battery interchangeable?

wow, i'd be done with that evil co.

 

I'm running out of companies that I am willing to deal with.

JeffD

 

sad, and getting sadder the next 4 years.

 

If you went back to the '60s when I started fiddling with cars, it was "possible" to put just about any engine+box in your car (I didn't, but witnessed a few). Diffs, wheels, carb jets etc were swapped. A/Cs (remember, they sat under the dash?) and Turbos were added. If you didn't have the part, you (or your welding shop) made up the mounting kit. Things like sets of points/plugs, distributors, carburetors were shared between brands of cars.

Not any longer (unless you're BillTheEngineer!!).

 

when i was a lad, we walked both ways to school, uphill.

 

... or did it just feel that way? Me too - this was post-school I was talking about. Teenagedom.

 

feels that way more than ever. it's just not school anymore.

 

Possible, but I suspect you have increased the cost for the pack.
Mainly, having similar voltage outputs isn't enough. A basic lead acid battery charger can damage an AGM type battery, because it requires slightly different voltages during charging. There are far more differences between NiMH and Li-ion than in the variations of lead-acid. While I'm sure Toyota used hardware that can handle both battery types for charging duties, cars are not simply plug n' play like computer components.

Still possible. Some have put a VW TDI into their Tacoma. It just now requires the knowledge of the control software. Simply upgrading the intake or exhaust requires tuning the ECM to actually get a performance change in a modern car; even with manufacturer parts.

That increases the difficulty and cost in making such changes to a modern car, but there is a flip side to this. It is possible to change a car's performance, including improving fuel economy, simple by making changes to the software tune.

 

Open source software would provide more flexibility with a mountain of possible issues, some deadly.

 

The solution is actually simpler and does not incur added costs.

The State-Of-Charge (SOC) of the overall pack is communicated to the "Inverter" which by varying it's output voltage level determines the amount of current that is drawn from or sent to the HV battery depending on the needs of the vehicle and SOC of the battery. As long as both battery implementations have about the same voltage range and current handling capacities, they are then functionally interchangeable. Of course the reported SOC to the inverter would need to be normalized to account for the usable SOC range of each battery chemistry.

JeffD

 

Which is likely in all the Prii ECU coding, but requires to be unlocked from outside.

So swapping the NiMH and Li-ion packs on a Prius should be possible. The mounting hardware, and wire harness should be the same. Tuning the software will most likely need to be done in order for the ECU to know that the chemistry has been changed. From what I've seen for tune prices, that will likely cost $150 to $300 if you need to have someone else to do it. In the future, when a pack needs to be replaced, that might be worth upgrading to a Li-ion pack if the the cost vs NiMH has dropped enough.

Getting an improved Li-ion, or even NiMH, chemistry pack likely isn't going to happen. Toyota wants you to buy a new car for it, so the gen5's pack likely won't be able to back-talk to a gen4 ECU. Most people will opt to pay less for the OEM chemistry when pack replacement is needed for an older Prius. So a third party pack isn't likely to appear, and then those that happen to do so might be like 3rd party batteries for Panasonic cameras, and simply not work because of the proprietary nature of the control software.

 

if you're leaving the main road, you had better be prepared with emergency supplies.

 

In all honesty folks, I would not be surprised if putting the Lithium Ion pack is a drop in install. The whole "ecu tuning" and whatnot is stupid and irrelevant. The voltages don't matter, nothing matters because they wouldn't design the prius with that significant of a difference between a single trim of vehicle and all the other vehicles they make. If you understand how battery packs work, it's like the difference with laptop computers (20 years ago) accepting a Lithium Ion battery or NIMH battery. The car/computer is communicating with another computer inside the battery pack and that battery pack computer handles all of that stuff. As long as the interface is the same between the car and the battery pack, it should be a drop in install. It would save no money or time having a different ECU for a Prius with a Lithium pack and a NIMH pack. In fact, I doubt there is any necessary additional programming for the ECU required as the battery pack ECU is what handles all the charging/discharging algorithms.


The much harder question is how can you justify going with a Prius II when for $800 more, you can get a better trim with a Lithium Ion battery pack. Hard to get a salvage battery for $800 and you're still missing out on the other features that higher trims have.

 

Moving from Two to Eco is a step down for many. You lose the spare tire, rear wiper and now the cargo cover.
The trim Three is s much larger price difference.

 

The PiP ECU should work then, I expect. They have a Li-Ion battery pack.

 

but you can't put li-on in gen 3.

 

the computer handling of ev batteries is way more complicated than laptops.