Paul's 90Ah conversion

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Paul's 90Ah conversion

Hi Alberto, you may post by answering here, all yours.
;-)

electricatalan
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Re: Paul's 90Ah conversion

Ok , so first.My name is Albert, I live in Barcelona and I love the torque power of the VX-1.The problem is the well known "batteries" of the Vx-1.Well , like "The Laird" said it is not exactly the "batteries" , its the non-existent BMS or any equalization device that balance the voltage in those cells.The think is , that I'm looking to modify , a used nimh vectrix , and convert it to lithium.But then I realize that the peak amp needed is too high(270A) and I declined that idea.Soo if you put some CALB batteries on it , you can't accelerate like it has cause the amps you take from the batteries are too high and then the voltage decrease seriously till the point that the cells dies.This thing is partly solved , with the cycle analyst telling you the voltage in real time , and avoiding the drop in voltage.Well it may be ANOTHER WAY.In fact , this is not my idea , its from Paul from melbourne.He converted his vectrix on 2011 with and hybrid nimh and lithium battery.HYBRID you say?YEAH , Hybrid.

Take a look: http://www.evalbum.com/4465

His Vectrix has a 11,7 kwh battery , with a top range of 310 Km at 60 kmh .And a 180 km range with a top speed of 100 kmh.
His Vectrix has 34 modules at 3,7 volts and 90ah ( 45 x CGR18650CG + 3 NIMH batteries) total 1575 lithium cells plus 105 nimh cells.
The price of the conversion is only 2400EUR.( he claims that there's no need to put some management electronics or any bms , only a voltimeter).

¿What do you think?

He puts the nimh cells on top each module to balance the cells.

And lastly but not less important , forgive my english.

Aircon
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Re: Paul's 90Ah conversion

Paul did my conversion with those batteries almost a year ago, but only 60Ah. I preferred to save the money and weight because I'm NEVER going to do a 200km round trip. I've done 140km carefully, but 120km is easy and 100km you don't even consider riding style and go two up.

My original charger works, thanks to The Laird's software.

I wish I'd done it earlier.

electricatalan
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Re: Paul's 90Ah conversion

I don't know if the anterior message has disapeared.

Wel tells us more about the conversion.The paul conversion is only 3200 USD?where did he get those cells, are they really Panasonic?Where is the bms?Is that conversion safe?It's easy to perform?Can you tell Paul ( lithium vectrix) to post some info on how he did it.We are intrigated about the fact that he does not use BMS.

BigTony
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Re: Paul's 90Ah conversion

I Love this Idea,
I love the Granularity and intrinsic balancing built in with the NMHIs
But

I just can't seem to grasp the pricing "1575 Panasonic CGR18650CG + 105x 1.25v 3.0Ahr NiMH cells" for $3200AU$.

Firstly Panasonic seem to list this cell at 2.25Ahr not 3Ahr.
Even ex GST (10% in Oz), this is less than $2 per LiIon cell, The best pricing I have seen for these cells wholesale is nearly $5.00US$ per cell.
Then there is the 105 NMHI Balancing cells (very smart Idea), The best I can find these for is around $2.50AU$

So there is

1575x$5 = $7850
+
105x$2.5 = $262.50

This is over $8K in anyone's money.

To make this for $3200 you would need an average cell price of $1.90
I must be on the wrong web pages, I love this Idea but I just can't seem to grasp the economics.

Aircon
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Re: Paul's 90Ah conversion

I Love this Idea,
I love the Granularity and intrinsic balancing built in with the NMHIs
But

I just can't seem to grasp the pricing "1575 Panasonic CGR18650CG + 105x 1.25v 3.0Ahr NiMH cells" for $3200AU$.

Firstly Panasonic seem to list this cell at 2.25Ahr not 3Ahr.
Even ex GST (10% in Oz), this is less than $2 per LiIon cell, The best pricing I have seen for these cells wholesale is nearly $5.00US$ per cell.
Then there is the 105 NMHI Balancing cells (very smart Idea), The best I can find these for is around $2.50AU$

So there is

1575x$5 = $7850
+
105x$2.5 = $262.50

This is over $8K in anyone's money.

To make this for $3200 you would need an average cell price of $1.90
I must be on the wrong web pages, I love this Idea but I just can't seem to grasp the economics.

