Toyota Hybrid first edition what can be done

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Toyota Hybrid first edition what can be done

Post by coulomb » Sat, 19 Nov 2011, 22:55

KDRYAN wrote: ... on what I can make out the ICE is in no way connected directly to the differential drive.

Ah, I may have misunderstood your original statement. There are two "differential drives" in a Prius. There is the standard one for distributing torque to the wheels as they corner, let's call that the "final diff drive". There is also the power split device, which also uses planetary gears, so it's much like a standard differential in operation, except that there are two inputs and one output instead of one input and two outputs (in reality, they are all input/output mechanical "terminals").

The ICE connects to the final diff drive via the power split device. In the sense that if you don't apply power (or a brake) to MG1, then it's true that there is no mechanical connection from the ICE to the final diff drive (and hence the wheels). But in normal operation, something like 72% of the torque from the ICE goes to the wheels (though MG2 can "steal" some of that by acting as a generator, or add to it by acting as a motor. That's how the Prius transmission works; torque is added at low speed and taken away at high speed by MG2, and the power goes either to MG1 or to the hybrid battery).
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Post by coulomb » Sat, 19 Nov 2011, 23:14

In case it helps some, here's a diagram of the Prius transaxle:

Image

From "ORNL/TM-2004/137: REPORT ON TOYOTA/PRIUS MOTOR DESIGN AND MANUFACTURING ASSESSMENT", J. S. Hsu, C. W. Ayers, and C. L. Coomer, Oak Ridge National Laboratory, which in turn came from a Toyota manual as stated above.

The ICE input is at the top right; the power split device is upper middle. Output from the ring of the planetary gear goes off to the standard FWD differential and CV joints at the bottom, via some counter gears.

I've posted a picture of the counter and final gears earlier:

Image

I thought it was from the same report, but I can't find it now. [ Edit: it's from Evaluation of 2004 Toyota Prius Hybrid Electric Drive System, another Oak Ridge National Laboratory report. ]

[ Edit: the top diagram uses the old terminology of "Generator" for MG1 (Motor/Generator number 1) and "Motor" for MG2. You can see that the Prius transaxle has relatively few gears, and a fair bit of the space is taken up by the two motors. ]

[ Edit2: Added URL for report ]

[ Edit3: Two more PriusChat images to put things in perspective:

Image

Image
]
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Post by antiscab » Sat, 19 Nov 2011, 23:24

coulomb wrote: I read somewhere that the power loss due to spinning the ICE is 4 kW (last post on this Ecomodder page.


Thats probably what is drawn during the first minute warm up, which the Prius will do if the battery is good enough.

So cold engine, cold transaxle, heating the emission controls, etc

Not sure how much that goes down by once stuff reaches temp

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Post by coulomb » Sat, 19 Nov 2011, 23:51

Another thought on this. I read somewhere that the NHW10 models were sold at a loss, costing perhaps 50% more than what they were sold for. It's almost impossible to know this for real, but I don't think that the 50% figure is unbelievable.

To be able to pick these cars up for under AU$1000 now, due to bizarre circumstances, is somewhat interesting to me. They're quality Toyotas, which are usually backed up by Toyota, but these were only ever sold in Japan, and only grey marketed to Australia, New Zealand, and the United Kingdom. Now the original battery packs are failing, and the packs aren't readily available here, so this opportunity comes up.

I'd guess that similar circumstances would be very rare. If as a group we can figure out a good way to turn these into usable vehicles, a lot of waste can be avoided, and some of us can end up with decent rides for not too much money.
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Post by coulomb » Sun, 20 Nov 2011, 00:40

antiscab wrote: Thats probably what is drawn during the first minute warm up, which the Prius will do if the battery is good enough.


I have another data point here:

"This is a very low-resistance state for the engine to be in, and it only takes a kilowatt or two to keep all that merrily turning."

From http://www.techno-fandom.org/~hobbit/ca ... ealth.html, about 1/3 down.

1-2 kW, if it's accurate, somehow doesn't seem so bad to me.
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Post by antiscab » Sun, 20 Nov 2011, 00:58

minimum engine speed at 100kmh is ~1000rpm

1kw of loss means an extra ~10Nm of torque that MG1 can apply in addition to MG2.

