'06 Prius battery upgrade to LTO 55Ah cells

Rough Google translation
Terry, when I took these cells, I understood very well what they are capable of, I see recovery current in my machine from 20 to 70 amps in a short time. When I tested them, I rode them 5 kilometers at speeds up to 45 km / h and power up to 5 kilowatts, the power was still 6500, I could go further if I unplugged the battery terminal and soc would rise to 59, 5%. Therefore, I see no reason to leave lifepo4 cells as the main traction battery now. I rewired the original battery with a residual capacity of 3 Ah and am now waiting for a 0-300 volt charger up to 600 watts. For now, the battery is at my house and is being charged on a cell phone. I am planning to put it as an extra battery with soc replacement. Anyone know how to change soc batteries please give link to current project, i think you can do it with arduino if i am not mistaken.


Reply:

If you got 6.5kwh from the 70 x 13.5Ah LFP cells, from my calculation there was only 3kwh of capacity in the battery, so I must have the 6500 must not be wh but something else .... 6.5Ah maybe? Even if it was 6.5Ah, that is a lot more than you can get out of the 6.5Ah NiMh battery, I think getting 50% of that out of them before the Prius computer said "no more" would optimistic at best ....
It will be interesting to see if the LTO cells can hold the voltage up while being heavily discharged and see if that is enough to get closer to the full capacity out of the cells .... time will tell I guess

T1 Terry

 

The 6.5Ah capacity used out of the battery is still way ahead of the original battery, but I still think it is voltage related rather than the Prius computer limiting the capacity used. If you can spoof the voltage readings, you would probably get to use more of the battery capacity.
What threw me with the 6500 is I've never heard anyone talk about electric vehicle energy use in mAh before, that is just way more precise than any equipment used in a PHEV that I've seen.

T1 Terry

 

Interesting, thank you for that Yuriy. Sounds like there might be a problem then. With the extended range battery charging the existing battery, none of the recharge current passed through the hall effect sensor, but as soon as the NiMh battery was recharged by the extended range battery, the centre panel battery graph thing returned to green so the Prius computer sensed battery capacity by voltage rather than by current passing through the hall effect sensor ...... another possible problem to sort ...

T1 Terry

 

I toyed with the idea of setting up a voltage sensing relay that linked the traction battery to the 70 cell 40Ah LFP extended range battery when regen was sensed to share the high current across both battery packs ..... but setting the whole lot on fire cancelled that idea before it actually reached the first stages of experimentation.
I did get the whole vehicle to function on the 70 cell battery (when the traction battery went up in flames) by extending the module voltage sensing wires to reach each group of 5 cells. The system immediately sensed it had battery voltage on the correct wires again and it started up and drove ... well, till I hit a big bump and one of the wires came off and we simply rolled to a stop, no park pawl engaged so I could park it using the emergency brake and later load it onto a trailer to get it up to the workshop. So it wasn't a very long trial, maybe 5 kms, so not a lot of information was gathered :lol:

Things are so busy here with the Murray River predicted to flood big time, swamping the town lower area, and a lot of work fitting off grid systems ready for the power to be cut, I haven't had a chance to do any more on my battery upgrade project ..... maybe over Christmas .... as long as I'm not busy rescuing gear from our house and taking up to the workshop so we can move in up there until the river goes back down ... at the moment they are suggesting that might no happen until Feb .....

T1 Terry

 

It's getting wet here, the Murray River is rising faster than expected. The local neighbourhood group spent the weekend clearing and filling the wash aways in the track that runs past the back of our houses. The plan is to park the vehicles up on the hill behind our houses and get to Mannum that way .... a lot longer and rougher, but once the road is flooded over it will be the only way in and out.
Maybe next weekend I'll get to do some more on the battery pack, at least the workshop is well up the big hill coming into Mannum, so if worst comes to worst, we'll move in up here for a while.

T1 Terry

 

The worst is still headed our way. First peak should hit in around a week, the second close to Christmas and the third mid Jan to Feb ..... and then we have to add in if there are any more major rain events in Qld, NSW and/or Victoria the biggest parts of each state west of the Great Dividing Range. All of the water that falls anywhere in those areas ends up in the Murray River so must come past our place on the way to the ocean.
This is probably the dries continent ...... until it isn't ..... the land just isn't set up for big rain events ..... Mannum is probably 100kms from the sea as the crow flies, maybe 200kms if you follow the river, yet Mannum is on 13 mths above sea level .... this flood will take a long time to clear ....

T1 Terry

 

Just read my typo, that should have read 13 mtrs not 13 mths :lol: The water is really rising quickly now. They have built a flood levee about 2 mtrs high at the moment up one lane of our two lane main street for about half the towns length, up to the point the road starts to rise. The up market pub is on the river side so they have built their own levee around the pub, the old pub that has seen many floods is on the protected side .... well, until the river climbs over the levee I guess, then all bets are off :lol:
Spent the week end building a track and steps to walk from the back of our house up to the next level spot which would be about level with the roof. All of the neighbourhood group that will be cut off from town when the road goes under, spent a number of weekends clearing an old track that went up over the hill, then filled in all the wash aways and we have permission from the farmer to drive through part of his property to get to "Flood Road" that will give us access to the main road and the top entrance to town. The water has already cut the river side lane at the lowest point between our house and town, so we are expecting the road to be closed within a few days.
A video from last week if anyone is interested

Where they show the fuel truck in the fenced in yard at the end of the video, the water would be at around windscreen level now if it was still parked there

T1 Terry
At the very start of the video, two lions heads can be seen, they book end a park bench, just the very tip of the heads can be seen now.