For the conversion, Paul charged me less than $AU3,000.00 including labour, parts, materials and the batteries. He also fitted an external charging point, so that if my charger packs up, the plug is there to use something else. So far, my charger has been fine though. I live in Melbourne where he does, though....so there was no shipping or travelling involved.

LithiumVectrix
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Re: Paul's 90Ah conversion

Hi Group,
I converted my Vectrix to Li-Ion using Panasonic Li-Co 18650 cells several years ago. The bike is still being used and has done 32,000 Km. I did my research and built smaller test batteries for Ebikes before the 90 Amp/Hr batteries for the Vectrix. LiFePO4 has different voltage range and charge characteristics than Li-Co cells. LiFePO4 require individual cell monitoring, especially during charging as cells will spike in voltage when they reach full charge. The voltage will rise to 3.45 at full charge and then quickly over 4.0 volts where upon the cell will be damaged. Li-Co have a safer overcharge characteristic, the voltage rising progressively over 4.20 volts.
The BMS used on LiFePO4 conversions is complex, expensive and usually the source of battery destruction due to BMS failures. LiFePO4 are 35% heavier and larger than Li-Co. This has caused the extra complexity of bike modifications and the lower weight reduction of LiFePO4 conversions.
The Vectrix design has the following protections built in when using the Lairds Li-Ion software. Maximum pack charge 147 volt. Maximum pack discharge 115 volts. As long as the pack remains balanced the cell voltages are within safe limits. The Panasonic 18650 cells are manufactured to a high standard and I have found them to be consistant. The Ni-Mh cells must be premium quality as high leakage in these cells could unbalance the pack. I use Sony or Panasonic industrial standard cells. Aircons bike has the 2nd version of my balancing and other components have been fitted to maintain balance. I have just finished another bike which has a 3rd design. The 3.0 Amp/Hr you quoted is for the Ni-Mh cells. The Li-Ion I have conservatively rated at 2.0 amp/Hr giving 90 Amp/Hr of Li-Ion and 3.0 Amp/Hr of Ni-Mh. The source of my cells is confidential as I am able to obtain at a lower price. I have limited supply and I also manufacture battery packs for other types of vehicles.
I have increased the price of my conversions since Aircons but not by much. I will be listing a 60 Amp/Hr Vectrix for sale soon and it will probably go on bikesales.com for about $6500.

Aircon
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Re: Paul's 90Ah conversion

Hi Group,
I have increased the price of my conversions since Aircons but not by much. I will be listing a 60 Amp/Hr Vectrix for sale soon and it will probably go on bikesales.com for about $6500.

a price increase in 12 months is fair, surely! It transformed my Vectrix into a properly usable machine...and as I keep saying, I wish I'd done it earlier.

electricatalan
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Re: Paul's 90Ah conversion

So the battery supports 270A continuous discharge?I had seen panasonic chinese importers at the range in price 2usd to 5 usd( 2200 mah to 3800 mah).So it's cheap either.
Vectrix lithium, do you assembly and sell the packs wolrdwide?Can you made a tutorial or a document , to do your conversion diy or is a secret?

The nimh + li configuration , sounds like the hybrid battery configuration that are planning at tesla for the model c.

Thanks.

LithiumVectrix
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Re: Paul's 90Ah conversion

The batteries I used are Panasonic CGR18650CG which are rated at 2C continuous and 4C intermittent. These batteries have been used in many commercial electric vehicles. The most well known being the Tesla Roadster. Spec are available on the internet. I have measured the intermittent current consumption of the VX-1 at 230 amps at full acceleration. Panasonic make many different 18650 batteries rated from the 1.1 Amp / Hr for power tools to the long range 3.2 Amp / Hr used in the Tesla Model S. I have already explained the design of the Li-Ion - Ni-Mh battery I used in my first VX-1 conversion both on this site and EV album. It is simple and no secret. I don't ship overseas.
I am a committee member of the " ATA Melbourne EV Branch". Our guest speaker at last months meeting was an Mechanical Engineer who works for Toyota and previously worked for Tesla Motors.
This is our Facebook page. https://www.facebook.com/groups/ev.melb/
There are posts of interest to EV Enthusiasts.
We have a Youtube page that you can watch previous speakers.
http://www.youtube.com/user/ATAMelbourneEVGroup
We are currently organising an EV expo at Swinburne Hawthorn, Melbourne on Sunday 23rd February 2014.
https://www.facebook.com/events/742788465749120/
I have just listed my latest conversion on EV album. This bike has electronic balancing of the battery and does not use the characteristics of Ni-Mh in its implementation. This has saved 7 Kg of weight.
http://www.evalbum.com/preview.php?vid=4802
This is a further development and I won't give detais on this new design.