But that's all academic IMO,
with only approx 4.5kwh of usable capacity, the engine my as well be running if it has to be turning...

I can't imagine too many situations where you are traveling at 100kmh, and will use less than 4.5kwh during the journey....

For me I was more observing I could make a plug in hybrid for the same price as a normal hybrid, or even a normal car (or a cheap EV)


Matt

Edit: Freudian slip this time -> academic
Last edited by antiscab on Sat, 19 Nov 2011, 13:59, edited 1 time in total.
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Post by woody » Sun, 20 Nov 2011, 06:12

My way of visualizing the Prius drivetrain is this:
2 live rear axles from a cortina :-)
One has one wheel on each end - this represents the Prius front wheels
MG2 has driveshafts both ends - each connected to a diff pinion where the tail shaft would normally connect
On the othe live axle, the petrol Atkinson cycle engine connects where one wheel would
MG1 connects where the other would

So driving MG2 and freewheeling MG1 gives you EV / stealth mode and reverse.
MG1 can be stopped (middle gear) spinning same way as ICE (high gear) or opposite way (low gear)
In low gear, MG1 is generating, feeding power into MG2 and/or the battery pack
In high gear, MG1 is motoring getting fed power from MG2 and/or the battery pack
Other things are possible, see Wikipedia entry for hybrid synergy drive
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Post by Simon » Sun, 20 Nov 2011, 20:04

antiscab wrote: For me I was more observing I could make a plug in hybrid for the same price as a normal hybrid, or even a normal car (or a cheap EV)


Yes I keep on thinking about turning my Prius into a cheap EV. There are already lots of good elements built in with regen, dc-dc convertor, electric power steering and brakes(just add batteries Image ).
For around $7-8 thousand I think you could endup with a nice EV with an 80km range.
It would not be fast or freeway capable though..
I was kind of hoping that you were going to do it to your Prius antiscab so I would be able to follow your lead!    Image

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Post by coulomb » Fri, 09 Dec 2011, 00:28

bga wrote: For what it's worth,

I inquired about a battery pack for a prius a year or so ago. Toyota said a bit over $3K, but there are very few in stock and I didn't ask about age.

What model was that for? The NHW10s and NHW11s actually have the largest capacity packs, at around 1.8 kWh each (one 288 V nominal @ 6 Ah (though they are possibly 6.5 Ah, I can't seem to get a definitive answer [ Edit: see Note 1] ), and the other 273.6 V nominal at 6.5 Ah). By contrast, the more common NHW20 packs are 201.6 V nominal at 6.5 Ah, for 26% lower capacity. So the First Gen packs might actually be dearer, as well as possibly harder to obtain. NHW10s were never sold in Australia, so NHW10 packs are not available from Toyota Australia.

There is an after-market pack that has recently become available:

Micks Question NHW10.

This is an 8 Ah pack (33% larger capacity than original, or 23% larger if it turns out that the original packs were 6.5 Ah). It costs US$3500 plus shipping and import costs (both of these could be quite considerable). If there could be landed for say AU$4000 (it seems unlikely), and if they could be charged safely (this is more tricky than it seems; NiMH are difficult to charge correctly, and there is a risk of fire), then a "very mild plug-in hybrid" could be made.

[ Edit: Note 1: From http://www.pressroom.com.au/pressroom/s ... kit.htm#14, the capacity is 6.5 Ah. So all the Prius hybrid batteries are 6.5 Ah. ]

[ Edit2: 3/Jan/2012: The first of these to arrive in Australia has been delayed by a customs form typo, and delays with the Christmas holidays and an office move. I'll be watching this closely. ]
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Post by coulomb » Fri, 09 Dec 2011, 00:42

I have the opportunity to buy this NHW10 Prius from Suzi Auto. Graeme decided that he's too busy with the mechanical side of his business, plus several electric conversions that are in progress, so a few days after I expressed an interest in it, he offered to let me have it for about what it cost him.

