Project Lithium Nexcell V2

Right! (Is the car 'certified' for it stock pack? Where can I find this certificate?)
You have DC power charging and discharging the pack as a whole. Voltage and current is controlled.
The rest of the system doesn't care what flavor the chemistry is of the individual cells.
Of course the replacement cells have to handle the rated current that the Ni-Mh cells handled.

My main concern would be the lack of Thermal Management for the Li-ion pack.
What happens when my Gen 3, and this new Li-ion pack is at -5° F some mornings?
Maybe this mod should have temp limits and if your location is out of limits, No Nexcell for you....

 

What properties do you suppose have been programmed in for doing that control of voltage and current you just mentioned?

 

A current limit, different for each direction? This could easily be recorded with a clamp on ammeter, correct?

And those current limits changing with voltage to a degree - - less charge as the pack gets full - more discharge with a full pack, and then the opposite with a low pack...
I assume....

Isn't that how the standard hybrid system works, regardless of cell chemistry?
The Prius has versions with a Li-Ion pack and the old Ni-Mh pack, correct?

I'm not concerned about this current/voltage question with this replacement Li-Ion pack.
I'm concerned with using it in the extremes of temps in my location.

Only I'm not too concerned because my pack seems fine at 13 years and 128k miles.
Maybe someday in the future there will be more info on this pack.

Do you think the big cylindrical Ni-Mh cells make more sense at this time if upgrading?
Or just go to the dealer and buy what they're selling?

 

Or queried with a scan tool, as charge current limit, and discharge current limit (though they're actually shown in watts, power units). The ECU does adjust those, based on its assessment of the condition and temperature of the battery; I think they are 33 kW and 27 kW or so, when it hasn't assessed any need to reduce them.

Of course, those aren't the only parameters that matter. You only rarely see the system using currents that high, and only for moments at a time when you do. Most of the rest of the time, the system is choosing to charge or discharge at much more moderate levels. And it is also making all of those choices informed by its assessment of what is good for the battery in its current conditions.

You seem to be thinking the programming to make those assessments hasn't incorporated any knowledge of how a specific battery type works.

I believe Gen 4 does. I don't remember a Li-ion flavor for Gen 3, but I'm not sure.

It might be interesting to compare two trims, one with each battery flavor, and see if they use the same firmware calibration ID in the power management control ECU.

 

Jack has done severe weather testing hot and cold years before he released this technology to the public. It's also publicly available info (if you looked).

 

I think I did look, a while back. There was quite a bit of stuff posted, but didn't seem to have attracted much peer review.

I could build a thing myself and think of a lot of tests to do on it, and publish those, and you might still feel (if you weren't an expert yourself in the subject matter) that you would like to see an expert who wasn't me evaluate how well-designed and soundly-conducted my tests were. I wouldn't be offended if you felt that way. That might be the way some people still feel about Jack's project, and I wouldn't expect him to be offended by that.

 

Jack bought off the shelf cells, correct? Those should have a spec sheet on what the temp limits are and how they should be treated in extreme temps.
Jack doing his own testing is not the same thing.

 

I would look at the spec sheet. You guys are talking about the discharge temps. The typically max freezing temp the battery can withstand without damage in lithium is -30c(-22F) to -20c(-4F) depending on manufacturer and age of tech, but thats about the lowest. Now the older stuff we are probably using is probably rated to -4F. Now for charging temps.
Charging temps for nimh and lithium typically start to be reduced by a spec at either 41F or 32F. Nimh typically reduces to very little charging current allowed down to around 0F. Lithium ions typically are not permitted to be charged below 32F without battery damage occuring. Notice it will charge, but battery damage will occur (lithium dendrites will form). So typically manufacturers will include charging at temp limits especially for the low temps and either allow the battery to discharge to warm itself up or even have installed battery warmers to help out further.
This is more or less why typically certain battery options on the gen 4 priuses aren't always available in certain northern climate areas. Too cold and they don't deem it to be a beneficial option to be sold there.
This is also the reason why Tesla has their heated and cooled batteries and why you hear stories of batteries taking 45 minutes of sitting on the charger up north before they actually allow charging to start.

 

1. That's my point with this after market Li-ion replacement pack. Without a Thermal Management System Li-ion isn't a good option.
2. It's not just Tesla. Most EV's have a TMS for the pack to warm and cool it as required. (Nissan was the exception for years)
It takes a particular set of conditions to get an unplugged EV 'too cold to charge'. Most use pack power to power the TMS down to a certain SOC. Most EV owners know to keep it plugged in at temp extremes just for the TMS.

And this is why I'll wait and see regarding this after market option for a replacement pack. And also, my stock pack is doing fine.

 

Yup. Thats kinda why the OG Leaf's sucked so bad. Tesla is just a good example of heating and cooling the battery and its benefits and longevity.

 

I’ve been patiently waiting for this to come back in stock. Just a little while ago I got an in stock notification. I added it to the cart and went to check out and I get a message saying they are out of stock.
Ahhhhh!
Those went fast.

 

Are you talking about the V2 upgrade kit for $80 or the actual lithium cells kit? I have been checking daily for weeks now and patiently waiting like you, for the lithium cells. Please tell me the actual shipment of cells isn't sold out already

 

Sorry to tell you this was the full $2k V2 pack. He had a small order come in and it was immediately sold I was messing around at checkout trying to decide if I wanted to have it shipped or go pick it up. That small delay cost me the order.
Another shipment should be in next month.

 

Do they charge for shipping?

 

Oh okay, but the main shipment hasn't been made available for order yet? The ones arriving early June. I was told they'd be available to order 2 weeks before they arrive.

 

Yes.

That was not the main order.

 

(Regarding charging for shipping).

Their prior address was practically down the street from me, maybe 1 mi away maximum.

Confirming the pickup address before you decide is probably ideal…

 

Preorders are available since early this morning

 

Yes, it's a little over $100 via UPS... But you're less than 1/2 hour drive from where it's shipping from in La Verne, CA. so if you email: <[email protected]> he'll set you up with a pickup and save you that money. And if you use my affiliate link to purchase: https://projectlithium.com/?ref=9qLPw I'll not only get that taken care of for you, but can offer unlimited tech support and help you find an installer, or coach you through the process if you or a friend or family member want to save the $450-ish charge for install. It's very easy work that takes an afternoon of your time.