antiscab
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Re: Paul's 90Ah conversion

The Vectrix design has the following protections built in when using the Lairds Li-Ion software. Maximum pack charge 147 volt. Maximum pack discharge 115 volts.

The charger voltage limit can be pretty much whatever you ask for, upper limit is ~180vdc (limitation is the 200V caps on the output, switching devices are 300V IGBT's)

the lower discharge voltage limit is 108V for the newest versions of MC firmware (all the 68mph versions), and ~95vdc for the old firmware versions

68mph firmware versions have red battery light come on when voltage falls below 115v at power levels below ~5kw (IIRC)
62mph firmware versions have red battery light come on MC is operating in low voltage limit, and latches on after a set time operating in low voltage limit

neither version of firmware will stop you from reversing a cell in a pack that is unbalanced at the bottom

The MC firmware versions have yet to be hacked

As long as the pack remains balanced the cell voltages are within safe limits.

This is true for all battery types

That's actually easier to achieve with LiFePO4 because self discharge isn't low, its 0 - you only need to balance once

Main problem is the ESD charger that the 2007 era Vectrix were shipped with has a catastrophic failure mode that causes it to charge forever with no voltage limit.
Curiously it so far has only occured on nimh bikes (I suspect the temp sensors put garbage onto the CAN bus and the charger locks up, but I can't reproduce the error to confirm- it's intermittent)

Any battery you use that can't dissipate 1500W continuously needs a way of shutting down the charger in case this happens (even a big watchdog timer is sufficient)

The other option is replacing the charger with a TC Charger, but then getting it to fit is a pain

Out of curiosity, what are you using to connect the cells together?
A capacitive discharge spot welder or an IGBT inverter unit?

Matt

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
Vectrix 60Ah Lithium Tyres Fuel Registration Insurance cycle analyst 2 x TC Charger & MC
conversion

antiscab
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Re: Paul's 90Ah conversion

I realize that the peak amp needed is too high(270A) and I declined that idea.Soo if you put some CALB batteries on it , you can't accelerate like it has cause the amps you take from the batteries are too high and then the voltage decrease seriously till the point that the cells dies.

Even the old 40Ah thunderskys can take 235A discharge - it's only peak, the Vectrix motorcontroller doesn't have sufficient cooling to maintain that power output continuously.
40Ah cells only sag to 2.8V @ 230A

230A isn't really that high to be honest

The highest continuous discharge I have ever seen on a vectrix was 110A, that was uphill in the rain at 70mph
I maintained that for 30 mins before I ran out of road

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
Vectrix 60Ah Lithium Tyres Fuel Registration Insurance cycle analyst 2 x TC Charger & MC
conversion

LithiumVectrix
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Re: Paul's 90Ah conversion

Hi group,
I have posted enough details about this conversion. I researched and developed my solution. I know it works. I guarantee my work. Members of this forum asked me for details about it. Electric vehicles are cool and I enjoy riding my Vectrix. I hope you can keep your Vectrix bikes going and spread the good word about EVs.
There is an old joke that is so true.
What is an expert. It's a drip under pressure.

allanbairstow
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Re: Paul's 90Ah conversion

Hi, First of all, thanks for taking the time to enlighten us with your jaw dropping conversion. I am in the UK and I want to do the same conversion (I'm a competent DIY'er). I can't find detailed instructions on how you did this. Are there any instructions, videos, etc ? Or is it just the links you provided with the specs on it ? I would love to be able to get 190 mile range but I need some guidance. Keep up the great work.

