What did you do to ur Gen III Prius today????

What do you mean by single? It only beeps once and then stops? I’m hoping that’s an option!

 

Yes, that was the FIRST thing I did when I got techstream working!
WHY would you need it to beep INSIDE the car?

 

replaced the 4.4kWh battery in my PIP with 8.8kWh of batteries, picture shows half the modules replaced.

 

Nice! Despite the weight increase you might be able to get another dozen miles or so - all electric now. Wonder how it affects the onboard charger and cooling ....
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actually, they are a weight reduction! I'd say at least half the weight of the original modules. The thing is, the more capacity the more heat is dispersed. I plan to find out more once I get things all buttoned up but I really want to see if they take the same amount of time to charge with a level 2 as the car did with 4.4kWh.

 

Thats awesome, i was planning to do the same with a non pip. You connected the new ones in parallel to the old, correct? Or are the new modules double in capacity compared to the old? Im not familiar with how the batteries are arranged in a pip.
Any noticable mpg increase?

I imagine it would be incredibly useful in summer heat, when mpg drop significantly due to the additional heat on the batteries from the cabin temp. I get high 30s or low 40s in 108degree dash reported temp. But 50s when its 90 or lower. Despite AC usage staying the same and and driving over 85mph on the highway on my normal route. Im convinced the heat kills my batteries performance.

Amp draw is another thing to consider. The terminals on these cells are tiny and break constantly when mildly overtorqued. I tried to charge one manually and they got really hot because the skinny terminal bolts physically cant handle it. They arnt designed for high amps, so this might be the reason they suck in high heat situations.

 

oh no, removed the old modules and replaced them with the higher capacity lighter modules. no data just yet.. still putting all this together.

 

Ah ok, i presume the amps are doubled and not the voltage right? If so, is the diameter of the terminal bolts thicker?

 

How about same volts, same amps, for twice as long? No change to bolts.

 

Haha same volts and same amps AND twice as long? You cant double wattage without increasing either volts or amps because watts is volts × amps. So im curious as to what they increased to double their 4.4kWh to 8.8k, because that makes a big difference.

You increase voltage, you basically have an electric motor that spins twice as fast. But doing so alters everything that relies on the HVB because the computer sensors rely on detecting the voltage for stuff like to know when to start or stop charging. Then you run into the hardware issue of if the electric motor can run at twice its speed and power without overheating.

Im most certain that they doubled the amperage and not the voltage, but i need OP to verify with a multimeter if still possible that the old and new ones read about the same volts. Doubling the amps increases capacity, but amps unlike volts, you need a physically thicker medium to travel through. Only drawing a bigger load would this matter, otherwise youll burn your medium. But OP wont have this problem because the car is only programmed to run with 4.4kw anyway, but the heat dissipation would remain the same if the medium is the same size. I was under the impression he put extra batteries (connected in parallel) which the extra material used to connect them would divide the load of the heat created by the flow of electricity.

I plan to do the same as he did, but moreso adding additional batteries in parallel and see how it affects my system.

 

Before 'splaining to me all that, did you happen to notice that little h in kWh ?

 

What are you implying? Maybe im ignorant of what that means, but please explain because id like to know how the h in kW changes anything i said previously.

 

this is the thing... I feel like no one has gone down this route I am or anything with modifying the total kWh or aH of the cells because of the same thoughts regarding how the car is coded to handle what came from the factory.

what if I said the ECUs are smarter than we give them credit for and that they are almost in a way "smart" and able to accommodate changes then basically tune themselves to adapt to additional modules for the battery.... and... even engine upgrades?



my advice and an avenue I am still driving down, obtain the bZ4x battery.... the newest, highest kWh battery with cell composition that will work with the Prius PIP! This is how I plan to get above 50kWh and possibly in the 70kWh range! Now compare the battery size and output to the first Rav4 EV.. which has cells that work in the PIP Prius...