I managed to get the motor running on it, using the boost inverter that the NHW10 models have. The turtle icon comes up, so the hybrid battery is intermittently good enough to start the car, but not enough to perform its normal hybrid power assist function. But it means I can probably get a one day permit to drive it home, and save a tow. Then I can determine the actual state of the hybrid pack, and consider my options.

I can take a little time to decide whether I want to take this on. At this stage, I'm leaning towards yes; it's a good opportunity to learn about this model, many of which will presumably be becoming available cheaply with hybrid battery problems.
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Post by antiscab » Fri, 09 Dec 2011, 01:43

The turtle icon means the traction battery is either low voltage, or a single (or more) stick is low on voltage.

given you had to use the 12v powered charger to bring the pack up, I would say most likely low pack voltage

What you will have to look out for is the traction battery major fault condition where the battery gets disconnected completely (main contactor opens) your top speed is ~20kmh, engine spins at 2500rpm continuously, and max torque is reduced so some hills are unclimbable.

That happens if any stick falls 1.2v below the rest (reversed cell), or the pack temperature gets too high

do you have far to drive?

btw - Enerdel cells are 30Ah, 350g, LiFePO4 and US$38/ea

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Post by antiscab » Fri, 09 Dec 2011, 01:45

Also
I bought a 650v 0.2A variable lab powersupply off ebay for $200

MW Machinery is where it came from

should be very useful for doing manual balancing

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Post by coulomb » Fri, 09 Dec 2011, 04:17

antiscab wrote: do you have far to drive?

12 km. Less than an hour at 20 km/hr Image

I sure hope I don't get hit with the 20 km/h limit. There was some running at around 2500 RPM.
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Post by coulomb » Fri, 09 Dec 2011, 04:35

antiscab wrote: Enerdel cells are 30Ah, 350g, LiFePO4 and US$38/ea

They seem too good to be true. Are they available from anywhere reliable?

Are these the ones?

http://www.alibaba.com/product-gs/43442 ... el_Li.html

Image

I wonder if the tabs are removed on these. Those strips of yellow tape don't seem original to me.
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Post by antiscab » Fri, 09 Dec 2011, 12:55

coulomb wrote:
antiscab wrote: I sure hope I don't get hit with the 20 km/h limit. There was some running at around 2500 RPM.


If you are already driving at speed when the fault comes up, your speed will fall by 1kmh/second until you are doing ~20kmh

If you turn the car off, and turn it back on, it might kick out of it for a while

those cells from alibaba are the ones I was talking about, though they are actually 450g, not 350g

Enerdel is an American company, who opened a factory in China (or maybe Korea) but lost control of it (same as what happened to A123)

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Post by jonescg » Fri, 09 Dec 2011, 17:43

coulomb wrote:
antiscab wrote: Enerdel cells are 30Ah, 350g, LiFePO4 and US$38/ea

They seem too good to be true. Are they available from anywhere reliable?

Are these the ones?

http://www.alibaba.com/product-gs/43442 ... el_Li.html

Image

I wonder if the tabs are removed on these. Those strips of yellow tape don't seem original to me.


Yes I spotted these on Alibaba too. No idea, but they pack over 200 Wh/kg. The tabs are hidden on either side of the cell under the yellow tape. 30 Ah in a cell as big as a 20Ah A123 pouch... Hmmm, I think they might be gilding the lilly.
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Post by antiscab » Tue, 13 Dec 2011, 00:45

heres another prius for sale:
http://www.ebay.com.au/itm/ws/eBayISAPI ... SS:AU:1123

probably just needs a slow recharge.....
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Post by htial » Tue, 13 Dec 2011, 03:00

antiscab wrote: heres another prius for sale:
http://www.ebay.com.au/itm/ws/eBayISAPI ... SS:AU:1123

probably just needs a slow recharge.....



I've been looking for something as a silly track car...   ...This could be it...   ...Just wish the countdown was a little longer so I could think about it some more...
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Post by Electrocycle » Tue, 13 Dec 2011, 04:25

that is about the silliest track car I could imagine!
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Post by coulomb » Tue, 13 Dec 2011, 05:59

antiscab wrote: heres another prius for sale:
http://www.ebay.com.au/itm/ws/eBayISAPI ... SS:AU:1123

probably just needs a slow recharge.....