Electric traction is the future.

antiscab
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Re: Paul's 90Ah conversion

If you feel like taking a chance with leaf cells, around 120Ah of these may be possible to bolt together:

http://www.ebay.com.au/itm/251359065474?ru=http%3A%2F%2Fwww.ebay.com.au%2Fsch%2Fi.html%3F_sacat%3D0%26_from%3DR40%26_nkw%3D25135...

shipping could be interesting though

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
Vectrix 60Ah Lithium Tyres Fuel Registration Insurance cycle analyst 2 x TC Charger & MC
conversion

LithiumVectrix
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Re: Paul's 90Ah conversion

The Vectrix design has the following protections built in when using the Lairds Li-Ion software. Maximum pack charge 147 volt. Maximum pack discharge 115 volts.

Antiscabs Answer
The charger voltage limit can be pretty much whatever you ask for, upper limit is ~180vdc (limitation is the 200V caps on the output, switching devices are 300V IGBT's)

the lower discharge voltage limit is 108V for the newest versions of MC firmware (all the 68mph versions), and ~95vdc for the old firmware versions

68mph firmware versions have red battery light come on when voltage falls below 115v at power levels below ~5kw (IIRC)
62mph firmware versions have red battery light come on MC is operating in low voltage limit, and latches on after a set time operating in low voltage limit.

LithiumVectrixs reply
The figures I have quoted are for the ESD charger with Laird 60AHLION03.HEX firmware installed. This software programs the charger for 147 volt maximum charge and 115 volts fully discharged. The ESD charger is switchmode and can operate at other voltages with different firmware. With this conversion, this is the suitable firmware.

LithiumVectrix
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Re: Paul's 90Ah conversion

The MC firmware versions have yet to be hacked.

LithiumVectrix reply.
The firmware for the motor controller has been hacked. mc1014b.hex. This has been done by The Laird and installed in several bikes. If you ask The Laird he will let you use it.

LithiumVectrix
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Re: Paul's 90Ah conversion

As long as the pack remains balanced the cell voltages are within safe limits.

That's actually easier to achieve with LiFePO4 because self discharge isn't low, its 0 - you only need to balance once

LithiumVectrix answer : Balancing a battery once at installation will not keep the pack balanced during its use. The pack will become progressively unbalanced during use due to inconsistancies in internal resisitances and cell capacities throughout the pack. The BMS supplied by EV Works has balancing electronics built into each module. This rebalances the pack while recharging.
This progressive unbalance of cells within a pack applies to all lithium battery chemistries equally and they all have a self discharge or leakage current of near 0.

martinwinlow
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Re: Paul's 90Ah conversion

If you feel like taking a chance with leaf cells, around 120Ah of these may be possible to bolt together:

http://www.ebay.com.au/itm/251359065474?ru=http%3A%2F%2Fwww.ebay.com.au%2Fsch%2Fi.html%3F_sacat%3D0%26_from%3DR40%26_nkw%3D25135...

shipping could be interesting though

Looks like they are made to fit in a Vectrix. 1cm narrower and 3cm shorter than the stock V's battery tray. 15 of them would give 126V @60Ah and only be 3/4 of the battery tray long - and weigh only 56kg - AND only cost only $1700! If nothing else, this shows what you can do with modern battery tech.

Regards, Martin Winlow
Isle of Colonsay, Scotland
evalbum.com/2092

MEroller
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Re: Paul's 90Ah conversion

LithiumVectrix answer : Balancing a battery once at installation will not keep the pack balanced during its use. The pack will become progressively unbalanced during use due to inconsistancies in internal resisitances and cell capacities throughout the pack. ... This progressive unbalance of cells within a pack applies to all lithium battery chemistries equally and they all have a self discharge or leakage current of near 0.

Well well, we now have completely contradictory test results by a seasoned Lithium cell tester: You can see the important segment in the most recent issue of EVTV, here, from about 0:53:28 onwards:
EVTV Friday Show December 13, 2013

My rides:
2017 Zero S ZF6.5 11kW, erider Thunder 5kW

LithiumVectrix
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Re: Paul's 90Ah conversion

