NIMH To Lithium Prius Hybrid Conversion P1 of 3

This first part battery build gives the basics of how I made the switch, how much, and any differences found.

[@eby6114]

Part 2 The Build is up

[@eby6114]

@ki0ng It was suffering from a bad battery so no it doesn't give better mileage but it did restore it normal. Playing around I've achieved 60 city 50 highway. I don't hyper mile in general in general I only get 40 city 38 highway. Before 34 was about the best I could do with a bad battery

[@eby6114]

@ki0ng Only if your driving with that in mind. Anytime you mash the accelerator it automatically kicks the gas motor in defeating the hybrid. Feather footing will get you there.

[@eby6114]

@ki0ng The true potential of hybrid driving would be charging at home using out and about

[@eby6114]

@ki0ng That's true and not sure how but there's a way to override the switching from battery to gas giving you full electric. Sounds like a project!

[@chrisallen649]

@@eby6114 Did you work out how to hook the switch up to keep the engine off?

[@aomanchutube]

I read some harsh criticism about this project, but man, I really needed to see this. 5S 2P seems to work with these. I just saw a test by another KZbinr that shows continuous 1kw where the usual draw is more like 400W at like 30 amps. I noticed up to 100A on very aggressive regen by stopping hard. But yeah, normally the charge/discharge is pretty low like in the 30A. The specs say the battery is 20kW and the motor is 45kW. So if each of the cells I'm planning on using can do up to 200A discharge continuous then it should do the job just fine.

[@eby6114]

The only negative thing I noticed was it appears that the batteries are used to push the car down the road even when your on the interstate. To me the ICE should have been used as a mechanical only but it would appear that the engine is forced to make mechanical and electrical all the time. The batteries appear to buffer the electric also instead of going straight to the electric motors. If I ever find the engineer I'd probably slap them upside their head like the three stooges. You should note also that in other countries you can click electric only for short spells but in the US you cannot however the function is there on the computer it's basically 2 wires that need to be shorted so basically cut extended and a intermittent switch used. It also has to be pushed before the ICE comes on. Cheer's. If I ever catch up it'll make the final video.

[@aomanchutube]

@@eby6114 this is actually one of several combinations for making a hybrid. The series hybrid decouples everything mechanically, the parallel hybrid has the motors assist the engine mechanically. Eitherway, the whole purpose of the hybrid is to take engine power and level it... the engine humming along at some constant speed is the ideal system.

[@vinnyboywo6571]

I'm very interested in your rebuild with the Lithium cells. I have not yet seen pt 2 or 3, but I would like to see a schematic of the banks. Also, it would be nice to know where you sourced the cells. I love my gen2 model and when my pack starts to show it's age, I would like to build a lithium replacement. I am an electronics engineer and teach electronics engineering in a college, so not only do I have the skills, I would love the diy project. Excellent video. Just left me wanting more 🙂.

[@eby6114]

Part 2 is in the works. Waiting on part 3 to accumulate a few more miles but all lights are green so far. The build should be right up your alley! You could probably give me a few pointers on the matter given you experience. This is my first build for a Prius so there's already numerous things I'd change hindsight 20\20

[@perniciousprogressive8333]

I just installed a Project Lithium Nexgen battery to one of my five Gen2's (stupid expensive) and I kept thinking there had to be a way to build one from individual cells, and sure enough, a week after the install I come across your build. lol Excellent job! I could've built three of yours for less than what I just spent on theirs (sold by the guy who developed the Dr. Prius app). Don't get me wrong, it works great, but beyond their fancy 3D printed modules, not much different from what you built I'll bet. Thanks much for the inspiration! Getting tired of regenerating the old chemistry batteries. It does work fine, but the energy density of the lithium build doesn't compare. Also don't have to worry if I don't drive it for a couple of weeks. The old chemistry really needs to be driven regularly to stay in good shape. And then there's the wright, and the cooling, and the, yeah, you already know. ;)

[@Thissandthat]

This is super awesome! Can’t wait for the update

[@grahamwinn979]

Engage Warp Drive Scotty.. Let's check out those Dilithium Crystals.. A cost effective upgrade.. bringing the car into the 21st century. The project actually works..

[@eby6114]

I have another special video hopefully coming soon.

[@emmanuelegel21]

It’s just amazing. I always think to do the same with my 2007 Camry Hybrid. Thanks for this video.