Like many for sale ads I've read, this one says "Main battery replaced 12 months ago".

How?

My understanding is that you can't get a replacement pack from Toyota. Do they get their local garage to get a refurbished pack from New Zealand?

Or is this just a lie?

Or are they calling the auxiliary 12 V battery the "main" battery?
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Post by antiscab » Tue, 13 Dec 2011, 14:09

I'd say if the battery is flat, and thats' the reason they're selling it, they probably don't know what they're doing (or just lying)

but if you're local, worth having a look at, easy enough to jump start and let the battery charger bring the big battery up

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Post by coulomb » Sat, 17 Dec 2011, 03:28

I've been considering my options, posting to the Mark 1 Prius Yahoo group:

http://autos.groups.yahoo.com/group/Mk1 ... ssage/5536

(Note: I think that registration is required (free, but slow) for this group).

While I've been wondering about this, I was contacted by someone with an ailing NHW10 with just 41,000 km on the clock, and one of the last '10s made (2000 manufacture). It's a bit ironic that while low mileage is generally good for a car, it's probably bad for the hybrid pack. I had ideas of this Prius being the first customer for a sort of "Prius Import Rescue" business.

In the above thread, Mr Mik kindly offered to "brain dump" all he knows about the NHW10 model. He has three of them; two are daily drivers and one is a repairable writeoff that he uses for parts. He also came across four NHW10 packs for $100 some time ago, so he's got lots of cells to play with. (These are all old packs, from cars that had their packs replaced with new or refurbished NHW10 packs from Japan. So someone knew how to import replacement packs from Japan!) Unfortunately, the novelty of rejuvenating NHW10 packs has worn off for him, and there are other demands on his time, so things haven't progressed for a year or so.

As it happens, one of his daily drivers is showing the triangle and turtles, and so it needs a slow equalisation with his charger. To do that, he needs to take the front off the pack, and he had the day off today. If I'm going to start this rescue business, I'll need to know all I can about the NHW10 car, so I begged Weber for a day off from MX-lightning duties, and visited Mr Mik's "Prius Farm" today.

I certainly learned a lot today, and I'm very grateful to Mr Mik for taking the time to teach me some of the tricks he's learned. One big realisation for me is that life would be pretty miserable without the Toyota S2000 scanner, which he grabbed one of for "only" $1200. This is one of the few machines that will talk to the NHW10s, which seem to have OBD-1 ports (most cars have OBD-2 ports). Without this scanner, the only way to get the stick (strings of 6 cells manufactured into a sort of rigid tube) voltages would be with a multimeter on the ends of the sticks. I envisaged this as a fairly simple exercise, but alas, the only practical way is to take the battery box (almost the width of the car and weighing some 60 kg) out of the car, and take out the two half-packs from the removed box. This makes the "instant diagnosis" part of the business plan rather difficult.

(BTW, the readout of the S2000 scanner is all in Japanese; it's taken the NHW10 community some time to decode the menus. Fortunately, the numbers are in English, so after a while, you get to remember the sequence of numbers to get to a particular menu option.)

Mr Mik was working with a colleague from New Zealand on attempting to crack the protocol of the S2000 scanner. He had the S2000, a Jaycar kit OBD2 scanner, and a sort of "Y" cable to enable the Jaycar scanner to see what packets the S2000 was sending. But that was never completed. If it was, and something home-made could interrogate the stick-pair voltages (the Battery ECU measures the voltage of each pair of sticks, or 12 cells), then the rescue idea might be feasible.

Though now that I post this, it occurs to me that something that connects to the wiring that monitors the cell voltages (perhaps with a different sort of "Y" cable) would be able to monitor the cell voltages. Well, two "Y" cables, since each half-pack would need its own "Y" cable. Maybe it needs a small computer with a USB connection and a 20 to 1 multiplexer to scan the various string-pair voltages... oh. Of course, it would have the usual problem of increasing common mode voltage; parts of the circuit would have up to 360 V difference to other parts. So that would be tricky to wire up. It's all done safely in the battery ECU already... but we can't easily get to it. It's frustrating.