Thanks for posting the segment on EVTV Friday Show. I am heavily involved in EV development and building from the enthusiast area. I have worked many vehicles. The statement I posted is true and well known among the builders of battery systems for vehicles. I am encouraged to see that this is becoming less of a problem as battery manufacturing becomes more consistent. The test shown on EVTV is flawed and does not replicate the use of a battery in a vehicle. There are 2 problems.
The first is that they did not fully charge the batteries to 100% constant current constant voltage. If you watch you will notice cell 5 is out of balance and would be progressively damaged each time the battery is charged to 100%. This would have caused premature failure of the cell 5 and therefore the whole pack.
The second thing they missed is that in a vehicle the battery is discharged under heavy load during acceleration and high speed cruising. They did not replicate these conditions. It is during these conditions that the uneven internal resistances of the cells causes uneven heating, uneven voltage drops and causes the cells to imbalance through the pack. Repeated high peak or and continuous discharge will build up imbalances through the pack. The electronic balancers that I use in my Vectrix Li-Ion battery packs produce small balancing currents of 5 - 20 ma, which I have found sufficent to keep the Panasonic cells used balanced up to end of life.

Johnny J
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Re: Paul's 90Ah conversion

LithiumVectrix, there is a thing I have been struggling to understand, in Panasonics own document: http://www.panasonic.com/industrial/includes/pdf/ACA4000CE254-NCR18650A.pdf it states that only after 300 charges the capacity of their battery goes from 3100mAh to 2300mAh.
This is only with 1C discharge rate, but they do go down to 2,5V which is quite low.

How does this translate into real world performance, I mean Tesla are also using these cells?
It seems this kind of battery has a much shorter life span than LiFePo4.

LithiumVectrix
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Re: Paul's 90Ah conversion

Hi Johnny,
The batteries that I have used in my conversion is Panasonic CGR18650CG. This battery is rated by Panasonic at 500 cycles 75% capacity end of life. I have not said they will last as long as LiFEPO4. In real life, I have done 32,000 Km on my bike. Last weekend I rode from Croydon Hills to Geelong, Australia and back. This was a trip of 230 Km. The pack is now 2 1/2 years old. I have enjoyed many benefits from my conversion but I don't expect long life will be one of them.

MEroller
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Re: Paul's 90Ah conversion

I think I could "downgrade" my Emsiso BMS to only stop further dicharge when single cells drop below 2.3V under load and to stop the charger when a single cell goes above 3.65V, and disable the balancing by programming it to a threshold voltage delta of 500mV instead of 5. Like this I could bottom-balance my pack and not risk overcharging single cells, all without any balancing mayhem being possible. Without charge termination when single cells get too high I would also not like to use a bottom balanced pack ...

I am still not convinced how the same number of electrons being moved through every single cell could continuously unbalance a previously blanced Lithium pack. If one cell has higher internal resitance than another - so what? It cannot "spit out" more electrons than the cell before nor after it, nor can it absorb more electrons than it's neighbors, at least during the normal charge/discharge range. That is what a series arrangement does: all cells must work in unison. As long as the pack is utilized within reasonable cell voltage limts it has no possibility to get unbalanced, with zero self-discharge and as close to 100% Coulomb efficiency as a battery can get. Single cells may be stressed slightly higher due to higher individual C-rate, may suffer slightly higher voltage drop then other cells with lower impedance, but a current is a current is a current, from one end of the back to the other.

I would like to hear a sound physical/chemical explanation how pack imbalance could occurr in a LiFePO4 pack :-)

My rides:
2017 Zero S ZF6.5 11kW, erider Thunder 5kW

LithiumVectrix
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Re: Paul's 90Ah conversion

You were wondering where the energy goes in a series string of batteries and why it would develop imbalance? The cells that have the highest internal resistance looses the most energy. This energy is lost as heat. Your cells with the highest internal resistance will progressively fall in voltage over use and progressively unbalance the pack. All commercial BMS have a balance function, usually top balancing. They also have over and under voltage detection. LiFePO4 cells have a different voltage range and overcharge characteristic than the other lithium chemistries. They require a BMS with overvoltage protection to be able to charge to 100% capacity. This is due to the voltage of individual cells rising above safe levels as the pack approaches full charge. My design will not work with LiFePO4 as indivdual cell monitoring is required during charging. It works reliably with LiCo, LiMn2O4 and LiPo.

MEroller
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Re: Paul's 90Ah conversion

Thanks, I know why LiFePO4 needs some care as to empty and end of charge voltages ;-)

Concerning your heat theory: does a cell that heats up "eat" electrons, i.e. less come out than go in within the cell string? That would effectively mean that the electrical current through the pack is reduced successively as it flows through the cells. That profoundly contradicts the electrical laws of a series string! (Always assuming no intermediate electrical leads discharge some individual cells more than others, like could occur with a BMS wired to every cell pole...)

