louisgrenier
Posts: 30
Joined: Sat Oct 25, 2014 4:24 am

Re: Bimmercode hold state of charge.

Thu Aug 02, 2018 5:26 am

sipabit wrote:whether the car will return from gas back to electricity ones the gas is out. This scenario would be the opposite of what the car is "supposed" to do. Normally, it runs out of electricity and goes to gas. I'm wondering if the reverse would happen if there's still loads of electricity left.
There is no such thing as "back to the electricity", or "back to the battery". Like explained by others, it always takes the power (energy) from the battery. REX running or not. So you don't have to fear to be stuck without power in the scenario you describe. As long you have energy in the battery. The REX will only help to maintained the battery level. So don't fear the i3 to stop when the REX will stop. There is no such thing as switching the power source from the REX to the battery. Or vice versa. Power comes from the battery , REX running or not.

Louis

Mehdi
Posts: 8
Joined: Mon Dec 03, 2018 7:39 am

Re: Bimmercode hold state of charge.

Mon Dec 03, 2018 7:51 am

Is it possible to actually "raise" the state of charge? For example, if I am at 50% battery charge, could I somehow make the extender to keep charging the battery, say up to 75%?

alohart
Posts: 1676
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: Bimmercode hold state of charge.

Mon Dec 03, 2018 1:00 pm

Mehdi wrote:Is it possible to actually "raise" the state of charge? For example, if I am at 50% battery charge, could I somehow make the extender to keep charging the battery, say up to 75%?
I have not read of anyone discovering what needs to be done to make this possible.
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

jadnashuanh
Posts: 4488
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Bimmercode hold state of charge.

Mon Dec 03, 2018 6:04 pm

Mehdi wrote:Is it possible to actually "raise" the state of charge? For example, if I am at 50% battery charge, could I somehow make the extender to keep charging the battery, say up to 75%?
Considering the HP output of the REx, which is often not able to keep up with holding the charge if you're climbing a hill or traveling fast, I doubt it would work, or if it did, it wouldn't very often. Vehicles that CAN do it all have a much a larger engine and gas tank. It has about the power of one of the first VW bugs...IOW, not a lot.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

Mehdi
Posts: 8
Joined: Mon Dec 03, 2018 7:39 am

Re: Bimmercode hold state of charge.

Wed Dec 05, 2018 8:43 am

I find that, except for cold nights in the winter or a long uphill drive, the REX is more than capable of charging the battery to a higher level than it is but it is set to not do that. I did however read someone saying that it is possible to put the car in emission test mode and that would cause the battery to be charged to a higher level. This means the car has to be parked, the lift gate has to be open and this can be done only for 20 minutes at a time. But at least it is an option.
Last edited by Mehdi on Wed Dec 05, 2018 3:16 pm, edited 1 time in total.

jadnashuanh
Posts: 4488
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Bimmercode hold state of charge.

Wed Dec 05, 2018 3:09 pm

It all depends on your driving style, primarily speed, but lights, heating, and grades take more power and stop and go with rapid acceleration is a factor. The motor can draw up to 126Kw (that's approximately the conversion of 170Hp), which is like nearly 4x what the REx can put out not counting the other things drawing power in the car. Certainly, you're not doing that constantly, but in stop and go, the regen is not perfect, and the REx would have a problem at times. Freeway driving with traffic at 70-80mph with the lights, heat, (or a/c) will put it right on the edge or over capacity.

If BMW wanted the car to be a no-nonsense replacement for an ICE, in this hybrid, they would have supplied a larger engine and gas tank. that they didn't should mean something to people if they think about it. It was made as a city car. Drive it to work or shopping, charge if needed, then drive it home and charge it up. The REx was an emergency backup in case you miscalculated. that you can use it for longer trips is sort of a secondary, somewhat limited benefit, but it has compromises.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

sipabit
Posts: 106
Joined: Sun Mar 04, 2018 2:01 am

Re: Bimmercode hold state of charge.

Fri May 24, 2019 11:01 am

louisgrenier wrote:
Thu Aug 02, 2018 5:26 am
sipabit wrote:whether the car will return from gas back to electricity ones the gas is out. This scenario would be the opposite of what the car is "supposed" to do. Normally, it runs out of electricity and goes to gas. I'm wondering if the reverse would happen if there's still loads of electricity left.
There is no such thing as "back to the electricity", or "back to the battery". Like explained by others, it always takes the power (energy) from the battery. REX running or not. So you don't have to fear to be stuck without power in the scenario you describe. As long you have energy in the battery. The REX will only help to maintained the battery level. So don't fear the i3 to stop when the REX will stop. There is no such thing as switching the power source from the REX to the battery. Or vice versa. Power comes from the battery , REX running or not.

Louis
I see what you're saying. There's no gas engine. The gas feeds the generator which converts to electricity which the car runs on. Essentially, it's always running on electricity. I get that. However, if you manually switch the mode to run the REX while you still have battery beyond what the REX is outputting (meaning state of charge is say at 40%), I'm not sure the software will recognize that the car still has juice and will continue running the car since the REX is designed as a backup once SOC is less than 6%.

So you're saying that if I switch the REX on with 30% battery left (or anything over 6%), run out of gas, then the car will definitely continue running? That would be great, but I was just too scared to test it. Have you done it? Or just a theory that it will?
A fanatic of all things electric. Ridables like electric ice chests and stand up scooters I adore. Drones like DJI, I root for. I'm a fan of both, but nothing beats my love for my 2016 i3 Rex with Deka World. Shhh, don't tell my wife.

jadnashuanh
Posts: 4488
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Bimmercode hold state of charge.

Fri May 24, 2019 6:52 pm

The car will continue to run until it runs out of battery power. It doesn't matter if you got that power from plugging it in, or from the REx trying to maintain. Note, the maximum level the REx will charge to is whatever it was when it first was turned on...IOW, if, say you had not tweaked the thing by coding to raise the level (depending on where you live and the model year), if it automatically came on at 6%, that's the max it would try to maintain. If it is coded to the max, and you turned it on at <75%, that would become the new goal. Depending on the load on the car, the REx can turn on/off, and vary it's RPM to produce more or less power, but you're always running on electricity...the car doesn't care where it comes from. Run out of gas, as long as there's battery capacity left, it will just continue.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

alohart
Posts: 1676
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: Bimmercode hold state of charge.

Sat May 25, 2019 11:41 am

jadnashuanh wrote:
Fri May 24, 2019 6:52 pm
The car will continue to run until it runs out of battery power.
There have been a few reports of REx propulsion stopping when the engine ran out of gasoline despite having battery charge remaining. Apparently, turning the car off and then on again allowed driving to continue. This behavior is almost certainly due to a software bug that likely exists in only a few system software versions.
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

louisgrenier
Posts: 30
Joined: Sat Oct 25, 2014 4:24 am

Re: Bimmercode hold state of charge.

Mon May 27, 2019 6:49 pm

""""So you're saying that if I switch the REX on with 30% battery left (or anything over 6%), run out of gas, then the car will definitely continue running?

Yes. This is the way i drive it when i know that i have long stretch to do. I hold the the holding point to 75%, and use all the fuel i have. If i was speeding over 90 km/h, or if i am going up a mountain, the battery will slowly go down even if the REX is running. When the fuel is depleted, the REX stops. The car continue without knowing it. The battery will go down faster of course now that the REX is no more there to put some juice in the battery.

Again, there is no connection, software or else, between the REX and the electric engine running the car. The car moves as long there is power left in the battery.

Louis

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