 

You know... the thing is.. the internet has a way of making it so people can't truly know what anyone really has in-depth knowledge of. So one could be attempting to ensure they are interpreting your words accurately versus any ignorance implications... just my $0.02

I'll also say, I spent a solid two weeks or so going back and forth with battery specs and entering them on the site below in an attempt to figure out how many cells I would need based on their specs to get to the V and all else which would work in my PIP while increasing the overall kWh to be what I need. The ah plays a role in the numbers as well.

https://power-calculation.com/battery-storage-calculator.php

 

I think you get the idea, doubled capacity means increased kw hours which could mean increased operating time when connected to the original load.

You don’t need bigger wiresize or bolts when the load amp draw stays the same. The load can then theoretically run for more “hours” or fractions of hours when you have more capacity as defined in kwh.

Where this gets dicey is when blackj says he believes the existing controls will know what to do with more amp hour capacity. Can the controls charge longer? Probably unless they calculate the battery must be bad because its too slow to charge. Will missing or inconsistent temps and module voltages kill the experiment? Very likely. Does Toyota have a learning algorithm for significantly slower than expected discharge rates? Or will this idea work at all?

 

The h stands for hours, a unit of time. While kW is a unit of power, kWh is a unit of energy, which is power integrated with respect to time.

Compared to an n kWh battery, a 2n kWh battery could be any of:

• A battery delivering the same amps at twice the volts for the same amount of time, or
• A battery delivering twice the amps at the same volts for the same amount of time, or
• A battery delivering the same amps at the same volts for twice the time, or
• any intermediate combination where the product of volts, amps, and hours comes out the same.

 

Will be using the OE module cooling and temp sensors, hoping to have the dc fast charging parts in hand next week, plus these have already been tested and proven to work without issues. I just need to finish the install up and see if all of the hypotheses on my end were accurate or not! I'll keep yall updated!

 

Thats where im lost, because a battery delivering same volts and amps for twice the time would require its capacity to be twice as much. Which i was referring to capacity in terms of amps, because thats how i see it as, and the volts in terms of speed of which the amps flow.

I think i understand your thought process. Nothing changes, just the battery itself is larger thus allowing for more overall capacity but no difference in terms of how many volts or amps exit out compared to before. There would be no functional difference in this case because if you cant extract extra amps for when load calls for it, why double capacity? Its equivilent to doubling a soda bottle size, but keeping the bottle neck the same. Except in this situation we would be filling and drinking while we try to keep its liquid constantly half way full. Perhaps these batteries were made for a system that requires double the voltage?

And perhaps i might be wrong, and that a overall larger battery capacity can dissipate heat inside it much better to where it does provide a significant advantage to one half its size, but im still wondering if the size of the terminals and bus bars are adequate enough to provide a good flow without being the path of most resistance for the electrons to travel. Thats what im curious about most, since OP basically doubled his battery size but those things stayed the same.

 

Double the size and it can store twice as much. Since the load determines the amps the same load can last longer. That is why batteries are rated in amp hours.

 

Exactly.

Exactly wrong. The speed of electricity doesn't change. Volts would be somewhat (not perfectly) analogous to water pressure. Amps compare to pipe diameter. They produce liters per minute or volt amps, or watts. Neither has anything to do with capacity. That's amp hours, or kilowatt hours ... or in the not quite perfect plumbing analogy, liters.

A battery that can provide 2,000 kW of power might store any number of kWhs. And it doesn't necessarily send that many kw through the wire unless the load (motor, lights, computers, etc.) demands it. It sends whatever is needed up to the 2,000 kW limit. Just like the big honkin' transformer that feeds your house.

In a non plugin, that would be true. But you seem to have missed the fact that the car in question is a plugin and they do not work like your description. They draw from the battery and only the battery until the battery charge is low enough to require that the ICE start up and propel the car. It stays like that, running like a regular hybrid until the driver plugs in the car again so he can drive on the electric motor again. With twice the capacity in the battery, one can drive twice as far before needing to run the engine or plug in again.