[@eby6114]

Part 2 the build is up

[@emmanuelegel21]

Question my Sir. How much current drives the 2 35S Bms? Cause, the hybrid motor during the charging can drive 50A and more

[@eby6114]

@@emmanuelegel21 231 V nominal

[@pritambissonauth2181]

Thanks for sharing your project to convert the NiMH battery pack of the 2nd Gen Prius to LiFePO4 chemistry, from [1P168S ] to [2P70S] at the cell level. I am watching this video again after having watched parts 2 & 3. I watched so many videos on the Toyota NiMH HV battery, its the first one pointing to the "Blocks" in the battery which is [1P12S], others did not mentioned that. The 'M' in the BMS for the Prius stands more for 'Monitoring' rather than 'Management' as there is no balancing circuit/feature in it. I now better understand why my wife's "Prius C" performance had degraded without giving any alarm codes, the cells would become unbalanced with time, this model has only 10 blocks or 20 NiMH prismatic modules, mileage was not that an issue, seems unchanged. I do have a few questions: 1) What is the maximum voltage per block you have observed? On another video on KZbin I saw it rise to 19.1V 2) What is the maximum discharge rate of the cells you are using? Are they rated for the continuous or peak values? 3) Did you observe better mileage with more battery capacity? Definitely you can mount your cells vertically allowing for more space between them and thus better air cooling in the same pack. A crazy idea would be to have the cells submerged in oil for more efficient cooling.

[@eby6114]

I've seen yes 19.1 but this is not true voltage since when you aren't charging it goes back to normal. 1 amp discharge continuous x 2P x 70 so around 140. Cooling isn't really a problem once you work out the use of the automatic Prius blower and spacing. I thought of oil too. Every wire can come from above so being inside a oil bath would be fine. Otherwise hollow aluminum spacers would be plenty. I probably have at least 4 inches or more of extra space inside the battery box. If I had to do it over again I'd make one long string and add the Prius bms but not my own and just monitor it once a month. Cooling can also be achieved but running a 3P configuration dividing the current across 3 instead of 2. 1P would not be sufficient.

[@pritambissonauth2181]

@@eby6114 I made a little mistake above, I should have said after watching part 2 and 3 more videos from you. When are you releasing part 3? I am also thinking the inverter has no way of knowing that there is a bigger battery pack connected to it in your setup, it could have pulled more energy from it during acceleration and dumped more energy into it while doing regenerative braking.

[@eby6114]

@@pritambissonauth2181 I am currently working double than normal. I haven't had a break in a while even to make a simple video. I'm trying to add a third business while running two, then I'll drop one leaving two. Yesterday I worked 4:30 am to 7pm lol. I reached the point where I felt confident in the design about a week ago. Plenty of highway trips and abusing the poor car without any issues. Packs still within a tenth of a volt etc. It should be a fun video. Hopefully once I finish some schooling fix my big truck etc (putting out fires) it'll be the second video I do. Thanks for the patience

[@pritambissonauth2181]

@@eby6114 I wish you the best

[@ToolsOutsideTheBox]

Very interesting

[@rjright7373]

My only concern is Lithium doesnt like cold as well as NiMh battery. You would have to park it in a warm garage during winter, above 10 and preferably 15C. Other than that looks great and once the car warms up I assume it would be ok but I would insulate it perhaps.

[@eby6114]

Or add a small heater. A heating pad would be overkill.

[@charleshorseman55]

If you get the EV switch, you can keep the ICE from charging the batteries until they have self-heated from discharging imo.

[@eivis13]

Cool, glad you had the money to try some version of this mod. Also, was it me or did you use steel screws for the batteries? That may be the reason for the higher voltage drop on some cells than others. More conductance = less voltage drop. You increase conductance by either more material or changing the material for a better conducting one, if possible aluminium, otherwise brass should do nicely.

[@eby6114]

Tough to find that thread with anywhere. Yes screws, nuts stainless steel. It was the only thing I could find. 4mm x .75

[@1doalbeck]

Good work

[@eduardomag]

Which specific cells are you using?

[@grandmasgermankitchen7850]

Fantastic idea. So you said you that you wanted it to be safe. Are you worried about having a fire? Thanks

[@eby6114]

Good question! This is not your regular lithium batteries. It's LipePo4 or Lithium Iron Phosphate. Sorry I didn't mention it yet.

[@SC-ym5zu]

How does the new battery do under heavy regen? Do any blocks go above 18.25 volts?

[@eby6114]

Never have gone above 16.5 volts. I really need to find a hill that's a few miles long. I'm here in Florida where there's not many hills that are worthy.

[@imalin4638]

Thx

[@minorukurata]

Congratulations, I was designning with LTO battery, but Im seeing with 32650 its more cheaper to do it, I guess with minimal 70S1P will work because the original battery only peak at 24kw, im trying to do it with 3rd gen but using plugin version bms and charger

[@eby6114]

Very nice! Yeah there's room for improvement on a lot of things out there.

