^^^^^ Now that is excellent!
Very informative, Thank you drd....
Very informative, Thank you drd....
A flooded lead-acid battery should be around 12.65V or 12.7V (when fully charged); at 12.0V, the battery would be pretty darn empty. A lead-acid battery will start sulfating pretty rapidly once it drops to 12.4V or lower, especially if it is warm out - and will die rather rapidly (less than 3 years) even though it isn't seeing much use. Maybe the Bolt doesn't use a L-A battery?Wow - that is quite a core dump (showing my age) - anyhow given that
When the vehicle cord is not plugged in
I do not see the need for a trickle charger.
- The Hybrid/EV Powertrain control module (HPCM2) will check the 12V battery every 4 days (2.5 to 3 days) and if the voltage is below a threshold of 12.0 may activate battery maintenance. If the high voltage battery state of charge is greater than 40% and the propulsion system is not active, Hybrid/EV Powertrain control module (HPCM2) will send the voltage set point to the engine control module (ECM). The engine control module (ECM) will send this to the 14V Power Module. Battery maintenance mode will charge the battery for 45-90 minutes..
A 12V battery will not start sulfating at 12.4 volts. At 12.4 volts, the battery is considered to be ~80% charged. You need to run the battery down past 40% or 11.9 volts before sulfation really becomes an issue.A flooded lead-acid battery should be around 12.65V or 12.7V (when fully charged); at 12.0V, the battery would be pretty darn empty. A lead-acid battery will start sulfating pretty rapidly once it drops to 12.4V or lower, especially if it is warm out - and will die rather rapidly (less than 3 years) even though it isn't seeing much use. Maybe the Bolt doesn't use a L-A battery?
The rest of the charging logic sounds a heckofa lot better than the LEAF used for its 12V L-A battery.
Yes it will. It will START sulfating at 12.4V. Sulfation is caused by a chronically undercharged battery (not 'severely' undercharged, undercharged often). Sulfation happens when a battery is not fully recharged fairly often, and yes it happens starting at 12.4V.A 12V battery will not start sulfating at 12.4 volts. At 12.4 volts, the battery is considered to be ~80% charged. You need to run the battery down past 40% or 11.9 volts before sulfation really becomes an issue.
Sorry for joining the convo late but I tested this the other day. Battery is at about 12.8 ish when idle and Bolt is unplugged or off. With the Bolt "on" it reads 14.2 when you multimeter it. When the Bolt is plugged up to a HVB charger it also reads between 14.1 and 14.4. So the Bolt does charge the 12 volt battery when the HAVE is plugged into a Lvl 1 or 2 charger and when the engine is "on". Have not tried to test with DC fast charge active but I cannot see the outcome being any different. Hope this helps.
After you post, you get the chance/choice to "Edit" your post. This saves the dilemma of a second post, and makes the original clearer to all readers. (Sometimes a second post gets "lost" behind a rapid responder's comment.) My typing skills are poor and I get lots of chances to "edit"! Welcome aboard!HAVE = HVB ... Auto correct fail...
Charging System Description and Operation
12 V Battery The following information is for the 12 V battery only.
For information about charging the high voltage drive motor batteries, refer to Drive Motor Battery System Description.
Charging System Operation The purpose of the charging system is to maintain the battery charge and vehicle loads. The main difference between a conventional generator charging system and this system is that the generator has been replaced by the 14V Power Module. The 14V Power Module provides the power to charge the battery from the high voltage system. There are 7 modes of operation and they include:
- Battery Sulfation Mode
- Normal Mode
- Fuel Economy Mode
- Headlamp Mode
- Voltage Reduction Mode
- Battery Maintenance Mode
- Plant Assembly Mode
I know this is a very old post, but we recently purchased a 2020 Bolt to replace a 2013 C-Max plugin hybrid.
Thank you for posting this for us all to learn more about the car.
This information is very good to know, and very different from the Ford. The Ford would text me that the 12v battery was low, and to plug in the car to charge. The problem was that it did nothing to charge the 12v battery! I could leave it for days and it would not charge the 12v battery! This was a big problem, as we towed that car behind a motorhome, and leaving it in Neutral would drain the 12v battery more than just having it parked.
Glad GM has done a better job.