KiwiEVs next project fast EV
- Thread starter kiwiev
- Start date
oatnet
1 MW
Cowardlyduck said:
Ah you are right - I am too focused on my own design criteria, and not yours.
I'm not worried about range, so I think about having the lightest battery that can deliver as many Amps as the motor can handle, which a set of 28s and 7s modules could deliver for less than $2,000 and 65kg. However, it looks like Conrad wants more range, and this build weighs more so it will consume more WHM anyhow, so capacity becomes a priority. The NMC pouches would be lighter than a123 anyhow, and with more AH for range c-rating ceases to be an issue. Besides I don't think Okashira has enough modules for s pack that size.From a cost standpoint, you'd have to consider cycles - not sure which 18650s you are looking at, but if they deliver 500 cycles, and something else delivers 2,000 cycles, then in theory you need to replace the pack 4 times to have the same lifespan. OTOH, by the time the first 18650 pack is done, something newer/lighter/cheaper will be available.
A problem with 18650 is the number of cells in parallel - it just takes (1) bad cell to drain and fail the whole parallel string. The more cells in parallel, the more chances of having a failed cell, or bad connection to the cell.
A problem with the pouches is joining them together is a challenge. I've done manual crimps of a123 pouches that I would trust for 150a or so, but not 500a. OTOH, the crimp-on connectors that Dr Bass posted here https://endless-sphere.com/forums/viewtopic.php?f=9&t=75710&start=25#p1164473 could make that a whole lot easier, and the scale of this pack would make it worth buying the expensive crimping tool. I'd wonder whether the pouches need compression, and conformal layers between the cells, cooling, edge protection, etc.
Each solution has its trade-offs. :lol:
-JD
kiwiev
100 kW
I think that is why Tesla fuse each and every cell then each module is fused.
I agree about the cycles.
CD is there strips that we can use with the spot welder that could act as a fuse
Cheers Kiwi
I agree about the cycles.
CD is there strips that we can use with the spot welder that could act as a fuse
Cheers Kiwi
Yeah, fusing each and every cell sounds nice, and it does have it's benefits, but I'm not 100% convinced it is worth it TBH.
Consider the scenario it prevents....a single cell suddenly draining the rest of the parallel bank. For this to occur it either has to reverse polarity, or dead short internally, both of which are extremely unlikely scenario's with today's cells.
On the other hand, if the cell is defective and drains slowly (more likely), it will still drain the rest of the parallel bank regardless of a fuse being there or not.
A fuse will also restrict the amount of current that can be safely delivered without them blowing.
The guy that made that Electric VW van tested this with the Tesla modules he re-purposed and from memory I think he found he could safely draw up to 50% more current over the fuse rating without them blowing, so the current limit isn't that much of a concern.
The main thing to consider is the amount of effort required vs the risk of it happening. If I was making the pack, I would make an extra 1 or 2 parallel banks when building it, so I could swap them in/out if it turned out there was a dodgy cell effecting one bank. That then allows quick repair, and gives you the time to pinpoint exactly which cell is causing you problems, assuming you catch it before it destroys that bank.
I'm not aware of any off the shelf components that can be used to fuse packs on an individual cell basis. On the other hand, if you are already dividing your parallel strings into groups of 25, you could easily fuse each of those groups, then at least you wouldn't loose more than 25 cells at a time. You could then just make an extra few 25 cell groups when making the pack to keep as spares. Just an idea.
Cheers
Consider the scenario it prevents....a single cell suddenly draining the rest of the parallel bank. For this to occur it either has to reverse polarity, or dead short internally, both of which are extremely unlikely scenario's with today's cells.
On the other hand, if the cell is defective and drains slowly (more likely), it will still drain the rest of the parallel bank regardless of a fuse being there or not.
A fuse will also restrict the amount of current that can be safely delivered without them blowing.
The guy that made that Electric VW van tested this with the Tesla modules he re-purposed and from memory I think he found he could safely draw up to 50% more current over the fuse rating without them blowing, so the current limit isn't that much of a concern.
