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Posted

There is a YouTube video posted on one of these forums by Engineering Explained that explains the chemistry of LFP and how to get the longest life out of your batteries.

 

He explains what Tesla say for their LFP batteries and he goes through why they recommend that. He also goes through what Ford say.

 

Typically, manufacturers suggest you charge to 100% and run down the battery to less than 20% and then recharge.

 

The reason for doing this is to recalibrate the state of charge/range calculator. I explained earlier why it’s very difficult (read impossible) to determine the state of charge between 50% and something like 85%.

 

If you are prepared to sacrifice the accuracy of the range display, then you will get the most longevity out of your battery by keeping it  in the lowest state of charge possible but above 0%. 
 

If you do this, your range remaining indication is not accurate and it gets worse as time goes by, it’s only reset by charging to 100% and the batteries actual capacity cannot be determined until you go below 10%.

 

The chemistry is clear and cannot be disputed.

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Posted

This is the video, there are 4 or 5 recommendations, there is no shortcut but to watch the video.

 

He explains the chemistry and he explains why he gives the recommendation.

 

this is specific for LFP chemistry and does not apply to NMC.

 

 

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Posted

Edit:  durn....I was still typing out my long winded post talking the same video JB posted above....passing in the night....didn't see he has posted the video just minutes below until after I posted my post.

 

A pretty good 18 minute video on EV LFP  NMC/NCA battery charging from several standpoints of EV usage and battery life.  And it even talks that recent study talking how always keeping your LFP charged to a high level might be detrimental to its life span...and this guy points out that recent study acknowledges another recent study indicates keeping the EV LFP highly cared (except for extended storage/non use of months) does "not" affect the LFP battery lifespan.    

 

And for those listening-in don't confuse Lithium NMC/NCA EV batteries with Lithium LFP batteries....two different battery chemistries with two different best care & charging practices.

 

For Lithium NMC/NCA type batteries  EV manufacturers recommend only charging to 80% except when you need to take a long trip and want to start off with max range at 100% charge. 

 

Whereas Lithium LFP type batteries EV manufacturers recommend a weekly-to-monthly charge to 100% to recalibrate the charge percentage indicator and every 3 to 6 months letting the battery drop to 10% and recharging to 100% which accomplishes a full recalibration of the charge percentage indicator.

 

 

 

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Posted

To be clear.

 

Regarding BYD LFP cars…

 

Charging to 100% calibrates the 100% SoC level.

 

Discharging below 10% tells the car what the capacity of the battery is (ie what SoH is).

 

The cars BMS uses 2 techniques to determine both SoC and SoH.  The first is Coulomb counting (this gets less and less accurate until it’s recalibrated by discharging below 10% followed by recharging) and secondly achieving peak voltage which tells the BMS the SoC is 100%.

 

Charging to 100% does not tell the BMS the capacity of the battery.  Measuring coulombs from 100% SoC to less than 10% or recharging from below 10% to 100% allows the BMS to measure the Coulombs and determine SoH.

Posted
15 minutes ago, JBChiangRai said:

 

If you are prepared to sacrifice the accuracy of the range display, then you will get the most longevity out of your battery by keeping it  in the lowest state of charge possible but above 0%. 

Question: I haven't see in any of these reports/studies giving specifics examples of "how much more longevity" really is.   Is it another 100,000km...is it another 2 years?  And the studies/reports also talk the EV battery is going to probably last a long time even if DC Fast Charging all the time.   It's like it's probably detrimental but we really can give specific numbers as to how many less Km's/less years of life that means. 

 

Unless a person plans on keeping the EV well past the battery's warranty period like for example BYD's battery warranty period of  8 years/160,000Km (whichever comes first).   And where I saw "....well past..." I mean a person is shooting for say 15 years/300,000Km then i really can't see babying the battery, doing more frequent charging because a person keeps the EV well below 100% charge, etc.  

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Posted
13 minutes ago, Pib said: 

 

Whereas Lithium LFP type batteries EV manufacturers recommend a weekly-to-monthly charge to 100% to recalibrate the charge percentage indicator and every 3 to 6 months letting the battery drop to 10% and recharging to 100% which accomplishes a full recalibration of the charge percentage indicator.

