NiMH vs Li-Ion battery - what's the deal?

Thanks - I did wonder. I'm still to decide what I'm buying - there are almost no Gen 4 Prius around here, and I haven't managed a drive in one yet. But some dealers have Gen 3 and Gen 3s with Solar Roof (and with nearly everything available on Gen 3 except a spare wheel) at discounted prices - which is tempting too.

 

remains consistently morose throughout...
the Prius geeks' wishes here may play almost no part in Toyota's marketing decisions

 

It also handles better without all that unnecessary weight perched on top.

 

Very pleased with the 2016 and no sunroof! Do not miss it at all.

 

I thought lion batteries didn't like being fully discharged around 100 or so discharges and they are kaput?

LG-H901 ?

 

No, not unless you are talking about 'dumb' Li-ion that have no SOC or temperature management (such as laptop batteries).

Automotive batteries don't allow a full charge or discharge, and most have active temperature management. Those that don't use a passive temperature management system.
Afaik, all control the rate of charge/discharge as well.

Automotive Li batteries have an 8 year warranty, some even for unlimited miles.
Many Volts report no noticeable battery degradation after 5 years.
Tesla expects it to be 12-15 years before their packs degrade to 70% original capacity.

These are not your average laptop battery

 

Thanks for your kind explanation, appreciate it.

LG-H901 ?

 

I wonder if it would be possible to modify a 2nd or 3rd gen Prius to accept the new 4th gen NiMh or Li-Ion batteries without too much work. I figure that the answer is probably no.

 

That's probably going to be a popular question.
The first question is battery cost, and we don't have the numbers yet for the new batts.

 

Physical dimensions are different. OBDII commands that could query the battery and fans no longer work on the gen 4, so the software in the batteries must be different, and if that is different, it must require that the other software in the rest of the car be different to match.

Maybe on a cell by cell basis, but I would check the dimensions first. Also a differing battery chemistry would require a different charge / discharge usage, probably controlled by the software also.

 

i read the whole thread and this makes the most sense. besides, it helps with marketing in case someone wants to argue Ni-MH is "old" technology. C'man, the whole concept of a car is old technology alright.

 

In the USA our national characteristic is we support new technology sometimes snake oil to a fault. So we are very much of the mind, out with the old, in with the new.

 

I think we at the tipping point where Li-ion batteries become cheaper than NiMH for cars. Lithium is a more plentiful element than nickel, making it cheaper to start with, and the investment into improving Li-ion chemistries and manufacturing is starting to pay off. NiMH was less costly to begin with because it didn't need built in circuitry for battery safety.

Toyota likely pays the least for NiMH, but they made a large investment into the entire supply chain for their packs. BASF has claimed some preliminary testing shows that NiMH might be improved upon, but there will always be the supply of nickel to consider.

 

Are you sure you want to say that? we might hear Toyota prices soon for Gen4 replacement batts, but I am thinking @Grus said Prius v EU Li was 3x higher than NiMH.

 

The $4.1k Li-ion pack vs $1.6k NiMH pack was a story rooted several years ago.
Since the new Gen 4 Li-ion pack is 25% smaller in nominal capacity,
the technology and production scale evolve fast,
and the price premium of Li-ion cell over NiMH cell will become smaller after being assembled to a final pack,
I guess the new Gen 4 Li-ion pack will be much less expensive than 3x NiMH ones.

 

OK I guess we should see Toyota part number costs at some point?

 

The price they quote for replacement doesn't necessarily reflect the cost in manufacturing the car. Toyota has claimed the lithium pack in the PiP cost $1200/kWh, while Nissan is charging $5000 to replace the pack in a Leaf. To be clear, I'm talking about costs on the per cell basis, assembling them into a pack will add cost to the part.

With the Gigafactory, Tesla aims to get their cost below $200/kWh. With concessions to LG, GM is paying near $100/kWh for the Bolt's battery. The cost for the batteries was most likely in the $600 to $900 per kWh range just five years ago. During the same time NiMH has been around $500/kWh. As I said Toyota is likely paying less, because of their investment, and perhaps we'll see some decreases since the large format patent is expired, but I don't see a reason for a decrease in cost at the same rate as in Li-ion.

 

now, i think there is more to that.
looks like toyota is using Li batteries to manipulate car weight class for optimizing EPA MPG claims. probably similar in japan. clues are here: Prius FE Answers buried in the EPA Test Car Database | PriusChat

 

...well I wouldn't bet against that either...I see other games going on so I can certainly see that