The main thing to consider is the amount of effort required vs the risk of it happening. If I was making the pack, I would make an extra 1 or 2 parallel banks when building it, so I could swap them in/out if it turned out there was a dodgy cell effecting one bank. That then allows quick repair, and gives you the time to pinpoint exactly which cell is causing you problems, assuming you catch it before it destroys that bank.
I'm not aware of any off the shelf components that can be used to fuse packs on an individual cell basis. On the other hand, if you are already dividing your parallel strings into groups of 25, you could easily fuse each of those groups, then at least you wouldn't loose more than 25 cells at a time. You could then just make an extra few 25 cell groups when making the pack to keep as spares. Just an idea.
Cheers
Here you go...
This says it all...to some degree lithium cells are self balancing:
[youtube]735Rb9TpVsY[/youtube]
I would check a bit more often than once every few years, though it does prove the point...unless you have a completely dodgy cell, you pretty set.
Cheers
This says it all...to some degree lithium cells are self balancing:
[youtube]735Rb9TpVsY[/youtube]
I would check a bit more often than once every few years, though it does prove the point...unless you have a completely dodgy cell, you pretty set.
Cheers
oatnet
1 MW
There are a wide range of lithium chemistries and quality of of manufacturing, each variation with its own unique properties; some are relatively self balancing like the Koni (spinel LIMn), whereas others - like Headways (LiFePO4) and Hobby King (LiCo) - certainly are not.
Funny to see that other guy's VW Bus conversion, he did a nice job. In 2008 I built the first ever VW Van conversion (we'd call it a VW Bus here) that used lithium cells - first Headways, then PSI, then a123. It was crude (before I'd learned machining and welding and VW mechanics) and always held back by a crappy Kelly Controller but I learned a lot along the way. I wish I had sunk $$$ into a Zilla controller back then because I would have gotten a lot more enjoyment from it, part of why I now push people to use better controllers. Here is the build thread for it:
https://endless-sphere.com/forums/viewtopic.php?f=34&t=8012
Good point about the single-cell fusing - if you buy fused cells, that will mitigate that risk. I've seen 18650 cells with built-in fusing on more volitile lico chemistries.
Funny to see that other guy's VW Bus conversion, he did a nice job. In 2008 I built the first ever VW Van conversion (we'd call it a VW Bus here) that used lithium cells - first Headways, then PSI, then a123. It was crude (before I'd learned machining and welding and VW mechanics) and always held back by a crappy Kelly Controller but I learned a lot along the way. I wish I had sunk $$$ into a Zilla controller back then because I would have gotten a lot more enjoyment from it, part of why I now push people to use better controllers. Here is the build thread for it:
https://endless-sphere.com/forums/viewtopic.php?f=34&t=8012
Good point about the single-cell fusing - if you buy fused cells, that will mitigate that risk. I've seen 18650 cells with built-in fusing on more volitile lico chemistries.
Oatnet, I just read your VW thread for the first time, and (re)read your dune buggy thread. Huge respect for all the work you put into those (and your Vectrix). It seems you've been down the road of fused cell blocks before. What are your thoughts on doing it that way?
As for HK (LiCo) not self balancing, this is contrary to my experience. I've been running some Zippy Compact cells for over 2 years now and have close to 300 (charge) cycles on them. The outside cells have all puffed slightly and now discharge slightly faster than the rest, however when I throw them on the bulk charger it brings them all back up to within 15mv of each other every time.
I typically balance charge once every 2-3 weeks, but really don't even need to. This is why I say they are 'self balancing'.
Sure, leave them on the shelf long enough, or discharge them deeply enough and the balance could go way out of whack, but under non-abusive usage patterns they will typically self balance IMO.
The 18650 cells we are looking at/talking about using are the newer 3500mha cells from Panasonic (Sanyo) (NCR18650GA, LG (INR18650-MJ1), and Samsung (INR18650-35E).
I don't know heaps about the chemistries, but from what I read both NCR and INR chemistries are significantly safer than the pure cobalt/manganese 18650's used in the past 5-10 years. So far I'm yet to hear/read of a single fire with any of these newer 3500mah cells, and I did read somewhere that they are dead-short tested without any catastrophic failure of the cell structure.