 

 

 


I will watch the video, but a quick question.

 

I see some people stating that the 10% to 100% charge should be done at a slow charging speed, i.e. AC, to effectively achieve battery balancing, is that true ?

Posted
6 minutes ago, Pib said:

Question: I haven't see in any of these reports/studies giving specifics examples of "how much more longevity" really is.   Is it another 100,000km...is it another 2 years?  And the studies/reports also talk the EV battery is going to probably last a long time even if DC Fast Charging all the time.   It's like it's probably detrimental but we really can give specific numbers as to how many less Km's/less years of life that means. 

 

Unless a person plans on keeping the EV well past the battery's warranty period like for example BYD's battery warranty period of  8 years/160,000Km (whichever comes first).   And where I saw "....well past..." I mean a person is shooting for say 15 years/300,000Km then i really can't see babying the battery, doing more frequent charging because a person keeps the EV well below 100% charge, etc.  

 

I don’t know by what percentage this makes a difference.

 

He also covers in passing that temperature has a significant effect. I would be interested to know by how much temperature makes a difference.

 

My garage is air-conditioned, but I only tend to turn it on when charging, and we have a significant surplus in solar power.

 

We have 18 kW of grid-tied inverters and it’s very difficult to output more than maybe 8 or 9 kW, charging the car when it’s sunny, allows me to get the full output power of the inverters, but not always, we still derate to 12 kW sometimes.

Posted
13 minutes ago, Andrew Dwyer said:


I will watch the video, but a quick question.

 

I see some people stating that the 10% to 100% charge should be done at a slow charging speed, i.e. AC, to effectively achieve battery balancing, is that true ?

 

I don't know....I've seen that in other forums like on reddit from everyday folks like myself...but I've never seen any of those posts provide some reference from the EV manufacturers.....like a quote from the EV manual, some EV technical/specifications document.    

 

Personally, I think it probably would provide a "little bit better balancing" due to less battery heating & stress and giving the BMS more time of around 9 to 10 hours to fully recharge with a 7KWH wall charger compared to around 1 hour with a DC Fast Charger.  And don't ask what a "little bit better balancing" means in specifics as I don't know.....just like battery studies/reports that don't give specifics on just how many more or less years/kilometers a battery might last if Fast or Slow charged.

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Posted
11 minutes ago, Andrew Dwyer said:


I will watch the video, but a quick question.

 

I see some people stating that the 10% to 100% charge should be done at a slow charging speed, i.e. AC, to effectively achieve battery balancing, is that true ?


Sorry, you didn’t address this to me, but I will jump in if that’s OK.

 

I am fairly sure BYD use active balancing, the BMS is balancing the cells all the time so speed of charging probably won’t affect that process, other than it may not have finished balancing the cells for some considerable time after finishing charging.

 

For those cars that have passive , balancing, typically MG, then the balancing occurs at the end of the AC charge cycle. The system uses a system of resistors and wastes a little energy as it brings all the batteries to 100%. Individual cells either take more charge or blow off the excess power through resistors generating heat.
 

When I built the LFP battery pack for my solar power, I added active balancers. I did that specifically because I didn’t want to ever charge them past 80% unless notified of a power cut if I had allowed passive balancing then they would never have balanced because I never charged them to 100%.

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Posted

Here's what the BYD Atto manual recommends for SOC recalibration and also if not using the EV for over one week.

 

image.png.591598d4007d3e25c714bfb754d04133.png

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Posted
2 minutes ago, Pib said:

Here's what the BYD Atto manual recommends for SOC recalibration and also if not using the EV for over one week.

 

image.png.591598d4007d3e25c714bfb754d04133.png


Again, watch the video if you want to know why they recommend this.

 

This will not give you the maximum battery life.

Posted

What you do is a compromise.

 

Maximum battery longevity is achieved through inaccurate range display.

 

Accurate range display will not achieve maximum battery longevity.

