Payback and Net Present Value are separate investment appraisal techniques. 
 

 

15 hours ago, watchcat said:

 

No I'm not itersted ,Why shoulud in  I be, Save the planet  or your electrict bills My guess is thage latter
 

Failed troll attempt lol.

12 hours ago, Bandersnatch said:

Payback and Net Present Value are separate investment appraisal techniques.

 

The anti EV/PV brigade like to criticize long payback times for solar, but always fail to acknowledge that Payback ignores savings made after payback has been achieved and with solar panels having a working life of 20-25 years they are ignoring a lot of savings.

 

The next line of attack is to criticize payback for not taking into account inflation claiming that future savings are worth less but again failing to acknowledge that electricity costs tend to rise faster than inflation.  Case in point we are looking at a potential 44% increase in electricity costs this year. 

 

Those of us shifting from ICE to EVs and Solar are looking at increased savings as fuel prices also rise faster than inflation. Currently the Oil Fuel Fund has accumulated losses of over 100 billion baht after subsidizing diesel, gasohol and gasoline prices a situation that is not sustainable.

 

Being an accountant I tend to be 'conservative" (with a small c) and use historic figures so as not to overstate the savings for solar and EVs 

I had an electrician fit some automatic transfer switches so I can run my refrigerator, lights, TV & Air Conditioning in my bedroom and the Water Pump from my car.

 

I will sell my 28.8KwHr of LFP batteries as using the car is a much more elegant & cheaper solution.

 

 

5 minutes ago, JBChiangRai said:

I had an electrician fit some automatic transfer switches so I can run my refrigerator, lights, TV & Air Conditioning in my bedroom and the Water Pump from my car.

 

I will sell my 28.8KwHr of LFP batteries as using the car is a much more elegant & cheaper solution.

 

Nice setup.

 

I have found that my BYD Seal is much more efficient at providing backup power than my home solar setup.

If & when they change my spinning meter for digital, I can switch over the air con in my bedroom to run from the car overnight and charge it back up from grid-tied solar set to no export.

On 7/9/2024 at 9:19 AM, KhunLA said:

Be careful ... it's addicting, me...

... started with drones

... then DIY drones

... more toys; RC cars & boats

... then ebike ... check

... on to E-MC

... then solar system ... check

... finally EV (car)

... constantly tempted to buy more, so far the addiction is under control, but it's one day at a time 

 

2 down for you ... what next 

 

It's a little off-topic, but I want to see what happens with electric powered GA aircraft.

 

As the power/weight ratio of batteries improves, as does range/charge time, I'd like to think some interesting possibilities exist.

 

Take a generic Cessna 172 for example. Max take off weight is just under 1,050 kg. Of that, full tanks of fuel (c. 150 litres) are about 110 kg. Lycoming O-320 engine weighs about 125 kg. Add another 10-20 kg for oil, filters, fuel lines etc. So traditional engine + fuel is about 250 kg and gives about 4 hours endurance on full tanks.

 

All electric would be quieter, much easier for fuel management (the number of GA accidents caused by fuel exhaustion is significant), make for simpler weight and balance calculations, remove need for engine leaning, better high density altitude performance since power doesn't come from burning a fuel/air mix, no risk of shock cooling, carb icing, fuel contamination and could deliver 100% power instantaneously etc 

 

A Lycoming O-320 is a great engine. May be 80 year old design but will run happily at a cruise power setting for hours (say 75% / around 2,400 rpm). But a 1,000 hour TBO schedule puts you on the hook for maybe USD 30K to overhaul. 

 

With an electric-powered aircraft, maybe it would also be possible to integrate trickle charge solar paneling into the wings?

 

Of course it's not all 'electric good'. I don't know how ambient air temp changes would impact battery performance, especially sub-zero. And there could be considerable CG issues. 

 

But the possibilities - at least to me - seem very exciting.

 

 

 

3 hours ago, JBChiangRai said:

I had an electrician fit some automatic transfer switches so I can run my refrigerator, lights, TV & Air Conditioning in my bedroom and the Water Pump from my car.