This is why I'm super exited to get these cells and put them to use. Lessons learned from the past on batteries are definitely good to heed, however when the battery tech keeps evolving and changing like it does, those 'lessons' need to be carefully analysed to see if they are still relevant/applicable.
Cheers
As for HK (LiCo) not self balancing, this is contrary to my experience. I've been running some Zippy Compact cells for over 2 years now and have close to 300 (charge) cycles on them. The outside cells have all puffed slightly and now discharge slightly faster than the rest, however when I throw them on the bulk charger it brings them all back up to within 15mv of each other every time.
I typically balance charge once every 2-3 weeks, but really don't even need to. This is why I say they are 'self balancing'.
Sure, leave them on the shelf long enough, or discharge them deeply enough and the balance could go way out of whack, but under non-abusive usage patterns they will typically self balance IMO.
The 18650 cells we are looking at/talking about using are the newer 3500mha cells from Panasonic (Sanyo) (NCR18650GA, LG (INR18650-MJ1), and Samsung (INR18650-35E).
I don't know heaps about the chemistries, but from what I read both NCR and INR chemistries are significantly safer than the pure cobalt/manganese 18650's used in the past 5-10 years. So far I'm yet to hear/read of a single fire with any of these newer 3500mah cells, and I did read somewhere that they are dead-short tested without any catastrophic failure of the cell structure.
This is why I'm super exited to get these cells and put them to use. Lessons learned from the past on batteries are definitely good to heed, however when the battery tech keeps evolving and changing like it does, those 'lessons' need to be carefully analysed to see if they are still relevant/applicable.
Cheers
kiwiev
100 kW
Cowardlyduck said:Here you go...
This says it all...to some degree lithium cells are self balancing:
I would check a bit more often than once every few years, though it does prove the point...unless you have a completely dodgy cell, you pretty set.
Cheers
Yes CD that has been my experience too
I have 3 banks 48 volt cells on my stand alone solar and all cells are with in 0.1 volt
Cheers Kiwi
The Toecutter
100 kW
- Joined
- Feb 8, 2015
- Messages
- 1,313
One of the reasons I had chosen the CALB CAs for my GT6 was their apparent lack of self discharge and their remarkable stability. You can let them sit for months and they will still read within 0.001V when compared to each other and when compared to the previous readings. There virtually is no self discharge or tendency to get out of balance.
They don't seem to need a BMS based on the various blogs/videos/demonstrations I have seen, but I have yet to try a full cycle on them yet. They do need periodic bottom balancing, however, about once every 5 years or so.
Price per kWh is about $400, and according to EVTV's tests, they can reliably peak at 10C for 30 seconds, and do 3C all day long with repeated cycles. I've driven Jack's replica Porsche 550 Spyder conversion with the inferior SE cells, and they very adequately powered a single AC50 motor at ~110V/500A. His pack was 115.2V/180AH. He told me in person that the Spyder does 0-60 mph in 8.5 seconds. I got to floor it, and while I didn't time it, the acceleration was acceptable. It felt like a car that did 0-60 mph in 12-13 seconds, but I suppose the steady/smooth torque of the AC drive masks the sensations associated with hard accelerations, unlike a more torquey DC motor that instead exaggerates them. It was a surprisingly smooth feeling for such a small and quick car. It was still a fast enough car that I could very confidently drive it in all conceivable traffic conditions, a very practical requirement for a road-going vehicle, and as a bonus, it was still fast enough that if I wanted to, I could drive it recklessly and have fun doing it. The folks at EVTV did let me take it to 80 mph, and looking at the speedometer needle rising, its acceleration from 50-80 mph seemed very competitive to ICE cars I've driven that the magazines claim do 0-60 mph in 7-8 seconds, and even though the electric Spyder didn't feel very ballsy at all, the scenery started to seem like a blur as if I were driving something much faster... The efficiency was good, about 180 Wh/mile. The low CdA and mass certainly helped it a lot.
The CA cells are much more power-dense compared to the SE cells. They will run your truck very nicely.