Another thing I learned is that the NHW10 will drive quite happily with the warning triangle, and even turtles coming on and off. Things must be pretty drastic to get the 20 km/h limit.

We also decided to fire up the repairable writeoff car, since it hasn't been used for some time. It would be in a similar state to the cars I'd be trying to rescue. We used the boost charger to get the engine running. We used the scanner to find the weakest stick-pair, pair 9. It would have the lowest voltage during discharge, and the highest voltage when charged. After running a short while, the motor (edit: I means "engine") started running at a higher speed. I had guessed that this indicated the start of an equalisation charge, but not in this case at least. The current went to zero. We found that the "delta SOC" value had gone up to 58% (or perhaps higher), which is apparently alarming enough that the hybrid ECU decided to not continue charging the pack. We repeated this a few times, with the same result.

This made me realise that there are plenty of reasons that the engine will not charge the pack, so any recovery would have to be on the bench. However, the car would presumably still be drivable, so I suppose that's not so bad. It just means that the rescue will almost always result in a drive back to the garage, where either a long slow equalise might fix it, at least temporarily, or bad sticks, or the whole pack, can be replaced. I was hoping that at least some of the rescues would result in a running vehicle the same day, which would make the customer happy, and they'd cheerfully fork over some money for the service. The more expensive options they might have to think about long and hard.

We talked about that aspect over lunch. For example, maybe I can figure out a good way of putting 1.4 NHW20 packs of prismatic cells (which are far more reliable then the D cells in the NHW10s) into a NHW10 box. Would customers be willing to pay around $5000 for a reliable pack that should last the life of the car? Would used car buyers pay around $5000 more for a NHW10 with a reliable pack? Sadly, I can't see it. I think that there will be enough used NHW20s around, some at low prices, that would be more attractive than the older NHW10s. So I think that the business model for the rescue business is flawed.

The idea of converting NHW10s to plug-in or full electric seems flawed for the same reason. It would add more value to the car, but at an even higher cost, and the Prius battery ECU can't be guaranteed not to attempt an "equalise charge" of the pack, which could be disastrous for a lithium pack.

I'll let the ideas rattle around in my head for a little longer, to see what might still work out. I've taken home an empty NHW10 battery box, in case I want to try to fit the NHW20 cells into one. Mr Mik has so many of these (seven) that he'd have to take some to the dump soon anyway.
Last edited by coulomb on Sat, 17 Dec 2011, 15:39, edited 1 time in total.
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antiscab
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Toyota Hybrid first edition what can be done

Post by antiscab » Sat, 17 Dec 2011, 10:12

coulomb wrote: Without this scanner, the only way to get the stick (strings of 6 cells manufactured into a sort of rigid tube) voltages would be with a multimeter on the ends of the sticks. I envisaged this as a fairly simple exercise, but alas, the only practical way is to take the battery box (almost the width of the car and weighing some 60 kg) out of the car, and take out the two half-packs from the removed box. This makes the "instant diagnosis" part of the business plan rather difficult.
The Rennacs scanner in theory can do that, but I have yet to get it working
Its a OBD to USB converter and plugs into any laptop
coulomb wrote: Another thing I learned is that the NHW10 will drive quite happily with the warning triangle, and even turtles coming on and off. Things must be pretty drastic to get the 20 km/h limit.
This is true of my Prius,
however, these are some things that cause the really severe 20kmh limit:
delta SOC above 50%
pack above temp limit (either really hot cell, or hot pack)
voltage of any stick below ~5.5v at low load

coulomb wrote:After running a short while, the motor started running at a higher speed. I had guessed that this indicated the start of an equalisation charge, but not in this case at least. The current went to zero.
That's the sign of the 20kmh limit
The revving engine is to indicate to you, as well as other road users, that you have effectively broken down.
You slow down at 1kmh/sec if you were previously above 20kmh, irrespective of throttle position

The main contactor also opens
coulomb wrote: The idea of converting NHW10s to plug-in or full electric seems flawed for the same reason. It would add more value to the car, but at an even higher cost, and the Prius battery ECU can't be guaranteed not to attempt an "equalise charge" of the pack, which could be disastrous for a lithium pack.