 

I will sell my 28.8KwHr of LFP batteries as using the car is a much more elegant & cheaper solution.

 

 

And reducing the life time of your car battery??? Have you thought about that 

22 hours ago, JBChiangRai said:

 

Absolute nonsense.

Well, up to you. I did my calculation and it's not worth using solar panels on my house. Sad but true. 

Btw, I own an EV and charge it using TOU tariff from MEA. 

ROI of solar with battery storage was between 10 and 15 years. Simply not worth it. 

20 hours ago, UWEB said:

If you have an EV Car and charging at home from Solar it will heavy reduce the ROI for a System.

Not if you are using TOU

24 minutes ago, CLW said:

And reducing the life time of your car battery??? Have you thought about that 

 

My EV battery is guaranteed for 8 years and I think that may be about to increase if BYD follow MG's lead.

 

20 minutes ago, CLW said:

Well, up to you. I did my calculation and it's not worth using solar panels on my house. Sad but true. 

Btw, I own an EV and charge it using TOU tariff from MEA. 

ROI of solar with battery storage was between 10 and 15 years. Simply not worth it. 

 

It depends where you buy it from.  I installed 28.8KwHrs of battery and 22kw of panels etc and my ROI is about 5 years.  If you just go grid-tied no export (which is what I would recommend for anyone with TOU meter) then your ROI could well be under 3 years.

 

 

19 minutes ago, CLW said:

Not if you are using TOU

 

A TOU meter shortens your ROI time with grid-tied systems.

38 minutes ago, CLW said:

And reducing the life time of your car battery??? Have you thought about that 

 

My car’s battery is designed to push a 2 tonne car at over 100km/hr for 160,000km and after that it is warrantied to still have over 70% capacity left. By comparison when I use it for my home backup I am drawing only a few hundred watts. How is that going to significantly shorten the battery lifespan compared to driving it?

 

I can power my house all night and only use the equivalent of 50km or range.

 

You have to crunch the numbers before making sweeping statements like  "reducing the life time of your car battery"

 

2 hours ago, CLW said:

Not if you are using TOU

Better to go back to School and start learning to read, I was talking about Solar. Not TOU.

On 7/11/2024 at 12:20 AM, vinny41 said:

Starting in Thailand, MG has announced that they will be starting a program wherein EV models will have a lifetime warranty for 3 critical components of the EV drive system: the high voltage battery assembly (HV Battery Assy), the electric drive unit (EDU), and the power electronic block (PEB). That practically covers all the major components of the drive system, and provides unprecedented peace of mind for EV owners.

Initially, MG Thailand will start offering this for four of their existing models: the MG4, the MG Maxus 9, the MG Maxus 7, and the MG Cyberster. MG says the warranty will be retroactive to customers in Thailand who already own any of the 4 MG models mentioned.  Critically, they say that the warranty carries over even when the ownership of the vehicle has changed. The warranty is attached to the vehicle, not the first owner.

https://www.autoindustriya.com/auto-industry-news/gamechanger-mg-has-begun-to-offer-lifetime-ev-battery-warranty.html

With a lifetime warranty , does it NOT matter now having an NMC battery car and charge to 100% daily and not worry on longevity ( lFp battery had the advantage of charging 100 versus NMC to only 80 % to prolong longevity of battery wear. 

 

 

On 7/11/2024 at 12:20 AM, vinny41 said:

Starting in Thailand, MG has announced that they will be starting a program wherein EV models will have a lifetime warranty for 3 critical components of the EV drive system: the high voltage battery assembly (HV Battery Assy), the electric drive unit (EDU), and the power electronic block (PEB). That practically covers all the major components of the drive system, and provides unprecedented peace of mind for EV owners.