In the U.S. at least, the CALB CA180FI batteries can be readily purchased at $232 USD a piece. The 7.5 lb CA100FI cells are now $125 USD a piece. I do not know what sort of availability they have where you are at.
But here's a few ideas:
===============
Setup #1:
$7,000 USD of them will get you a 96V/180AH pack, and with a modest 6C discharge limit, about 85 KW of peak power from the batteries, going into your torquey twin HPEVS AC35 650A setup. The pack will weigh 370 lbs, and to 80% DoD, give you 13.8 kWh. Easily a 70-80 km range if you do some modest aeromods.
You'll get about 240 lb-ft all the way up to 2,000 rpm or so reaching peak at ~95 horsepower, and keep that peak power all the way to 4,500 rpm.
If you delete the transmission and go direct-drive, you're 0-50 kph time is going to be quick, probably on par with gasoline powered cars that do 0-100 kph in 6 seconds, but your 50-100 kph time will be like a more mundane entry level 4 cylinder car. The vehicle will excel as a truck, however, given that it's torque is available at the low end of its operating range.
I'd estimate 0-100 kmh in under 9 seconds under that setup, 0-50 kmh in 2-2.5 seconds, 400m drag race in the upper 16s, and a top end of perhaps 180 kmh(faster if you build the truck into a full-on streamliner).
And you won't need a BMS, just a suitable charger and all of the bolts/washers/connectors. They can apparently handle 2C charge rates, too.
Setup #2:
You could bump that power up and run two parallel strings of 30 CALB CA100FI cells at 8C instead, for a total of 96V/200AH, 400 lbs weight, 15.4 kWh to 80% DoD, and get 240 lb-ft up to 2,800 rpm, getting you about 125 peak horsepower from the motors. You'd have a 90 km range, too. This pack would cost $7,500USD. This is the lightest setup you will get using CALB CAs where you maximize your inverters' capabilities, and any further weight will reduce your acceleration rate.
You'd probably be looking at a 0-50 kmh acceleration of 2-2.5 seconds, and 0-100 kmh acceleration of under 8 seconds and a 400m time in the upper 15s.
Setup #3:
Run 3 strings of 30 CA100FI cells at about $11k USD. You'll add another 220 lbs or so in batteries for a total pack weight of 675 lbs, and get a 130 km range, but it will be a tiny bit slower due to the added weight. 0-100 kmh just over 8 seconds, 400m drag somewhere in the low 16s.
Setup #4:
Run 2 strings of 30 CA180FIs, costing you $14,000 USD, and get 160 km range.
===============
Your planned setup to use a bunch of smaller more dense cells can only get faster acceleration and better range from there, as the ones described above in this post is a lot more modest in capability than what you're thinking about.
Putting a bunch of smaller cells together is a lot of work for this vehicle. I personally wouldn't want to deal with all of the things that can go wrong when you do this, so best of luck to you! Even as an engineer, I'm much more confident in my capability of building a small e-bike pack out of small cells, than a monstrosity big enough to power a car, and I'd rather not deal with the things that can go wrong doing this in an ebike. The amount of money that could be lost during a battery pack malfunction for a pack big enough to move a car an appreciable distance would make me financially squeamish, but an ebike pack is a much smaller hit to the wallet if it self destructs.
They don't seem to need a BMS based on the various blogs/videos/demonstrations I have seen, but I have yet to try a full cycle on them yet. They do need periodic bottom balancing, however, about once every 5 years or so.
