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Discussion Starter · #1 ·
Over the last couple of weeks have managed to go pretty low batterywise at least twice. The point here not being that its smart but that both times everything was OK and worked out just fine. Is this just this lousy driver or have you similar experiences????
After an update at the dealership they forgot to charge overnight... Was in a bit of a hurry so took off w 41% SOC. Highway for like 26 km above 100 km to an appointment. At 17% just wanted to go home had a vague idea that a charger was 25 km away. It turned out to be more like 33 km distance...made a pretty cautious albeit anxious ride arrived at the charger with 2%. Topped up for 8 minutes drove another 25ish km.
The second time the fast charger at the destination was busy w an id.4 that seemed to charge forever and then some, way beyond 80%. Found a 11 kW charger so did the stuff we came to do, involved shifting 250 kg of potatoes, long story, came back to 72%. It was pretty chilly around 3C. Drove around 120 km this chilly night w heating and radio etc Cruise Control arrived home w 2%. So predictable, so dependable!!
I look at the state of charge the consumption is not to be trusted in my humble opinion. Will this kill the battery? Hopefully not. Have fun with your MX-30s!
 

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I've done about 450 miles since new and I find the SOC fairly reliable. I have already got used to the power usage according to different driving styles and can estimate consumption for a given journey quite closely. I haven't tried running down to single figure percentages of power and don't fancy pushing the last 2%. I don't think that using the battery to the last couple of percent will do it a lot of good but then is 2% really 2% or is it actually significantly more? I do get the feeling that Mazda has taken a conservative approach to battery management. I have done just one DC charge at the excellent Instavolt. Ambient temperature only 5C but the milkfloat had the cooling fan running. Why?
 

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Discussion Starter · #3 ·
Well one or at least I can only guess. The bad thing with fast charging apparently is to much heat building up potentially damaging cells in the battery. Like in the air chilled Nissan Leaf older models. So maybe to chill the battery?? ? It has to be said that the fast charging of this dude from Hiroshima is not really fast, top effect around 38 kW. But for top ups at lower state of charge it works just fine.
 

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Mazda state that the advertised fast charge rate is achieved at 20C and the charge rate is reduced at low temperature. If that is the case, why does the cooling system operate when the battery is stone cold and the system is throttling the charge rate because of the low temperature? Why is the temperature not allowed to rise to the optimum (or close to it) before the cooling system trips in? Mazda need to do more work to create better outcome. To summarise, the battery was being cooled when it was already cold, and yet, just 16kWhr was charged in 61 minutes. Some way off the advertised 21kWhr in 36 minutes! And, at 70 mph, that precious battery is being asked to provide rather more than it seems to restrict charging to.
 

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Discussion Starter · #5 ·
Well charging with the MX 30 is what it is. The trick is to go to a relatively low state of charge after doing some driving at highish speeds possibly with so called yoyo driving. In practice going beyond 200 miles is not really practical unless you have a really patient, think zen like disposition. Charge to 100%, drive until roughly 10% SOC top up at a 50 kW charger. Destination AC charging is great even If its less cool. I ve done loads and loads of day trips 250 km plus. Going to a 50 kW charger above 50% SOC, at least at lower temp, is a waste of time.
 

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Trust this sound could have been HVAC heating or rather trying to heat battery than cooling.
But fact is fast charging is not really possible here as the max input is setup at 37. Would not be more without any software optimization.

Ps. SoC at 0% leaves ~3kwh which is like 8-9% of the capacity. You can still make 15km from SoC at 0%

Wysłane z mojego SM-G973F przy użyciu Tapatalka
 

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Discussion Starter · #7 ·
Just out of curiosity how do you know that the low battery buffer is 3 kWh? And how much of it is available?? Did you test it? 15 km sounds great😃
 
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