Initially, MG Thailand will start offering this for four of their existing models: the MG4, the MG Maxus 9, the MG Maxus 7, and the MG Cyberster. MG says the warranty will be retroactive to customers in Thailand who already own any of the 4 MG models mentioned.  Critically, they say that the warranty carries over even when the ownership of the vehicle has changed. The warranty is attached to the vehicle, not the first owner.

https://www.autoindustriya.com/auto-industry-news/gamechanger-mg-has-begun-to-offer-lifetime-ev-battery-warranty.html

 

Wow....this is a big change...hopefully BYD and others will follow suit for old and new customers in order to remain competitive.  Such a warranty would definitely wipe-out a major reason some people are reluctant to buy an EV.   Below is another web article talking the MG change.

 

https://www.mgcars.com/en/NewsActivities/Detail/MG-Lifetime-Battery-Warranty

8 hours ago, Bandersnatch said:

 

My car’s battery is designed to push a 2 tonne car at over 100km/hr for 160,000km and after that it is warrantied to still have over 70% capacity left. By comparison when I use it for my home backup I am drawing only a few hundred watts. How is that going to significantly shorten the battery lifespan compared to driving it?

 

I can power my house all night and only use the equivalent of 50km or range.

 

You have to crunch the numbers before making sweeping statements like  "reducing the life time of your car battery"

 

Honestly this is really interesting for people who don't understand the unbelievable capacity these batteries have and how little impact things like AC have on them in the overall scheme of things. It is hard to compute for most people. Luckily most people refrain from making silly blanket statements....

10 minutes ago, josephbloggs said:

Honestly this is really interesting for people who don't understand the unbelievable capacity these batteries have and how little impact things like AC have on them in the overall scheme of things. It is hard to compute for most people. Luckily most people refrain from making silly blanket statements....

If the capacity is so great, why is the range so small? 

2 hours ago, Yellowtail said:

If the capacity is so great, why is the range so small? 

Not sure if that is a serious question or not. I guess not.

5 hours ago, Pib said:

 

Wow....this is a big change...hopefully BYD and others will follow suit for old and new customers in order to remain competitive.  Such a warranty would definitely wipe-out a major reason some people are reluctant to buy an EV.   Below is another web article talking the MG change.

 

https://www.mgcars.com/en/NewsActivities/Detail/MG-Lifetime-Battery-Warranty

While the move is welcome it is important that the MG owners that are affected by this change read the terms and conditions and the exclusions and understand the term of a lifetime warranty and eol as many people have different interpretations about the meaning of a lifetime warranty

On 7/19/2024 at 2:12 PM, CLW said:

Unless you can sell the electricity, solar is not financially feasible in Thailand. For the investment cost you could use grid power for approximately 15 years. 

 

Still waiting for a breakdown of your calculations for 15 year payback for solar 

 

You claim to have an EV, but no details offered as to which one.

 

Let me help you with your calculations

 

I make a saving on my previous PEA bill and powering my EVs of ฿8k a month let’s assume you save half that

 

฿4k x 180 months = ฿720,000

 

So your solar system would have to cost you ฿720,000!

 

Let’s assume you get a quote for a 10:10:10 system

 

Main Components would cost 
10,000 Watts of PV @ ฿5/W = ฿50,000
10kWh Batteries @ ฿5k/kWh = ฿50,000
10kW of Inversion @ ฿5k/kW = ฿50,000
Total = ฿150,000

 

to which you have to add ancillary items like cables, rails, clamps, breakers, combiner boxes plus fitting

 

A supply and fit quote would include mark up on your components as well but even so we are nowhere near ฿720,000

I’m calling bs on your 15 years payback

 

On 7/19/2024 at 2:12 PM, CLW said:

Unless you can sell the electricity, solar is not financially feasible in Thailand. For the investment cost you could use grid power for approximately 15 years. 

With your TOU meter and a self install, you may achieve ROI in as little as 2 years.

 

A TOU meter is a positive indication for a grid-tied system.

 

I designed my first 6kw grid-tied system myself and my usual sparky was only too happy to install it himself as he wanted to learn about Solar. 
 

A 3Kw grid-tied system could cost you as little as 50,000 baht, and save you 2,500 baht per month on your TOU meter.

1 hour ago, JBChiangRai said:

A 3Kw grid-tied system could cost you as little as 50,000 baht, and save you 2,500 baht per month on your TOU meter.

