01-17-2020, 03:05 AM | #67 | |
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Say it is allowing for the first start heating pattern, and the 'draw' tailing off as you drive distance. You then interrupt and have a restart. It is probably recalculated to 'reheat' the cabin, and associated losses, which naturally knocks off some mileage range. Do you recover some mileage, if you then continue to drive a decent distance? Keep in mind EV is not just about mileage, it has to include the demands of onboard systems, as part of the calculations. Wh/mile must include both factors. |
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01-17-2020, 05:05 AM | #68 | |
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So for the short. .3 mile journey from start in the morning to the childminder would be better done in petrol mode rather than hybrid or electric? To add: in that very short journey I stop once at a junction the rest is through a 20mph zone. Apologies if I’m sounding thick as mince but no other cars had me scratching my head as much as this one. |
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01-17-2020, 06:43 AM | #69 |
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Started with a full charge this morning, have driven 19 kms and it shows a range of 8 kms left. That's 27 kms total or 16.7 miles. Driving real easy I Hybrid mode. What am I doing wrong???
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01-17-2020, 07:56 AM | #70 | |
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As I see it, if the cabin needs any heat, (besides electric seat heating etc.), you are on a looser, before you even start. BTW, what was the ambient temperature? |
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01-17-2020, 09:16 AM | #72 | |
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I look at in a very simplistic way, trying to get my data together, to see if a 330e touring will cope with my driving profile. You have 10.4kWh usable capacity from the battery pack, fully charged. Your heating system 'electric' heater can draw up to 5.5kWh +/- 10%. Say fully charged, you have a range of 30 miles and you intend to drive at 30mph. Without any 'consumer' demands, you should get that mileage, give or take a couple of miles (depending on the benefit of any regeneration), if you drive until the battery reads ---. Now add the HVAC demands from a cold start. Say it immediately draws 5.2kWh for cabin heat. You drive for 20 minutes and 10 miles (at 30mph). Let's assume the cabin is just coming up to the setting temperature, (probably realistic at 5°C), the electric element is about to back off its demand, but you stop. Instead of the predicted range of 30miles, you have in that short distance of 10 miles, used half the battery capacity. You now have a 10 mile projected range, based on real time data. Giving a total of 20 miles. Hopefully the range will extend, as the energy demand per mile decreases over the next 10 miles, if you were to drive it in one trip. My reasoning based on the following: Drive: 10.4 kWh over 30 miles. 10 miles @ 347 Wh/mile = 3.47 kWh Heating: 5.2 kWh over 30 miles. 20 minutes @ 173 Wh/mile = 1.73 kWh Total energy demand: 5.2 kWh for 10 miles. |
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01-17-2020, 09:29 AM | #74 |
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Definitely do it on the 'mains', if you want to maintain the highest possible EV range.
The charging rate is my dilemma. 10amps from an external wall socket already installed, (my home), won't fully pre-condition in cold weather, will still deplete the battery to some degree. I've got plenty of time to charge the battery, but not the capacity to fully pre-condition, without an extra power supply. The electric heater alone, (not including seats) can draw up to 21amps. |
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01-17-2020, 05:00 PM | #75 | ||
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01-17-2020, 05:09 PM | #76 | |
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01-18-2020, 02:14 AM | #77 | ||
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If I drive my car gently, mixed local and highway and never exceeding 110 kph, it will do 18.4 to 20.1 KWh/100 km If the full 12KWh of battery would be available for driving I would therefore get 65 to 60 km of range. Usually though I can get 39 to 42 km of full electric driving on days where it is 8 to 10 degC. Why? 1) if the cabin heater draws 3000 W (which is hefty) it would consume 3KWh in an hours drive. 2) even when the GOM indicates no range left, the car continues to drive all electric because all EVs apply some kind of 'bottom buffer' as completely depleting the battery is bad for its longevity. 3) likely the battery also has a top buffer (see Bjørn Nyland on YouTube) as also fully charging a battery is not the best. Long story short, I would guess there are only ever 9 to 10 KWh of battery available for electric driving... Probably closer to 9 than to 10. Also not how the GOM really increases the range if you have a longer downhill section and decreases if you do a sharp acceleration in Hybrid mode ( electric assists the ice) |
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01-18-2020, 04:43 AM | #79 | |
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I simply posed one simple scenario. The finer detail of the 'variables', I concluded, was not going to help. BTW, BMW claim 10.4kWh of the battery pack is usable energy. The electric heater unit consumption figure is also from BMW's technical data. |
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01-18-2020, 04:49 AM | #80 |
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01-18-2020, 11:39 AM | #82 |
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So at 60mph mine ranges from 4-5 miles/kw which would imply circa 50mile range... But only when on the flat of course... Given that I can get 32-35 miles in the real world that would seem about right. It never lets you use the whole 12kW battery anyway.
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01-18-2020, 02:36 PM | #83 | |
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Finally, some battery capacity is going to HVAC. [IMG]https://is.gd/BLPDQN[/IMG] https://fullycharged.show/blog/surpr...-depreciation/ |
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01-18-2020, 02:45 PM | #84 | ||
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A heating system cannot draw 5.5 KWh. It could draw 5.5 kW and if you would run it for an hour, it would consume 5.5 kWh. You can only make sensible estimates of physical things if you use correct units |
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01-18-2020, 03:18 PM | #85 |
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01-19-2020, 01:53 PM | #86 | |
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Is there not a regular car battery on board? |
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01-20-2020, 12:52 PM | #87 |
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I've got 11.5Kw of charge into mine before and have seen it down as low as 6% so I reckon there is a little bit more available
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01-20-2020, 01:57 PM | #88 | |
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You have to take Charging Efficiency into consideration. Remember there are energy losses, both from the charger and the battery cells. Together, can account for a higher figure. |
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