An equlisation has a voltage limit (~370V IIRC?), which is below that of the lithium batteries limit (if using 100 LiFePO4 cells)

If running top balanced, thats not really an issue

you can use the BMS to trigger an over temp alarm (send the PTC sense resistance really high) which would terminate any equalisation anyway

Matt
Matt
2017 Renault zoe - 25'000km
2007 vectrix - 156'000km
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1999 Prius - needs batt
2000 prius - has 200 x headway 38120 cells

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coulomb
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Toyota Hybrid first edition what can be done

Post by coulomb » Sat, 17 Dec 2011, 14:05

antiscab wrote: The Rennacs scanner in theory can do that, but I have yet to get it working.
Its a OBD to USB converter and plugs into any laptop
Oh, yes, Mr Mik mentioned that. He doesn't like the way you have to purchase new software modules (I could live with that I think), and how (for some purposes at least) you have to use their servers to process your data. I think most people would prefer not to rely on the "mother ship's computer".

I haven't looked into the details of that. However, it does seem that the Rennacs can do what I would want. It also means that a DIY solution is possible, perhaps using say the Silcon Chip OBD2 scanner as a guide.

http://www.rennacs.com/
http://www.siliconchip.com.au/cms/A_111859/article.html
coulomb wrote:After running a short while, the motor started running at a higher speed.
That's the sign of the 20kmh limit
Ah. That's definitely worth knowing. It means that taking home the Suzi Auto Prius would either require towing or a lot of patience. It also affects the practicability of moving the other Prius from Bribie Island to somewhere (probably home) where I can work on it.
The revving engine is to indicate to you, as well as other road users, that you have effectively broken down.
Heh. I would have preferred flashing blinkers, like hazard lights. Mr Mik and I were wondering why the engine revved like that.
The main contactor also opens
Really? I wonder how the power gets through to the diff/wheels then. Maybe it relies on the drag and/or cogging torque of MG1. With MG1 at 0 RPM, it would seem the car could do from 40 km/h upwards.... maybe with MG1 spinning a little that would come down to about 20 km/h.

Or maybe the hybrid ECU can maintain MG1 spinning as a generator, providing a little power for MG2, without the pack being connected. That seems more likely. Ah, that might be another reason for keeping the ICE at a higher (~ 2500 RPM) speed - that might be the speed at which MG1 generates about 330 V to mimic the presence of the pack. At 1800-2500 RPM and low speeds, MG1 would be near its maximum speed. I would think that MG2 could run the car at higher speeds than 20 km/h without the pack connected, though.
An equalisation has a voltage limit (~370V IIRC?), which is below that of the lithium batteries limit (if using 100 LiFePO4 cells)
Yes, I was thinking CALB cells, with their 3.60 VPC limit. You could just use TS/Winston/Sinopoly which would handle ~ 3.7 VPC without a problem.
you can use the BMS to trigger an over temp alarm (send the PTC sense resistance really high) which would terminate any equalisation anyway
Heh, good idea.
Nissan Leaf 2012 with new battery May 2019.
5650 W solar, 2xPIP-4048MS inverters, 16 kWh battery.
1.4 kW solar with 1.2 kW Latronics inverter and FIT.
160 W solar, 2.5 kWh 24 V battery for lights.
Patching PIP-4048/5048 inverter-chargers.

Mr. Mik
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Toyota Hybrid first edition what can be done

Post by Mr. Mik » Sat, 17 Dec 2011, 14:41

I haven't looked into the details of that. However, it does seem that the Rennacs can do what I would want. It also means that a DIY solution is possible, perhaps using say the Silcon Chip OBD2 scanner as a guide.

http://www.rennacs.com/
http://www.siliconchip.com.au/cms/A_111859/article.html
I have built this silicon chip scanner before I got the S2000. As expected, it does not work with the NHW10. However, it might be possible to use it to "snoop" the data stream of the S2000.
After running a short while, the motor started running at a higher speed.
The main contactor also opens
Later on I looked up the error codes that the S2000 was showing. The relevant one here was: "C2573 - High Voltage System Failure. Requests to turn the System Main Relay OFF to the hybrid ECU."

Mik
There is always a way if there is no other way!

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