If 3 or 5kW system installed specifically for the EV, and home during the day, ROI would be <1-2 yrs if driving 20k kms locally.   That would save 54k baht per year, and petrol (91) is now more expensive than when I did those calculations.   Comparing cost of MG ZS ICE vs BEV, which I owned/own both.

 

That's our potential saving charging the ZS at home on solar, if only driving locally.

 

ROI isn't even considering the savings off the house use of electric from PEA/MEA.   Just another uninformed post from an uninformed member.  Why do they bother ... 

 

Our 8kWh system with 20kWh of ESS will have a ROI from <4 years to 6 years, depending how much we abuse the AC and drive unnecessarily.  Are system wasn't exactly inexpensive, or DIY.

 

Real life experiences vs BS 

Anyone replace their 12v lead acid battery with a lithium one yet ?  Where did you source the battery ?

 

TIA

4 minutes ago, KhunLA said:

Anyone replace their 12v lead acid battery with a lithium one yet ?  Where did you source the battery ?

 

TIA

I replaced the batteries on my daughter’s Kawasaki Ninja 400 and Honda Scoopy with Lithium batteries that have an inbuilt BMS. A friend of mine was importing them (he got my solar ESS too) he killed himself on his motorcycle and I was left with all his stock to dispose of. I have seen them advertised on Lazada

53 minutes ago, JBChiangRai said:

I replaced the batteries on my daughter’s Kawasaki Ninja 400 and Honda Scoopy with Lithium batteries that have an inbuilt BMS. A friend of mine was importing them (he got my solar ESS too) he killed himself on his motorcycle and I was left with all his stock to dispose of. I have seen them advertised on Lazada

This is for the MG ZS, as may need to replace.  63Ah is in it now.  Seeing lead acid GS brand (LN2-DIN65 DL EFB) for <฿3k online.  No local dealer, and would prefer to upgrade to a lithium.

56 minutes ago, KhunLA said:

Anyone replace their 12v lead acid battery with a lithium one yet ?  Where did you source the battery ?

 

TIA

I'm sure you are aware the charging profile/100% charged level for a 12V flooded lead acid, 12V absorbed glass mat (AGM) , and 12V lithium type battery are different.   And of course when saying 12V battery it means "nominal" 12V as the actuall voltage when 100% charged for a flooded 12V battery is approx 12.7V, AGM 13.0V, and lithium 14.4V.     See below chart that gives an overview of various voltage levels. 

 

Additionally, there are different types of AGM batteries---some designed for high Cold Cranking Amperage (CCA) needed to start ICEV....some designed for deep cycle operation where the CCA is lower but can be cycled deeply like for longer running time and running electrical applicance, a boat electric motor, etc.  If going the AGM route just be sure to get one geared for starting vehicles if used on an ICEV....but since you are looking at a replacement battery for you EV where high cranking power is not needed a deep cycle AGM should be better than a high CCA AGM battery....but either AGM type should be fine for an EV....and better than a flooded 12V battery....howevver,  an AGM will cost more than a flooded battery.  

 

The charging profile (i.e.., Constant Voltage/Constant Current profile) for a 12V flooded and AGM are different but only by a little bit.  Switching from a flooded 12V battery to AGM 12V battery is commonly done on vehicles since the charging profile is similar.  But if using a lithium type battery it will never get fully charged to 100% if the EV's DC-DC convertor circuit which charges the 12V battery is set for a lead acid type battery.....geared to fully charge to a voltage "less" than what a lithium type battery needs.  You could install a lithium type battery and your EV which is programmed to charge a 12V lead acid type battery and therefore the lithium type battery would never be fully charged. 

 

Just switching from a lead acid type battery to a lithium type battery does not automatically mean it's a good idea...will result in longer battery life...will result in more Amp-Hour running time UNLESS the charging circuit/profile is also designed for the battery type being used.