What really happens when electrical current flows through a cell with higher resistance is that the voltage drop of that cell is higher than the voltage drop of a cell with lower resistance. But the electrical current going through the cells is EXCACTLY the same for each cell in the series string. The additional heating up thus comes from the higher voltage drop times the current going through, which if calculated in V x A equals Watts of heating energy.

State of charge however is a more or less pure Coulomb count, i.e. the number electrons moving through the cells and thus moving Lithium ions back and forth across the separator. Those electrons and ions do not care if their movement within the cell translates into more or less heat, it is the voltage drop during that transfer that causes the heat.

If it was possible for electrons to move through a cell WITHOUT moving an ion, i.e. a kind of short circuit, THEN an imbalance of that cell would ensue. But if that is physically impossible an originally balanced pack will not be able to become unbalanced during multiple charge/discherge cycles, if that is done within the operational Voltage limits of the LiFePO4 battery chemistry.

My rides:
2017 Zero S ZF6.5 11kW, erider Thunder 5kW

antiscab
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Re: Paul's 90Ah conversion
The MC firmware versions have yet to be hacked.

LithiumVectrix reply.
The firmware for the motor controller has been hacked. mc1014b.hex. This has been done by The Laird and installed in several bikes. If you ask The Laird he will let you use it.

I wish this were the case - there's a long list of mods that I would like made to *any* version of the MC firmware, biggest one being the speed limit removed, but also changes in the way the FOC code works to allow field strengthening as well as field weakening.

MC1014b.hex is an original vectrix firmware revision from 2006/2007
It is the last revision that still has the old CAN addresses, which were necessary for use with the truly ancient copy of ESD charger source code that Mik was able to get hold (from the pre-production prototype days). I later shared that copy of source code with The Laird who was then able to create new charger firmware revisions.

low voltage limit is ~100V, red battery light comes on when MC is in low voltage limit, top speed is 105kmh - for that particular version of firmware.

Matt

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
Vectrix 60Ah Lithium Tyres Fuel Registration Insurance cycle analyst 2 x TC Charger & MC
conversion

antiscab
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Re: Paul's 90Ah conversion

You were wondering where the energy goes in a series string of batteries and why it would develop imbalance? The cells that have the highest internal resistance looses the most energy. This energy is lost as heat. Your cells with the highest internal resistance will progressively fall in voltage over use and progressively unbalance the pack. All commercial BMS have a balance function, usually top balancing. They also have over and under voltage detection.

That's pretty far from accurate

Concerning your heat theory: does a cell that heats up "eat" electrons, i.e. less come out than go in within the cell string? That would effectively mean that the electrical current through the pack is reduced successively as it flows through the cells. That profoundly contradicts the electrical laws of a series string! (Always assuming no intermediate electrical leads discharge some individual cells more than others, like could occur with a BMS wired to every cell pole...)

What really happens when electrical current flows through a cell with higher resistance is that the voltage drop of that cell is higher than the voltage drop of a cell with lower resistance. But the electrical current going through the cells is EXCACTLY the same for each cell in the series string. The additional heating up thus comes from the higher voltage drop times the current going through, which if calculated in V x A equals Watts of heating energy.

State of charge however is a more or less pure Coulomb count, i.e. the number electrons moving through the cells and thus moving Lithium ions back and forth across the separator. Those electrons and ions do not care if their movement within the cell translates into more or less heat, it is the voltage drop during that transfer that causes the heat.

If it was possible for electrons to move through a cell WITHOUT moving an ion, i.e. a kind of short circuit, THEN an imbalance of that cell would ensue. But if that is physically impossible an originally balanced pack will not be able to become unbalanced during multiple charge/discherge cycles, if that is done within the operational Voltage limits of the LiFePO4 battery chemistry.

that's about the gist of it...