 

So you have to decide which you want. You can have one or the other, but you cannot have both.

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Posted
10 minutes ago, JBChiangRai said:


Again, watch the video if you want to know why they recommend this.

 

This will not give you the maximum battery life.

I did watch it....I understand what this study says can be the detrimental effects....effects with no "specific metrics" as to how much degradation may be caused such as reducing battery life span from say 15 years to 12 years....reducing battery Km life span from 400,000 to 350,000, etc. 

 

 And at the the 17 minute point of the 18 minute video the guys says the study he primarily talked admits another study has different results that there is more battery capcity fade if consistently keeping the LFP battery charged to lower levels as compared to higher levels.  Which study do you believe.   And regardless of which study is correct it sure would be nice if the studies gave some "specific metrics" as to what the typical EV driver should expect in terms of less or more battery life after X-amount of years/kilometers.

 

image.png.d6cfc0ee14cc6715d3f9266ded87abc6.png

 

 

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Posted
1 minute ago, Pib said:

I did watch it....I understand what this study says can be the detrimental effects....effects with no "specific metrics" as to how much degradation may be caused such as reducing battery life span from say 15 years to 12 years....reducing battery Km life span from 400,000 to 350,000, etc. 

 

 And at the the 17 minute point of the 18 minute video the guys says the study he primarily talked admits another study has different results that there is more battery capcity fade if consistently keeping the LFP battery charged to lower levels as compared to higher levels.  Which study do you believe.   And regardless of which study is correct it sure would be nice if the studies gave some "specific metrics" as to what the typical EV driver should expect in terms of less or more battery life after X-amount of years/kilometers.

 

image.png.d6cfc0ee14cc6715d3f9266ded87abc6.png

 

 


I agree with you, it didn’t go far enough by explaining how large the effect was.

 

I tend to believe what the Tesla Guru says and that higher state of charge is detrimental. It’s what I’ve also read on battery university.  EE does explain the chemistry behind this and it make sense.

 

Generally, I find EE quite good, he spent almost 18 minutes explaining why a high charge state degrades the battery and only a few seconds saying there’s one study that contradicts this.

 

It’s easy for me to keep my SoC low because most of my journeys are 10 to 30 km, I only go to Chiang Mai occasionally and only once further than that in the last five years.

 

Until I watch that video, I used to keep SoC between 80 and 100%, I don’t do that anymore.

Posted
On 10/18/2024 at 3:40 PM, JBChiangRai said:


11 months of the year I have more solar power than I can use.  Most years it’s every month.

 

I do commute occasionally to our house in Chiang Mai.  That house has a charging point for my daughters MG4, but it doesn’t have solar power, so it costs me. I would like to be able to charge up at Chiang Mai using my 30,000 baht Rêver credit, but it’s almost impossible because everybody is free charging.

 

I would like to go on a road trip to Khao Lak, but again that’s impossible, unless I pay for all my charging.

Your comment slipped by me on first read but actually, there are plenty of Rever chargers for you to use in CM during on peak hours. There is only one CS that has free charging 24/7 in CM. All the others are available at Thb8/kWh and they are almost always available.

Posted
On 10/18/2024 at 2:47 PM, josephbloggs said:

Just curious: are you guys really going out of your way to go to free BYD charging points even though they seem to be busy often? Is it really worth a journey when it only costs you 200 baht or so in electricity to charge it at home (for those without solar)?

Personally I don't think I would bother.  (200 baht figure is not accurate but my brain remembers it being around that). 
 

I was thinking about your comment as to whether it’s worth it. I have attached my consumption record for my two meters, one for the house and one for the wall charger. Bear in mind that both are TOU meters and that I also have solar, albeit a small setup, that reduces my consumption during sunlight hours.

 

So, is it really worth it? In my case, probably not but I’ve never been one to look a gift horse in the mouth.