 

https://www.renogy.com/blog/expectations-vs-reality-making-sense-of-battery-voltage-percentages/

 

27 minutes ago, Pib said:

I'm sure you are aware the charging profile/100% charged level for a 12V flooded lead acid, 12V absorbed glass mat (AGM) , and 12V lithium type battery are different.   And of course when saying 12V battery it means "nominal" 12V as the actuall voltage when 100% charged for a flooded 12V battery is approx 12.7V, AGM 13.0V, and lithium 14.4V.     See below chart that gives an overview of various voltage levels. 

 

Additionally, there are different types of AGM batteries---some designed for high Cold Cranking Amperage (CCA) needed to start ICEV....some designed for deep cycle operation where the CCA is lower but can be cycled deeply like for longer running time and running electrical applicance, a boat electric motor, etc.  If going the AGM route just be sure to get one geared for starting vehicles if used on an ICEV....but since you are looking at a replacement battery for you EV where high cranking power is not needed a deep cycle AGM should be better than a high CCA AGM battery....but either AGM type should be fine for an EV....and better than a flooded 12V battery....howevver,  an AGM will cost more than a flooded battery.  

 

The charging profile (i.e.., Constant Voltage/Constant Current profile) for a 12V flooded and AGM are different but only by a little bit.  Switching from a flooded 12V battery to AGM 12V battery is commonly done on vehicles since the charging profile is similar.  But if using a lithium type battery it will never get fully charged to 100% if the EV's DC-DC convertor circuit which charges the 12V battery is set for a lead acid type battery.....geared to fully charge to a voltage "less" than what a lithium type battery needs.  You could install a lithium type battery and your EV which is programmed to charge a 12V lead acid type battery and therefore the lithium type battery would never be fully charged. 

 

Just switching from a lead acid type battery to a lithium type battery does not automatically mean it's a good idea...will result in longer battery life...will result in more Amp-Hour running time UNLESS the charging circuit/profile is also designed for the battery type being used.

 

https://www.renogy.com/blog/expectations-vs-reality-making-sense-of-battery-voltage-percentages/

 

We were getting the '12v fault warning', and watching the  gauge monitoring it, and it was fuctuating between 11v & 14.1, and occasionally dippin below 11v, down to 10.2v.   Fault warning came on more than a few times while driving home.   Have appt at MG tomorrow, check make sure it's the battery and not the charging 'module'.  Only 21 months old, though batteries from dealers and in TH in general, do seem to be low quality.

 

Surprised how many needed replacement on past Toyotas & Mazda.  MG ZS ICE (2020) had 2 yrs / 40k kms on it when sold, and battery going strong.   Actually the same battery in the EV version, I think.

Replacement LFP batteries are designed so the BMS mimics a flooded lead acid cell.  I saw a 100 Ah one on Lazada for 6,700 baht which will probably do the job if it has the right dimensions.

8 minutes ago, JBChiangRai said:

Replacement LFP batteries are designed so the BMS mimics a flooded lead acid cell.  I saw a 100 Ah one on Lazada for 6,700 baht which will probably do the job if it has the right dimensions.

They may say they are designed to miminic a 12V lead acid battery but if the charging circuit on an EV is designed for a 12V lead acid type battery (which will be the case if the EV came with a lead acid battery) that charging circuit will charge in the 13.6 to 13.8V ballpark....below the approx 14.4V needed to fully charge a 12V lithium type battery....the lithium battery will end up charging to approx 80% of capacity.

2 minutes ago, Pib said:

They may say they are designed to miminic a 12V lead acid battery but if the charging circuit on an EV is designed for a 12V lead acid type battery (which will be the case if the EV came with a lead acid battery) that charging circuit will charge in the 13.6 to 13.8V ballpark....below the approx 14.4V needed to fully charge a 12V lithium type battery....the lithium battery will end up charging to approx 80% of capacity.

 

He has a voltage gauge on his car, most lead acid batteries on cars charge at 14.4v for some of the charge cycle.  Perhaps @KhunLA can tell us what voltage he has seen on his ZS?  I recall seeing 14.3v on the MG EP+.

 

In any event, charging to 80% capacity may not necessarily be a bad thing depending on whether active balancer or passive balancer set for a higher voltage.  It could be beneficial.