Price per kWh is about $400, and according to EVTV's tests, they can reliably peak at 10C for 30 seconds, and do 3C all day long with repeated cycles. I've driven Jack's replica Porsche 550 Spyder conversion with the inferior SE cells, and they very adequately powered a single AC50 motor at ~110V/500A. His pack was 115.2V/180AH. He told me in person that the Spyder does 0-60 mph in 8.5 seconds. I got to floor it, and while I didn't time it, the acceleration was acceptable. It felt like a car that did 0-60 mph in 12-13 seconds, but I suppose the steady/smooth torque of the AC drive masks the sensations associated with hard accelerations, unlike a more torquey DC motor that instead exaggerates them. It was a surprisingly smooth feeling for such a small and quick car. It was still a fast enough car that I could very confidently drive it in all conceivable traffic conditions, a very practical requirement for a road-going vehicle, and as a bonus, it was still fast enough that if I wanted to, I could drive it recklessly and have fun doing it. The folks at EVTV did let me take it to 80 mph, and looking at the speedometer needle rising, its acceleration from 50-80 mph seemed very competitive to ICE cars I've driven that the magazines claim do 0-60 mph in 7-8 seconds, and even though the electric Spyder didn't feel very ballsy at all, the scenery started to seem like a blur as if I were driving something much faster... The efficiency was good, about 180 Wh/mile. The low CdA and mass certainly helped it a lot.
The CA cells are much more power-dense compared to the SE cells. They will run your truck very nicely.
In the U.S. at least, the CALB CA180FI batteries can be readily purchased at $232 USD a piece. The 7.5 lb CA100FI cells are now $125 USD a piece. I do not know what sort of availability they have where you are at.
But here's a few ideas:
===============
Setup #1:
$7,000 USD of them will get you a 96V/180AH pack, and with a modest 6C discharge limit, about 85 KW of peak power from the batteries, going into your torquey twin HPEVS AC35 650A setup. The pack will weigh 370 lbs, and to 80% DoD, give you 13.8 kWh. Easily a 70-80 km range if you do some modest aeromods.
You'll get about 240 lb-ft all the way up to 2,000 rpm or so reaching peak at ~95 horsepower, and keep that peak power all the way to 4,500 rpm.
If you delete the transmission and go direct-drive, you're 0-50 kph time is going to be quick, probably on par with gasoline powered cars that do 0-100 kph in 6 seconds, but your 50-100 kph time will be like a more mundane entry level 4 cylinder car. The vehicle will excel as a truck, however, given that it's torque is available at the low end of its operating range.
I'd estimate 0-100 kmh in under 9 seconds under that setup, 0-50 kmh in 2-2.5 seconds, 400m drag race in the upper 16s, and a top end of perhaps 180 kmh(faster if you build the truck into a full-on streamliner).
And you won't need a BMS, just a suitable charger and all of the bolts/washers/connectors. They can apparently handle 2C charge rates, too.
Setup #2:
You could bump that power up and run two parallel strings of 30 CALB CA100FI cells at 8C instead, for a total of 96V/200AH, 400 lbs weight, 15.4 kWh to 80% DoD, and get 240 lb-ft up to 2,800 rpm, getting you about 125 peak horsepower from the motors. You'd have a 90 km range, too. This pack would cost $7,500USD. This is the lightest setup you will get using CALB CAs where you maximize your inverters' capabilities, and any further weight will reduce your acceleration rate.
You'd probably be looking at a 0-50 kmh acceleration of 2-2.5 seconds, and 0-100 kmh acceleration of under 8 seconds and a 400m time in the upper 15s.
Setup #3:
Run 3 strings of 30 CA100FI cells at about $11k USD. You'll add another 220 lbs or so in batteries for a total pack weight of 675 lbs, and get a 130 km range, but it will be a tiny bit slower due to the added weight. 0-100 kmh just over 8 seconds, 400m drag somewhere in the low 16s.
Setup #4:
Run 2 strings of 30 CA180FIs, costing you $14,000 USD, and get 160 km range.
===============
Your planned setup to use a bunch of smaller more dense cells can only get faster acceleration and better range from there, as the ones described above in this post is a lot more modest in capability than what you're thinking about.