IMG_20241019_183701.jpeg.d6989b989e4150b70dd378fa24889561.jpegScreenshot_2024-10-19-18-32-49-27_bac80a73f0b0b29d8e16cfa487e8fed1.thumb.jpeg.181b84cb6f56b8f5d5c509198f9b7139.jpeg

 

 

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Posted
42 minutes ago, Gweiloman said:

Your comment slipped by me on first read but actually, there are plenty of Rever chargers for you to use in CM during on peak hours. There is only one CS that has free charging 24/7 in CM. All the others are available at Thb8/kWh and they are almost always available.


We have a house in Bo Sang with a wall charger, I can charge there at normal PEA rates, which is better than the paid Rêver chargers.

 

I would like to charge for free but it’s a fair drive to the free ones and eats into my time with my daughters.

 

After January promotion ends it should be ok.

Posted
12 minutes ago, JBChiangRai said:


We have a house in Bo Sang with a wall charger, I can charge there at normal PEA rates, which is better than the paid Rêver chargers.

 

I would like to charge for free but it’s a fair drive to the free ones and eats into my time with my daughters.

 

After January promotion ends it should be ok.

What I meant is that since you have 30,000 worth of credit, you don’t need to bother with free charging. You can just charge when free charging isn’t available. 
 

Is there any way your credits can be transferred? I’m willing to buy some off you if you have no intention or are unable to avail yourself of it. I’ll start with a lowball offer of Thb1. @Pib and @Andrew Dwyer will probably jump in with better offers. Maybe even @KhunLA.

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Posted
2 minutes ago, Gweiloman said:

What I meant is that since you have 30,000 worth of credit, you don’t need to bother with free charging. You can just charge when free charging isn’t available. 
 

Is there any way your credits can be transferred? I’m willing to buy some off you if you have no intention or are unable to avail yourself of it. I’ll start with a lowball offer of Thb1. @Pib and @Andrew Dwyer will probably jump in with better offers. Maybe even @KhunLA.


LOL, my 30,000 THB credit is subject to the same conditions as the free charging promotion.

 

It's non-transferable, I don’t think I can even charge my daughters car or my friends X-Power, though I will try.

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Posted
37 minutes ago, JBChiangRai said:


LOL, my 30,000 THB credit is subject to the same conditions as the free charging promotion.

 

It's non-transferable, I don’t think I can even charge my daughters car or my friends X-Power, though I will try.

 

Yea...if that Bt30K was earned under below BYD promotion from reading the details it sure looks like the privilege will be linked to the VIN number of a BYD vehicle "you" own as proved by ownership document (i.e., vehicle bluebook).    And I think there have been similar promotions which also allowed charging credit for "up to 3 BYD vehicles" a person can prove he owns.  

 

https://www.reverautomotive.com/en/news/friend-gets-friend-campaign

 

image.png.b5954bafb7a6c64ced180163b3caba3e.png

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Posted

In a couple of weeks we need to drive to a very small place in the middle of nowhere Chaiyaphum called Bamnet Narong from our home in Jomtien. My parents in law have low power supply so the plug in charger may not work. There are no chargers for our byd dolphin within about 100 kms looking at many apps. 

 

Does anyone know the best way round this problem or have any tips. This will be our longest trip by miles since we bought it. The apps don't seem to work very well and I can't read Thai (wife can but doesn't drive).

 

We're limited to ptt or pea chargers so far, as others won't work with my Bkk bank card. There are one or two MG chargers I've seen on the apps. Is it possible to open an account? 

Posted
1 hour ago, Brightonman said:

In a couple of weeks we need to drive to a very small place in the middle of nowhere Chaiyaphum called Bamnet Narong from our home in Jomtien. My parents in law have low power supply so the plug in charger may not work. There are no chargers for our byd dolphin within about 100 kms looking at many apps. 

 

Does anyone know the best way round this problem or have any tips. This will be our longest trip by miles since we bought it. The apps don't seem to work very well and I can't read Thai (wife can but doesn't drive).

 

We're limited to ptt or pea chargers so far, as others won't work with my Bkk bank card. There are one or two MG chargers I've seen on the apps. Is it possible to open an account? 

You should have no problem charging at their house.  Max draw of your charging cable is probably only 2-3000w.  I believe it will still work, just may take a bit longer.  Sure I'll be corrected if wrong.

