Has anyone ever looked into Prius battery packs to modify for GEM battery packs. I ask that only because for every chevy volt on the road, there probably is 10,000 priuses on the road…
Haven’t heard of any. It’s a small step above lead I believe.
If going thu the trouble to re-engineer, might as well go lithium.
I can see no downside to this:
http://www.ebay.com/itm/182391788782?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Someone please buy one before I have to myself.
I’m drowning in batteries, but can’t stop looking at Bosch.
75ah seems just right. 20s= perfect.
Complete assembled package with bms port.
Brand new. Or so he says.
I’ll be glad to do the testing. Just send me one! 
Sorry for hijack. 
Price of course, might make Prius a viable option.
This certainly seems to be the way to go. The price of 6 new Trojan batteries is probably more money than this…
But will it work?
You don’t know what you don’t know.
Who will go first?
Anyone try these yet? I’m having battery issues and seriously thinking about these.
Prius or Bosch?
I sent the Bosch back as over priced and under performing.
The 75ah batteries were actually 60ah.
Not a big deal for used batteries. These were new, and priced as such.
The Chevy Volt gives you the most for the money. Nissan Leaf is more flexible as to mounting options.
Volt are packaged in 24, 18, 12, 6, and now 16s + 44s modules.
Leaf are 2s module and need to be wired into the size you need.
So what size volt packs work best for 72 volt Gems? I remember you were playing with an extra module to the leaf pack and getting away with the resulting higher voltage. Can you do the same with the Volt packs? I was also having a bit of brain fart. If these modules are designed to work in coolant, what about enclosing them in an antifreeze bath and in winter with its battery killing temperatures, pre heating the batteries with a circulating heater would allow output of 100% at below zero temperatures.
Still looking at buying a GEM. Found a really nice one on Craigslist I liked in Vegas, he stated he does not text. No problem….. I e-mailed him, G-mailed him, called over three times on the phone, left messages….. no answer. Finally, after 3 weeks his ad disappeared… weird. Looking at another one with front end damage. Does the older plastic front fit the newer 2012 style?
RussThe volts are water cooled. My current conversion uses a 1 piece module of 44 Volt cells.
Rewired it for two 22s in parallel, 110ah. giving me a 50 mile pack. Should be a picture on here someplace. I’ll take a picture of the left overs from a 2016 Volt.
As I didn’t have modify mechanically, it still has the hose barbs on each end.
I’m thinking just filling with antifreeze will get me by, as it’s stored in garage. If not, a small tank and gravity circulation may work.
My other car uses four 12s packs. 90ah and 24s. The water jackets were cut off to fit in small space.
Found my 44s volt picture,
See the hose barbs in the middle? Right of the 33 pointing left.
This is the nicest pack I’ve found. Only 1 in a 2016 Volt though.
It fit right in my EL truck.
This is whats left. three 12s and a 16s if it was split.
ps.
Yes, it’s all batteries on the pallet rack…
Volts are very common. I’m buying more. Can’t stop. Found a Volt with 19k miles for $1500 + 250 freight.
Paid about $2500 for my 2016.
A low mile 2014 is less than $2k delivered.
Enough to do four 25M Gems or 2 50M gems.
I have used a lot of them in boats. What do you want to know? Every one needs to be aware that ion-lithium are smart batteries and have charge control limits and on board battery diagnostics in some cases coupled with charger.
I’ve just been reading from this old post about using Prius batteries for a lithium conversion for a Gem and am interested in building one for one of my GEMs
I recently purchased a full battery from a 2022 Prius Prime that had 16k miles on it. I’m thinking of putting it in an etruck.
The full Prius battery pack has 5 internal packs with 19 lithium-ion cells each, so nominal voltage of these are 70.3v.
Questions:
I was thinking of getting a JK BMS 100A for each of the 5 packs and then paralleling them all… Thoughts?.. is there a better way or is this the best way to do this?
Would the 70.3v nominal be a high enough voltage to work in gem without reconfiguring/modifying the gem?
Would the 70.3v nominal be a high enough voltage to work in gem
[Short answer]
Sorry, but as configured, these are not ideal to power your Gem.
- 70.3v nominal is a bit low. It would be like running around on a tired/old lead acid pack. Performance will be on the low end(where is the fun in that?)
- and yes, Capacity is low. You will need to parallel several stacks to get any kind of range out of them. It makes for a very/over complicated setup.
Several others have tried the parallel pack/bms setup and have not had good results.
[Longer answer]
The operating window a GEM/GE motor controller is 68v (low) and 86v (high).
A quick look at what Prius is currently using for batteries looks like they are NMC stacks of 19cells and 22ah per stack? (1.7kw). (if I did my math right)
Even if you charged these up to 4.1vp/c this is 77.9 high and 3.2v/60.8. To use the full capacity of this stack/pack you will be pulling it down to 60v. This is the equal to driving around on a clapped out wet LA Trojans drained to 10v. Don’t even think about shutting your key off and trying to start up again. The Startup Boot check will not let you run the car below 68v (That is 3.57v per cell and still at 20%)
For NMC cells, the sweet spot seems to be 20 or 21 cells, even better is a 22cell stack.
If you can easily break up this brick and add 3 cells from pack#5 to a 19 cell brick, then it will be in a better voltage range.
but you still would need to gang up 4 of these bricks to make a reasonable pack. (and deal with complications related to multiple BMS units)
More than you wanted to know:
If going with LifePo4 cells, the sweet spot is 24 cells. (nominal V is lower for this chemistry)
Thinking about this more
Since I have not had hands on Prius bricks, And this is what you have already, it might be worth exploring them a bit more. Get in touch with your inner engineer and get creative.
If you can break up those bricks into individual cells, there might be a chance to rearrange them into something more convenient that you can use. Are these cells connected by welded bus bars or bolted?
If you can arrange them into 3 or 4 matched cells parallel first, then into series bricks that make sense. A single BMS will control this much easier than 4 separate BMS on their own.
Adding a single cell to the end of one of your bricks (to make 20 cells long) will give you a 4p5s brick. Stack two high, and 2 across will give you a stock performance level 80v/88 ah pack.
Figure out where they are going to fit into the car and what you can do to get the finished pack into that place.
From what I’ve read about these, they’re a lithium ion cell, and arranged in 5 individual packs with 19 cells in each pack ( 3.7vx19 cells= 70.3v)…then all packs in series for a total pack voltage of 351.5v.
Total pack is 8.79kwh
Was hoping the 70.3 nominal and fully charged to 79.8v would be enough juice, but I’m not opposed to breaking down the packs and reconfiguring them into a much better result…
I will dismantle the overall battery pack and see if I’m dealing with bolted or welded bus bars…if welded I’m not sure I want to do anything with them at all..
I like the idea of reconfiguring cells to the dealing with only 1 BMS.
What would be the ideal high end voltage to configure to…? If I take them to 22 cells (4.1v * 22 = 90.2v) would I need a “spoof” to run it?
I’m not familiar with this chemistry of battery… would it be better to go with a pack that is 22 to 23 cells and just not max out the charge, or do less cells and run up to max voltage on the charge?
You’ll need the spoof, but its easy. Just a diode on pin 1 to drop it a few volts. Once the controller powers up at key on, it never checks that pin voltage again.
Gems love the extra extra voltage. It’s like sticking a turbo on it.
You dont have to charge to full 4.1v…