Putting a bunch of smaller cells together is a lot of work for this vehicle. I personally wouldn't want to deal with all of the things that can go wrong when you do this, so best of luck to you! Even as an engineer, I'm much more confident in my capability of building a small e-bike pack out of small cells, than a monstrosity big enough to power a car, and I'd rather not deal with the things that can go wrong doing this in an ebike. The amount of money that could be lost during a battery pack malfunction for a pack big enough to move a car an appreciable distance would make me financially squeamish, but an ebike pack is a much smaller hit to the wallet if it self destructs.
kiwiev
100 kW
These used 18650 modules are comprised of 2600mAh cells arranged in a 22p15s configuration. They are rated at 100 amps, 150 amps peak. They have an integrated liquid cooling/heating system, but they can also be air cooled in light duty cycle applications. They also have an integrated 100 amp fuse, and an ATX20 connector with cell level connectivity for BMS systems and two integrated thermistors. The packs contain 330 cells, and each cell is independently safety fused on both terminals. They have been lightly used, most with less than 5000 miles on them, and are designed for 100,000 miles to 85% capacity. A preferred configuration for a typical AC50 application is 4p2s for a total of 24kWh of energy with a total of 8 modules. These work particularly well in 48 volt marine and cart applications as well. Quantities are extremely limited, pricing specials are temporary.Capacity: 57Ah, 3kWhHeight: 7.25 InchesWidth: 2.875 InchesLength: 39.0 InchesWeight: 42 PoundsBolt Size: M6 Voltage nominal: 3.8V/Cell, 57.0V/ModuleCharge voltage cut-off: 4.2V/Cell, 63.0V/ModuleDischarging cut-off: 3.3V/Cell, 50V/ModuleMaximum Discharging Current (10 sec.):150 AmpsWarranty Period: One year
Awesome post Toecutter
Thank you
I have these in mind to thinking of 14 modules would like your thoughts please
Cheers Kiwi
Awesome post Toecutter
Thank you
I have these in mind to thinking of 14 modules would like your thoughts please
Cheers Kiwi
The Toecutter
100 kW
- Joined
- Feb 8, 2015
- Messages
- 1,313
kiwiev said:
These features cut out much of the work and make the batteries harder to damage. You can't go wrong with that aspect of this.
If I were ordering them, I'd want some data with regard to their current condition. They may still be slightly above nameplate ratings, which would make them a good solid buy, or they could be showing signs of age young in their life... in which case be careful with your purchase.
How big of a pack and under what discharge and typical trip length can this mileage be delivered? Spending $10,000 on a pack that lasts 100,000 miles breaks even at the equivalent of a 30 mpg ICE car running on $3/gallon gasoline. In Australia, gasoline is probably significantly more expensive than it is here though so the economics may still work out in your favor.
Making the truck have a longer range heavily decreases the wear and tear on the cells thanks to shallower cycling for any typical daily usage case. I see potential for certain lithium ion chemistries to last 250,000+ miles, and LiFePO4 even longer still, but you need to use a battery where shelf-life is less of a factor in their demise and size the pack to where virtually no trips drain the battery fully, and 90%+ of trips take it down less than 25% depth of discharge.
I do not know if the battery you are planning to use can be bought new, left unused for 5 years, and still deliver like-new performance as CALBs without a BMS can, even if they may still end up being very adequate for your usage case.
A preferred configuration for a typical AC50 application is 4p2s for a total of 24kWh of energy with a total of 8 modules. These work particularly well in 48 volt marine and cart applications as well. Quantities are extremely limited, pricing specials are temporary.Capacity: 57Ah, 3kWhHeight: 7.25 InchesWidth: 2.875 InchesLength: 39.0 InchesWeight: 42 PoundsBolt Size: M6 Voltage nominal: 3.8V/Cell, 57.0V/ModuleCharge voltage cut-off: 4.2V/Cell, 63.0V/ModuleDischarging cut-off: 3.3V/Cell, 50V/ModuleMaximum Discharging Current (10 sec.):150 AmpsWarranty Period: One year
Awesome post Toecutter
Thank you
I have these in mind to thinking of 14 modules would like your thoughts please
The specific capacity is nice. 23 kWh to 80% DoD in 346 lbs of battery with a 126V/228AH setup would be wonderful. Given the sheer number of cells(15*2*22*4 = 2640 cells!), I'd personally set 100A from each module as a safe limit. This would give you acceleration performance similar to "Setup 1" in my earlier post above. 150A peak, if they can truly and reliably do this, will make this truck very fast.