Most chemistries (including Lithium chemistries) have secondary reactions that go on during normal operation, that cause imbalance (nimh is the worst)

LiFePO4 is the exeption

Rickard goes in a bit more detail:
http://blog.evtv.me/2013/07/the-thrill-of-victory-and-the-agony-of-the-feet/
http://blog.evtv.me/2013/04/2177/

or watch the video here if you prefer:
http://blog.evtv.me/2012/11/cations-anions-onions-and-jackions-through-a-glass-darkly-in-the-land-of-the-motor-verks/

who of course got some of this information from this guy:
http://www.ri.cmu.edu/video_view.html?video_id=60&menu_id=387

anyway enough refernces

I did forget to mention something from the earlier talk of MC firmware

The low voltage limits are all quirks of the implementation of the MC

basically the mc1014b.hex has no actual intended low voltage limit.

it just so happens that the field weakening above 70kmh means you need a dc bus of at least 115v to over come the back emf of the motor

and at 95v, the 5 isolated 12v power supplies for the IGBT gate drivers stop working, which is why you get the busvlt low error if the voltage sags that low

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
Vectrix 60Ah Lithium Tyres Fuel Registration Insurance cycle analyst 2 x TC Charger & MC
conversion

LithiumVectrix
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Last seen: 8 months 2 weeks ago
Joined: Tuesday, January 3, 2012 - 05:29
Points: 98
Re: Paul's 90Ah conversion

Wow !!! What a questions. This one will get the Boffins going. I will answer what I can in my unique way. The energy that is lost can be simplified to the equation W=Isquared*R. Energy is lost at the electrodes during Ion exchange depending on the current and active surface area of the electrodes. This will very from cell to cell due to variations in what is measured as the internal resistance. Though really there is no resistor there. It's just measured and stated. The electric energy is converted to heat energy and dissipated from the cell.
Now theory has to be supported by research and application. It is the last two that I focus my attention on.
Example 1 : I was involved with a build of a car with a DC series motor. It used early Thundersky LiFePO4 cells. The batteries drooped during acceleration and it suffered from drifting imbalanced batteries until the BMS finally gave up and it died prematurely. This was a common experience in early years.
Example 2 : I have a friend who has built a pack for his bike out of Headway cells put together with their spacers and end plates. This battery was balanced on installation and has no electronics. He uses a cycle analyst to may sure he doesn't over discharge and recharges to about 80%. He has done a minor rebalance last month but has found that he can generally leave the pack alone.
This shows the improvement in battery manufacturing over the years.
So my answer is you can almost get away with this is you drive slowly and don't use the full capacity of the battery. It is not a pack that I would sell or warrantee.
As to the battery theory you have stated, I admit I am beaten. I am no expert and avoid being "A drip under pressure" see my previous post. Let someone else pontificate over Einstein's theory of relativity and attempt to answer the question "It could not just disappear?"

LithiumVectrix
Offline
Last seen: 8 months 2 weeks ago
Joined: Tuesday, January 3, 2012 - 05:29
Points: 98
Re: Paul's 90Ah conversion

I would publicly like to thank The Laird for supplying us with the firmware required for my Li-Ion conversion. The Laird owns a Vectrix with ESD charger and has been developing his firmware solutions in many forms over the years for this combination. We were not concerned about his sources only the solution. He has done this without asking for payment.

THANKYOU MR LAIRD.

We approached him January this year and have installed the Li-Ion firmware in 4 bikes.
Now why do we use the ESD charger? It is because of economics. A second hand Vectrix is worth about AU$1200. We are asking someone to spend $2500 - $3200 to repair it. To fit a later charger is uneconomic. All you will do is overcapitalise the bike and make it cost more than it is worth. I know about the poor design, large resistor, inadequate power supplies ect. I warn my customer not to recharge their Vectrix in high temperatures. The results we have had is 1 ESD out of 4 has blown up since the bikes were built. That was on my bike. I chose to build an external charger and only charge at home rather than replace it.

Soyouz
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Last seen: 3 years 7 months ago
Joined: Thursday, September 23, 2010 - 07:47
Points: 39
Re: Paul's 90Ah conversion

Hello,

For sure Leaf cells are designed especially for VX. It is like the bike was built around !
I could put 19 modules easily.
63 Ah * 3,7 * 19 *2 = 8,8 kWh !! Without changing any parts of the bike and with very easy access to every cells.
I just begin this conversion. I hope to get the harness that come with.
Iwill keep you informed.
Leaf cells - VX.jpg

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