Extreem changes

Yes I think this has been done, but I do not know all the details. Keep in mind that the battery pack includes several voltage, current, and temperature sensors. Form all this information the battery ECM decides what charge and discharge rates it can use, and how fast to run the battery ventilation fan. I suppose that a second battery in parallel would cause some changes, but the ECM might have trouble making sense of them.

I really admire the idea of the hybrid drivetrain transplant, and hope you can take photos and write descriptions of the project.

 

I would not mind seeing such photos Fred.

As an owner of both Prii in the past two years, I'm most curious about mods and the inner workings of such a cool vehicle.

Even if it is in pieces.

--TSK

 

I don't see why you can't hook three in line.. just guessing.. my knowledge is primitive to toyota's, but I have built a hydroelectric system that has been in operation almost 20 years now....

The system reading current, voltage, and temp should not be adversly affected by having a bigger bank. I don't know if the system would have any problems at all.. or maybe it will merely see everything the same? The reality of it would be that it would just take longer to charge up the whole bank and longer to discharge it?

I would try to get ahold of a toyota engineer if possible, but and easier route may be to talk to the guy who has already altered it successfully?
http://cbsnews.cbs.com/stories/2005/08/16/...ain781291.shtml

He may not want you to steal his thunder...... a toyota guy may be more honest?

My hydro systems were not near as complex as toyotas computers, but I could use 4 golf cart batteries, or I finally went to 6000 lbs of lead calcium telephone batteries and I didn't have to change anything else.
The voltage would still be the same... current wouldn't change because thats based on the cars demands... the only real difference I see is the time factor.... it will take different time lines to fully charge verses fully discharge with a bigger battery bank.
I would love to see someone try it... sounds like you could just be the guy?
Not very many have the means "and" the knowhow "and" the money to try it?

 

Currently, the battery SOC is determined by the voltage at each module. The battery ECU in the battery cage takes these readings and from them determines battery SOC and condition.
Adding a pack in parallel at the ends could accomplish one's goal, but may not be perfect, since only the original pack's condition would be monitored and known.
Also the current flowing into and out of the battery is also monitored. I'd say it would be best to attach the additional packs as close to the original battery pack as possible, with the current monitor outside the connection, so the current monitor reads current flow into and out of all packs.
The connection wiring should be adequate for the voltage and current involved.

 

What are your opinions on mixing the battery types?... if you can get a gelcell set as close as you can to 201 volts?.... 17 X 12v = 204 volts... that may do it?

I wonder what the resting voltage is of the original battery pack?
If the added batteries were consistently higher... they would want to dump energy into the lower voltage bank, thereby overworking themselves...
thats why its bad to mix new and old batteries.. the old bring the new ones down to their level.. .but in this case its a bit differerent... we are really dealing with voltages.

If the added bank was a bit higher in voltage.. they may wear out prematurely?