How much would they cost?
Maxing out twin 96V/650A inverters with the lightest possible battery configuration that can deliver that level of power without damaging itself is how to size it, if you're going to be wanting the best acceleration performance possible with these drive systems.
With 14 modules, you could do 2s7p for 126V/400AH, assuming they all worked. Imagine a 200+ km range...
Don't forget the truck nutz:
http://www.trucknutz.com/
...because at 150A per module string, you're looking at them sagging to perhaps 110V while getting 1,050A draw from them. You're going to have 250 lb-ft up to 2,500 rpm, peak there at about 115 horsepower, and keep that 115 horsepower all the way past 5,000 rpm.
You probably wouldn't need a transmission anymore, as that's just sucking power away from your wheels.
What are your wheel/tire size, gear ratios and rear-end ratios, by chance? Expected drag coefficient and weight? I could input them into the following simulator and see what performance it says you will get:
http://www.nightrider.com/biketech/accel_sim.htm
And using this graph to determine your motor curve:
http://www.hpevs.com/Site/power_gra...ac50 96 650 amp volts imperial peak graph.pdf
kiwiev
100 kW
So these modules are USD $990 each
I like them because as you say they are packaged and work also I can use the heating feature as we have snow down here.
I agree and as they are coming from your side of the planet returns will be awkward :|
Yes :lol: they have these things down here too
Gas down here is around AUD $1.15 per liter
So I am on stand alone solar and having a larger pack as you say less deep dis-chargers, so my daily drive would be 70 Km so if I cant charge some days to full have the extra capacity in the truck would smooth out the high and low solar outputs.
And the ability to not charge when I don't have sun and then charge when I do, I have a 9 Kw solar so I just need to make something to charge the truck when the controller has topped up the solar batteries. (on a good day I can make 38 Kw but it will only make for the load it sees.)
The other bonus is the modules will fit on the tub with a nice alley checka-plate floor
I may get 16 modules to really access the 650 amp controllers this would give me 48 KwH for around 310 Kg so weather or not the extra 38 Kg is worth it ie. range verse performance :?
I like the gearbox as we live in the mountains the Sonic is cool without one but a gearbox is a torque multiplier, The sonic doesn't really punch until 20-30 Kph but like you said in you drive of Jacks Porsche they AC is smooth not eruptive. The sonic at 20-120 Kph you can take your foot off the gas and punch again and it really puts you back in your seat again .
Cheers Kiwi
I like them because as you say they are packaged and work also I can use the heating feature as we have snow down here.
I agree and as they are coming from your side of the planet returns will be awkward :|
Yes :lol: they have these things down here too
Gas down here is around AUD $1.15 per liter
So I am on stand alone solar and having a larger pack as you say less deep dis-chargers
, so my daily drive would be 70 Km so if I cant charge some days to full have the extra capacity in the truck would smooth out the high and low solar outputs.And the ability to not charge when I don't have sun and then charge when I do, I have a 9 Kw solar so I just need to make something to charge the truck when the controller has topped up the solar batteries. (on a good day I can make 38 Kw but it will only make for the load it sees.)
The other bonus is the modules will fit on the tub with a nice alley checka-plate floor
I may get 16 modules to really access the 650 amp controllers this would give me 48 KwH
for around 310 Kg so weather or not the extra 38 Kg is worth it ie. range verse performance :? I like the gearbox as we live in the mountains the Sonic is cool without one but a gearbox is a torque multiplier
, The sonic doesn't really punch until 20-30 Kph but like you said in you drive of Jacks Porsche they AC is smooth not eruptive. The sonic at 20-120 Kph you can take your foot off the gas and punch again and it really puts you back in your seat again .Cheers Kiwi
Attachments
kiwiev
100 kW
The sonic at 20-120 Kph you can take your foot off the gas and punch again and it really puts you back in your seat again .
In the video you can see my head go back we the engineer punches the throttle and we are already doing 130 Kph
Cheers Kiwi
[youtube]ylC5FdssgCo[/youtube]
In the video you can see my head go back we the engineer punches the throttle and we are already doing 130 Kph
Cheers Kiwi
[youtube]ylC5FdssgCo[/youtube]
Hillhater
100 TW
kiwiev said:
I would be very sure to check the manufacturing date of those cells. ,!