[@minorukurata]

@@eby6114 yes but nice jobs, what mpg did u get with this, with LTO will use the whole discharge curve with lifepo4 90% wich is great, so prius bms will use 40% of 90% like 1kwh util in my calculation,

[@ericpowers7704]

I'd like to see State of Charge as one of the monitored parameters. I wonder if the car sees a big swing in SOC. I know you don't want to release mfg name of cells, but how about some basic specs? 1) Capacity 2) Nominal voltage 3) Maximum continuous discharge amperage 4) pulse discharge voltage. For example I have some cells that seem like they would be good candidates? 1) 3.3v 2) 2.3 Ah 3) maximum continuous discharge:70 amp. 4) Pulse discharge at 10 sec: 120 amps

[@eby6114]

Soc saw a o difference which I found odd as my voltage did increase if ever so slightly. 3.2 nominal, 6000ma stated 10c I'm more comfortable with 7c so the amps is around 50 surge times two or that would be a hundred surge for the combined.

[@shlomom2882]

What is your opinion about this transformation after 3 years?

[@eby6114]

Would love to tell you but I was traveling 5 hours from Miami to Wildwood and some people, Spanish came to my house and offered me money for the car, more than I could refuse. Never had that happen before. It seemed good. Had decent range. Battery only usage for a few miles tested around 2am so I didn't piss off anyone. Never got hot. If I had it to do over again I would have doubled the capacity. Ended up getting a Suzuki xl7 7 seater 4x4 2 ton suv. I was pouring the miles into the Prius close to 300 miles for some schooling for a while.

[@minorukurata]

how reliable was the conversion ? Is stiill working with 32650

[@eby6114]

Still working. I've been going work around 80 plus hours a week so I haven't uploaded in a bit. It got boring to check the cells as the where holding up just fine

[@minorukurata]

@@eby6114 ook, I just want to try ur type of replacement and also I have 3.2V 120ah with 70 cell as a plug in hybrid and charge externally, if will help to reduce more the compsunution

[@minorukurata]

@@eby6114 there is a chinese company that is selling lithium replacement projectlithium.com/products/prius-lithium-replacement-pack but its too expensive

[@eby6114]

@@minorukurata did you try AliExpress?

[@julianjiron6823]

Hey thanks for posting these series of videos! Whats the rated ah on the individual cells? I looked for the Basen cells the max rating is 6ah. Battery Hookup has 8ah but im doing the math and dont see how your getting 2.2kwh. Im doing the math wrong i think because im calculating 1.7kw ha at 8ah cells. Lmk thanks.

[@julianjiron6823]

Hey I was reading the comments and noticed you mentioned the cells are 6ah. Not sure why im getting 1.7 with 8ah batteries. Im gonna do some googling. Thanks

[@eby6114]

Sorry very busy in the weekends. 3.1volts pers cell x 6MA so 18 watts per cell x 140 is 2.6 kw for the lack I've built. Pt 3 is coming perhaps next week. I have a few more test to run. Thanks

[@peng28]

what type of your bms ? thanks you

[@eby6114]

The only thing I could find was 2 bms run in series. I hooked it up but ran it without it and monitored it with the Toyota BMS. It never got past .2 volts out of balance and thats possibly due to steel nuts and washers

[@ahmadalami9640]

Do you feel you have more power now? Has your fuel mileage improved with this new battery?

[@eby6114]

I can tell I have more power but the whole reason I put these batteries in was the nicads were failing so the same is true on the mileage. It went back to the 40s and 60s mpg

[@ahmadalami9640]

@@eby6114 I mean compared to before when your nicad battery was still new?

[@eby6114]

@@ahmadalami9640 sorry I didn't have the vehicle until after at least 125,000 mi then it started giving me a few hit and miss problems at around 160,000 and then by 180k the whole system was shot. It was cheaper for me to replace the whole thing with lithium than buy new or even buy a reconditioned battery

[@jakegoakes]

I can't find where you bought a 35s bms

[@eby6114]

AliExpress

[@jakegoakes]

@@eby6114 thanx for getting back to me I've looked high and low on AliExpress all I can find is 32s

[@eby6114]

@@jakegoakes US $160.00 | 5S-35S LTO Battery BMS 100A Common Port Circuit Protection Board 2.4V Lithium Titanate Battery BMS PCM 12V 72V 60V a.aliexpress.com/_mNFlhsE

[@jakegoakes]

@@eby6114 yea I saw that one I guess I just need to message them and they will me a lipo4 version I didn't see that they had the Bluetooth app like yours did

[@AJTarnas]

around 2:50 you mention the battery capacity. but you say "kilowatt" instead of the proper unit for energy, "kilowatt-hour". great stuff here. the nexcell / dr prius blades are more professional. but they are waaaay overpriced. LFP cells for this project are in the $600-$1000 range rn. versus the nexcell blades which are $2300 and not even in stock.

[@andrewyu7403]

You really should not replace the original traction battery but instead keep it charged through the secondary lithium battery pack.

[@eby6114]

It was shot. Most of the cells where bad thus the entire replacement. 16 year old cells.

[@Loky313]

Where is part 2 and 3

[@eby6114]

3 will up after 10 000 miles. Part 2 is here kzbin.info/www/bejne/gnfNk6yGZ8eIhJY

[@hjlpoppp]

the lithiums are not good for constant recharge so this is a downgrade