Battery level - stupid question


Bionicman

E powertrain proponent
Likes
385
Location
WA
I ran my battery close to dead today...
The display showed NO charge left yet was still going?
My question is does the display tell you something else when out of electrons or does the bike just stop working?
So far the bike just plain works. With all the hidden tech in the Alta I pray it just keeps working like my other Ebikes for years to come.
 
  • Like
Reactions: Rix

Mark911

Well-known member
Likes
1,123
Location
Corona Ca
I'm pretty sure Alta incorporated safeguards to prevent damage from anyone running the pack totally empty. The BMS will shut off the pack at a voltage specified by Alta to prevent damage to the cells. The only "extra" battery in the bike is the little 9v battery housed inside the main ECU under the seat. I'm not sure if the display has it's own backup battery much like a cell phone. If there's any programable data inside the display it probably does have a battery. Remember, even when the main pack says "dead" it really still has quite a bit of voltage left, probably somewhere between 2.4 and 2.8 volts per cell. That's still roughly 200v! More than enough to power the display and still not threaten the sensitive to under voltage 18650 cells.
 
  • Like
Reactions: Rix

datadog

Well-known member
Likes
286
Location
USA
There is some estimation/prediction going on with the SOC. Did you key cycle? Sometimes this provides more accuracy.
 

datadog

Well-known member
Likes
286
Location
USA
I'm pretty sure Alta incorporated safeguards to prevent damage from anyone running the pack totally empty. The BMS will shut off the pack at a voltage specified by Alta to prevent damage to the cells. The only "extra" battery in the bike is the little 9v battery housed inside the main ECU under the seat. I'm not sure if the display has it's own backup battery much like a cell phone. If there's any programable data inside the display it probably does have a battery. Remember, even when the main pack says "dead" it really still has quite a bit of voltage left, probably somewhere between 2.4 and 2.8 volts per cell. That's still roughly 200v! More than enough to power the display and still not threaten the sensitive to under voltage 18650 cells.

The 'extra' 9v provides voltage to start the BCU. Without it, no drive.
 

datadog

Well-known member
Likes
286
Location
USA
It's a very special lithium, don't replace it with something else or you will probably find yourself stranded. You can find it at Lowe's.
 

privateer703

AOF Addict
Likes
687
Location
Altoona, PA
I can find it at Lowes!!!!!
I imagine that Alta designed the charge system to allow you to get home when charge is extremely low. Similar to how your gas gauge goes below zero.
I'm curious of the power you have at that SOC. If you try full throttle at that charge what happened?
 

Bionicman

E powertrain proponent
Likes
385
Location
WA
I made it back to the truck no problem. Just curious how much more range the bike actually had in it. If there is a severe reduced power setting for “get you home” power or if deisplay starts blinking saying “hey idiot your going to be pushing in T minus 3.2.... or if bike just goes to sleep & says FU idiot push me out of the woods!?
 

Bionicman

E powertrain proponent
Likes
385
Location
WA
When you run the battery completely dead, you can still about 1/4 mile at about 2-3 mph. Eventually, the bike will refuse to move.
You can still charge it up after that; as mentioned before, the pack protects itself from over/under charging.
Thank you!
 

OneLapper

"You don't *really* need the water pump...."
Forum's Sponsor
Likes
989
Location
Connecticut
When you run the battery completely dead, you can still about 1/4 mile at about 2-3 mph. Eventually, the bike will refuse to move.
You can still charge it up after that; as mentioned before, the pack protects itself from over/under charging.

Been there, done that!
 

Trialsman

Well-known member
Likes
593
Location
Pittsburgh
Here is another battery question that I figure is stupid and that every Alta owner knows....except me. Can the A pack battery be used in place of an R pack? I have my '19 EXR but I could just keep my other Alta '17 MX with the A type battery if I could use it in the EXR (granted not as much power or range.)
 

Rashid510

Well-known member
Forum's Sponsor
Likes
1,128
Location
South San Francisco, CA
Here is another battery question that I figure is stupid and that every Alta owner knows....except me. Can the A pack battery be used in place of an R pack? I have my '19 EXR but I could just keep my other Alta '17 MX with the A type battery if I could use it in the EXR (granted not as much power or range.)

Unfortunately no. The R pack has a different signal and HV connector than the A pack. Pigtails dont really work either....
 

Similar threads

Top Bottom