have failed.
The initial intermittent 12V light was due to your horrible battery. Below about 1500rpm, the hybrid battery is supplementing the DC-DC to maintain set voltage. IMA motor can't do it alone. If the BCM senses gross imbalance of your 11 voltage values, it can't supplement the 12V charging.
When I assembled everything back, I was getting the other code P1575, but not the P0A7F code. I am using a Bluetooth OBD2 scanner and torque pro on my Android phone and have reset the code. It has came back after some driving. A lot of master mechanic shun these bcz they say it can screw with the ECU. I'm afraid it might have made things worse.......
With the current situation:
With battery disconnected and revving up to 3000 rpm, the volatage went from 9v at idle to 14.13v at 3000 RPM. Btw it's idling at 1000 RPM which is not normal. 9v is ridiculously low and 14v is way too high.
With battery disconnected and revving up to 3000 rpm, the volatage went from 9v at idle to 14.13v at 3000 RPM. Btw it's idling at 1000 RPM which is not normal. 9v is ridiculously low and 14v is way too high.
When battery was connected, the voltage stayed at 12.04V even at 3000 RPM. This is with a brand new battery. The old one was bludging, and I think bcz it was over charging from the 14v.
14V does not over-charge batteries. Most 12V batteries can't attain full charge unless charged at 14.4V for about 4 hours. 12V charging works as follows:
Charge at 0.1C (4A for a 40Ah battery) to 14.4V = 80% charged
Charge while holding 14.4V and continually reducing current for about 4 hours = 100% charged.
Float fully charged battery at about 13.5V to maintain 100% charge.
NOTE: different batteries have different voltages. Some batteries go as high as 15V to attain full charge, and float voltages can vary slightly.
So is there something I was supposed to do after the battery pack assembly? Like some kind of reset procedure?
Please guide me on what the 11 tap voltages are.
Thanks again.
Please guide me on what the 11 tap voltages are.
Thanks again.
Connector here (check subpack voltages without disassembling pack - only need to remove IPU lid):
https://www.greenhybrid.com/forums/f...rminals-31418/
Picture of broken tab here (prevents BCM from getting signal):
https://www.greenhybrid.com/forums/f...tml#post265446
Before you disassembled your pack, everything was working normally given the severe deterioration of the pack. If a P1575 limits current due to the MCM error, then even if the DC-DC can deliver proper voltage, it can't supply proper current.
You need to check your taps on the connector before you do anything else.
#14
07-04-2018, 05:18 AM
Re: 12V Battery Light - Not Charging ?
#15
06-22-2022, 01:34 PM
Re: 12V Battery Light - Not Charging ?
12v not charging second I swapped the battery at AutoZone only light I have on is the red battery light
#16
07-12-2022, 05:34 PM
Re: 12V Battery Light - Not Charging ?
The DC-DC converter sounds like the culprit.
I have two of these, I've replaced both 12V with an oversized 51R and dropped in spare packs. I never needed to do anything with the ECU.
The IMA/CEL lights went out when you disconnected the 12V.
What is the voltage across the battery terminals when idling? It behaves a little differently than a car with an alternator and can show in the 12s when running.
Is the IMA system functioning properly?
I recommend you drive the car until the CEL comes back on. Read the code. I recommend something like this for monitoring voltage while driving:
Amazon.com: LCD Cigarette Lighter Voltage Digital Panel Meter Volt Voltmeter Monitor for Auto Car Truck (1piece): Automotive
and one of these + Torque app to read codes:
http://www.newegg.com/Product/Produc...9SIA1EF0FF3686
Good luck,
Steve
I have two of these, I've replaced both 12V with an oversized 51R and dropped in spare packs. I never needed to do anything with the ECU.
The IMA/CEL lights went out when you disconnected the 12V.
What is the voltage across the battery terminals when idling? It behaves a little differently than a car with an alternator and can show in the 12s when running.
Is the IMA system functioning properly?
I recommend you drive the car until the CEL comes back on. Read the code. I recommend something like this for monitoring voltage while driving:
Amazon.com: LCD Cigarette Lighter Voltage Digital Panel Meter Volt Voltmeter Monitor for Auto Car Truck (1piece): Automotive
and one of these + Torque app to read codes:
http://www.newegg.com/Product/Produc...9SIA1EF0FF3686
Good luck,
Steve
I swapped out my dc dc converter cause my red battery light was on I went thru 3 12v batteries from AutoZone was working fine for a week and a half now I'm back to the same problem 12 v battery draining after charging at home
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