Does 2% really mean 2% or is there a "reserve" in the battery?

[Marshall G]

As my battery dwindles towards the end of the ride and I start looking for the truck, range anxiety starts to set in. For the record, I've done several 35+ mile pretty hard-core single-track desert rides with hills, sand washes, whoops, rocks, cactus - pretty much all kinds of varied terrain. Loving the bike (hate the phone/Arkenstone thing - it can't even keep track of simple mileage).

However, on a couple of occasions, I get back to the truck with 2% battery remaining. I'll ride around in circles trying to kill the battery, but I don't want it to die while I'm 1/2 mile from the truck, so I'm hesitant to run it until dead. So, has anyone run until dead? Is it linear? Does 2% really mean, I've got like 1 mile to go? Or, does it have more in the "tank" so you can get back to the truck? Like a reserve.

Any input is appreciated. Next time, when I get home from a ride like this, I'll put my wife in the truck and have her follow me around until I run out, but in the meantime...

Thanks,
mg

 

[markanddona]

As my battery dwindles towards the end of the ride and I start looking for the truck, range anxiety starts to set in. For the record, I've done several 35+ mile pretty hard-core single-track desert rides with hills, sand washes, whoops, rocks, cactus - pretty much all kinds of varied terrain. Loving the bike (hate the phone/Arkenstone thing - it can't even keep track of simple mileage).

However, on a couple of occasions, I get back to the truck with 2% battery remaining. I'll ride around in circles trying to kill the battery, but I don't want it to die while I'm 1/2 mile from the truck, so I'm hesitant to run it until dead. So, has anyone run until dead? Is it linear? Does 2% really mean, I've got like 1 mile to go? Or, does it have more in the "tank" so you can get back to the truck? Like a reserve.

Any input is appreciated. Next time, when I get home from a ride like this, I'll put my wife in the truck and have her follow me around until I run out, but in the meantime...

Thanks,
mg

Don't ride by yourself in the summer in the desert and always carry a tow strap. What HP and re-gen are you running?

 

[FreddyFugazi]

I dont think that is a good idea. The owners manual says not to let the battery drain completely under the storage section and I have read a few cases where people who did let it drain completely had to have their battery replaced. I am not sure if that issue has been resolved but I would go by the manually and not risk it.

 

[Marshall G]

I dont think that is a good idea. The owners manual says not to let the battery drain completely under the storage section and I have read a few cases where people who did let it drain completely had to have their battery replaced. I am not sure if that issue has been resolved but I would go by the manually and not risk it.

Yikes. Well I didn't run it that low on purpose. The ride just dictated it. I'd like to finish with 25% remaining, but I guess battery technology isn't there yet.

 

[Marshall G]

Don't ride by yourself in the summer in the desert and always carry a tow strap. What HP and re-gen are you running?

I never said I was riding by myself. And I do carry a tow strap (always have - and I've been on both ends of it, on other bikes). I'm running 29 hp and 25% regen on mode 1. 32 hp and 35% regen on mode 2 and I toggle between them.

 

[FreddyFugazi]

Next time, when I get home from a ride like this, I'll put my wife in the truck and have her follow me around until I run out, but in the meantime...

This is what I think would be a bad idea just given what I've read. The battery really shouldn't get bricked if it fully drains. I'm no expert but I'm pretty sure that is a Stark issue not a battery tech issue.

I'm with you on trying to save 20-25% of the battery when planning a ride to avoid any problems but circumstances can still put you in a sticky situation sometimes as you have found. I'm surprised the bike didn't go into a limp mode at 2%. When I had a Surron it would go into a limp mode around 15% SoC to extend the battery life. I intent to use a low power map (10-15hp) when below 30% SoC if I am worried about getting to my destination.

 

[Marshall G]

Sorry, what's SoC?

 

[Marshall G]

Guessing state of charge.

 

[markanddona]

I never said I was riding by myself. And I do carry a tow strap (always have - and I've been on both ends of it, on other bikes). I'm running 29 hp and 25% regen on mode 1. 32 hp and 35% regen on mode 2 and I toggle between them.

I had mine on 35 and it lit the tire up on pavement! Stay safe bro. Did you get the Ti kit?

 

[markanddona]

I had mine on 35 and it lit the tire up on pavement! Stay safe bro. Did you get the Ti kit?

 

[markanddona]

This is what I think would be a bad idea just given what I've read. The battery really shouldn't get bricked if it fully drains. I'm no expert but I'm pretty sure that is a Stark issue not a battery tech issue.

I'm with you on trying to save 20-25% of the battery when planning a ride to avoid any problems but circumstances can still put you in a sticky situation sometimes as you have found. I'm surprised the bike didn't go into a limp mode at 2%. When I had a Surron it would go into a limp mode around 15% SoC to extend the battery life. I intent to use a low power map (10-15hp) when below 30% SoC if I am worried about getting to my destination.

Doesn't stark have several videos of Taddy and the boys running them down to zero?

 

[Slothie]

down to zero is fine. it is already within cell specs. you cant discharge it too deep while riding.
until you ride it to zero and put it then 3 months empty in your garage all is fine.

 

[Marshall G]

down to zero is fine. it is already within cell specs. you cant discharge it too deep while riding.
until you ride it to zero and put it then 3 months empty in your garage all is fine.

Ok, that's good. But what about the original question. Is the discharge linear, or when you get towards 'empty' will it go further as a reserve to get you back to the truck? Thanks.

 

[Slothie]

discharge is mostly never linear. soc (state of charge) is "interpretation" of the manufacturer. Nobody knows were they set 0 or 100%
datasheet from cells it should be 3.0v/4.2v but to have kinda double lifespan they charge only to 4.10/4.12v.
The Problem with a SOC is that you have different conditions. you will have 10-15% more Range between Winter and Summer.
So in Summer your 2% left can be 2 miles and in Winter at 2% left you may only get 0,2miles.
that means for our vargs: just test it. Ride around your house the last 5-4-3-2-1-0% to see how your bike reacts. Dont be gentle, always push max power as possible because the bms "may" cut earlier under load. If you ride at 5mph steady you will get the max "rest-range" out of it. If you squeeze it quick you get the best result because if shit happens and you know you have 5 miles left to ride, just ride as slow as you can to reach your truck/home.