I think its been some years since they assembled modules using 2600mAhr cells. :wink:
kiwiev
100 kW
Hillhater said:
Good point Hilly I will find out
Cheers Kiwi
kiwiev
100 kW
galderdi said:
Cudal air strip NSW near Orange the engineer has access and was driving.
Thanks for kind comments, btw are you north or south side of Brisbane?
Cheers Kiwi
kiwiev
100 kW
galderdi said:
There were 3 gps units but data was for the RMS so I cant see it.
Cheers Kiwi
oatnet
1 MW
Cowardlyduck said:
Wow, thanks for the high praise CD!
I've played with a fair amount of stuff but I don't think I've achieved anything as clean as KiwiEVs sonic or Kepler's stealthy road bikes. I have always fused my balance wires, and I try to break my packs into smaller fused segments - I think the vectrix was fused every 10 cells - so in the worst case I'd deal with a 36v fire than a 170v plasma ball. However I have not fused individual paralleled cells like Tesla does, and I think that is what you are asking. I think it is a great idea, but I don't have the skills or patience to do it on thousands of 18650 cells. I have seen 18650 cells that come with fuses installed, but they are on chemistries that are more volatile than I would use. Granted I have a low risk tolerance, and those chemistries would probably fine in a container that isolates them from vibration, crush/penetration, and temperature extremes.
I have been a vocal proponent of LiFePO4 over the years, but now even I have jumped onto the 18650 revolution with the Samsung 30Q's, and see a number of other variants that I'd consider for other applications. The NCR and IMR cells you reference look like good choices, I personally would not be as comfortable with ICR cells - but they are still lithium. My only concern was to painting the characteristics of lithium cells with too broad a brush when you said "to some degree lithium cells are self balancing."
Chemistry: as I understand it, LiMn204 hits a peak voltage and stops taking on more current, giving a self-balancing effect under bulk charging. LiFe and LiCo are lithium, but will keep on taking current and increasing voltage until you have an event.
Quality: A-grade major manufacturer 18650's could have the quality control yielding flawless jelly rolls and matching IR to the 6th decimal point; counterfeit cells and the c-grade rejects that often find their way onto the market, likely do not and are more likely to drift. My a123's have had close IR and held balance well, my Headways and a dozens of other types of LiFe I have played with did not. Budget Ping packs met a need but drifted like crazy and frequently lost paralleled groups. It sounds like you have had decent luck with your HK packs, I've read many accounts of packs delivered with a substandard cell(s) and people struggling to keep them balanced.
Assembly: Cells may have identical IR at the same temperature, but will have different IR at different temps; the groups of paralleled cells in the middle of the pack will be hotter than the ones at the end of the pack. I have seen LOTs of BMS that mismanage a cell and cause drift, packs built with series cells whose heatshrink was touching and wore enough for microvoltages and worse. The differences that are subtle in a 5p configuration could be magnified when scaled up to 100p.
-JD
Lurkin
100 kW
Wait a second. If I get a shirt with "engineer" on it can I drive?!?! 8)
Where are we at with the shagon wagon?
Where are we at with the shagon wagon?
kiwiev
100 kW
Lurkin said:
Of course you can :lol:
I am catching up with a suplier next week he can get a AC 250hp 237 ft lb motor at 56 kg.
Just checking this out.
I also was thinking of making a solar panel rear tub lid measures 1500mm x 1900mm do you think its worth it?
I could get 5 pannels at 24 volt 5 amp, has anyone plug these straight to a battery with out regulator?
Cheers Kiwi
ridethelightning
1 MW
- Joined
- Jul 21, 2013
- Messages
- 2,010
just found this thread. awesome!
+1 for the honda s2000, its so cute....and thats coming from someone who usually just views cars as something that gets in the way
+1 for the honda s2000, its so cute....and thats coming from someone who usually just views cars as something that gets in the way