 

There's two @ ~25 & 42 kms away from PoPo station (PEA) and also have two others @ ~70 kms away.  Along with a few ~100 kms away.  

 

How much driving do you plan on doing while there ?

 

NO ... Unless an MG, you can't open an account with them.

 

No really seeing a problem for you ...  BYD Dolphin has a WLTP range of 427 kilometers.

 

That's ~300 kms with a 30% reserve.

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Posted

I haven't found the popo station you mentioned but will try to find it. 

It's hard to know how much we'll be driving but we would like to go fishing and visit family. We'll probably have to cut down. We get 410km range so we'll probably have to play it by ear 

Posted
1 hour ago, Brightonman said:

In a couple of weeks we need to drive to a very small place in the middle of nowhere Chaiyaphum called Bamnet Narong from our home in Jomtien. My parents in law have low power supply so the plug in charger may not work. There are no chargers for our byd dolphin within about 100 kms looking at many apps. 

 

Does anyone know the best way round this problem or have any tips. This will be our longest trip by miles since we bought it. The apps don't seem to work very well and I can't read Thai (wife can but doesn't drive).

 

We're limited to ptt or pea chargers so far, as others won't work with my Bkk bank card. There are one or two MG chargers I've seen on the apps. Is it possible to open an account? 

From googling Bamnet Narong to find it on a map, it appears from looking at the PTT and PEA charging apps PTT has 3 chargers and 1 PEA charger in your general area.

 

Your portable chargers should work fine on any 3 prong outlet that can provide at least 10 amps....but it will need to be a 3 prong type outlet....that is, have a hot line, neutral line, and earth line.  If no earth line then the charger will probably error/will not charge.  A lot of outlets in Thailand, while having 3 holes for a 3 prong plug do not have an earth line connected to the earth hole....instead, just a hot and neutral line are connected to the socket.  However, there is a way to still use the portable charger requiring an earth line on a two hole socket (i.e., only have a hot and neutral connection) but it's a little technical.

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Posted
1 hour ago, Brightonman said:

In a couple of weeks we need to drive to a very small place in the middle of nowhere Chaiyaphum called Bamnet Narong from our home in Jomtien. My parents in law have low power supply so the plug in charger may not work. There are no chargers for our byd dolphin within about 100 kms looking at many apps. 

 

Does anyone know the best way round this problem or have any tips. This will be our longest trip by miles since we bought it. The apps don't seem to work very well and I can't read Thai (wife can but doesn't drive).

 

We're limited to ptt or pea chargers so far, as others won't work with my Bkk bank card. There are one or two MG chargers I've seen on the apps. Is it possible to open an account? 


Indeed you appear to be out in the sticks, the nearest PEA charger at Chatturat appears to be out of order ( according to google maps info but not on other apps so who knows ? ) so nearest would be Chaiyaphum.

Unless there’s a PEA office nearby in which case there is a chance they have a charger, PEA Bamnet Narong doesn’t appear to have a charger as only open office hours but there might be another nearby, they don’t appear on the PEA Volta app unfortunately.

 

From my experience your BYD supplied emergency charger will not work if there is no earth cable fit to the socket. 3rd party chargers are available from Lazada to overcome this but will set you back around 3,500 baht !

Posted

Thanks guys for your quick replies.

In laws might have 10 amps max. But definitely no earth. Perhaps I can do a temporary one if I take some cable with me 

 

 

 

Posted
1 hour ago, Brightonman said:

In a couple of weeks we need to drive to a very small place in the middle of nowhere Chaiyaphum called Bamnet Narong from our home in Jomtien. My parents in law have low power supply so the plug in charger may not work. There are no chargers for our byd dolphin within about 100 kms looking at many apps. 

 

ask your in-laws if someone in their area has an ev and a wall charger. maybe they'd be willing to let you charge your car if it's really necessary ...

Posted
51 minutes ago, Brightonman said:

Thanks guys for your quick replies.

In laws might have 10 amps max. But definitely no earth. Perhaps I can do a temporary one if I take some cable with me 

 

 

 

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