TerraRex
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Bimmercode hold state of charge.

Mon Jun 25, 2018 7:52 am

I cannot seem to get bimmercode to enable "Hold state of charge" on my 2015 Rex.
Help greatly appreciated

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TerraRex
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Posts: 6
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Re: Bimmercode hold state of charge.

Mon Jun 25, 2018 8:19 am

i3 user group on Facebook is so darn quick. The reason it's not available is because it is fully charged. The battery has to be <75% to engage the "Hold Charge"

theothertom
Posts: 316
Joined: Mon Mar 20, 2017 6:08 am
Location: South Carolina

Re: Bimmercode hold state of charge.

Mon Jun 25, 2018 9:44 am

Thanks for the follow up

TerraRex
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Re: Bimmercode hold state of charge.

Sat Jun 30, 2018 3:53 pm

I followed a recommendation and assigned this to my Function Key #8.
So quick and easy to simply turn on the REX by hitting this one button (when below 75%).

sipabit
Posts: 75
Joined: Sun Mar 04, 2018 2:01 am

Re: Bimmercode hold state of charge.

Tue Jul 10, 2018 10:19 pm

It also may take a moment. Sometimes it takes a couple minutes for it to actually react. Other times, it's instant. What I don't know though is that if you run out of gas, whether it will switch back to electricity on its own. Would be good to know before needing it on the road.
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.

viking79
Posts: 99
Joined: Wed Apr 16, 2014 3:04 pm

Re: Bimmercode hold state of charge.

Wed Jul 11, 2018 3:05 am

I regularly set hold at 75% and run until I am out of gas and keep driving on electric until I get to a convenient gas station. Totally seamless, and means I am not stopping as often for gas if gas stations are annoyingly spaced. Like "do I stop at this gas station with 30 mi gas range (and 50 mi electric) left because the next one is 35 mi away?" Nope, just use some of the battery.

jadnashuanh
Posts: 4045
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Bimmercode hold state of charge.

Wed Jul 11, 2018 2:04 pm

sipabit wrote:It also may take a moment. Sometimes it takes a couple minutes for it to actually react. Other times, it's instant. What I don't know though is that if you run out of gas, whether it will switch back to electricity on its own. Would be good to know before needing it on the road.

Just for clarification...there are two ways to make a hybrid and they are called either serial or parallel.

A serial hybrid is like a diesel electric locomotive and the i3 REx. They both have engines, but those engines drive a generator...the ONLY thing that drives the actual wheels is the electric motor...the engine drives a generator whose output can either go directly to the electric motors or, if there's excess power available, into the batteries. A special note, though, the engine-driven generator of the REx is only around a 34Hp motor...the i3's electric motor is a 170Hp device. If you think about it, there's no way the REx can provide 170Hp, so under heavy load, you WILL also be using battery power. The way this works, though, is normal cruising doesn't need 170Hp, but, the faster you go, the bigger the hill you want to climb, the more lights you want to run, or the harder you make the HVAC system work, you'll not be able to maintain battery levels. Lots of things go into this, but on flat ground, if you're traveling faster than somewhere around 70mph...your SOC will decrease, even with the REx pumping out as much power as it can. Start to go uphill, it will decrease faster. Slow down, and you might be able to recharge the battery.

A parallel hybrid is one where either the electric motor, or engine, or both drive the wheels of the vehicle. In this type, you could run on only electricity, only gasoline (through the engine), or with both. They type of hybrid will typically have a much smaller battery than a full EV or a serial hybrid.

There's actually a third type that we'll see more of in the next year or so called mild hybrid. These tend to switch many ancillary devices in the vehicle to electrical operation - steering (fairly common now), compressor, water pump, and probably more. To achieve better optimization, they will switch from 12vdc stuff to 48vdc...you can use smaller wires to get the same power when you raise the voltage (think power = volts * amps...raise volts, you can lower amps and use smaller wires, while providing the same power to a device. Smaller wires, less weight, which can help, too. Taking more of the parasitic loads off of the engine means start/stop becomes more efficient as well while maintaining creature comforts fully.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

sipabit
Posts: 75
Joined: Sun Mar 04, 2018 2:01 am

Re: Bimmercode hold state of charge.

Mon Jul 23, 2018 10:51 pm

I'm aware of the differences but thanks for clarifying. It helps. I'm still at a loss though as to 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.
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.

CharonPDX
Posts: 21
Joined: Sat Jul 21, 2018 8:54 pm

Re: Bimmercode hold state of charge.

Tue Jul 24, 2018 1:36 am

So, the car is always "running the wheels" on electricity. No matter what (unless you run so far out of battery+gas that it refuses to move at all.)

When the REx is running, it is supplying electricity to the batteries. The motor then draws power from the batteries to run the wheels. Regardless of if REx is running in "stock US limited" mode or in "Charge Hold" mode, the motive force is coming from the batteries. In both modes, the REx will run the gas tank out of gas (literally for non-US or coded to remove the limit; or "artificial software limit displaying 'out of gas'" in stock US limited mode) and the car will continue to operate on whatever battery charge remains.

If in standard US mode, this means you will probably only have 6% battery remaining (or less, if you had been pushing the car hard so that the REx couldn't keep up.). In Charge Hold mode, you will have whatever threshold you had set it to (default 70%,) again possibly a little lower if you had been pushing the car harder than the REx could keep up with.

I drove my car using Charge Hold mode over 100 miles in a single trip last week. Got on the freeway, enabled Charge Hold, drove ~45 miles, exited the freeway and disabled Charge Hold. Drove around town on battery, got back on the freeway, enabled Charge Hold, drove ~45 miles back, REx ran out of gas just as I was exiting the freeway, but I still had ~50% battery to get the last couple miles from the freeway back home.

alohart
Posts: 1357
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: Bimmercode hold state of charge.

Tue Jul 24, 2018 10:13 am

sipabit wrote:I'm still at a loss though as to whether the car will return from gas back to electricity ones the gas is out.

As explained by others, an i3 is always propelled by electricity, so there's no returning from gas back to electricity. As long as the battery pack isn't fully discharged, propulsion of an i3 would continue even after the REx engine runs out of gasoline and quits.
Aloha,
Art

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

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