Hey All
It’s time to replace my batteries in my 2002 e4. I live in Southern California ( Orange County ) . Looking for ~20 miles , fully loaded with 4 people , mostly flat terrain .
What are the best options out there right now? I’m open to a bit of diy but I roll with my kids in this thing so looking for something reliable and safe .
Done some searching and looks like @LithiumGods has a new all in one pack , @AssyRequired did you ever build anything ?
Thanks for any pointers
I was wondering what happened to you.
How is that gearbox working?
Yes, much has happened since last you checked in.
That SDI22 is a pretty slick pack.
Your car is 02 correct? It can be a bit tricky fitting them in, but a couple of options.
There are 2 good options for your Gem. The mighty might will have a 20+ mile range and the Samsung 35+ mile range. Which charger is in the Gem?
I will be stocking both batteries in Orange county and Carlsbad starting next month
Hey!!! Gearbox is going strong . Disc brakes are working great. Pedal replacement fixed my electrical gremlins . Didn’t leave my batteries on a trickle charger for the winter and that killed what little life was left in the gel batteries .
I have the delta q. Are both these options using cells from an ev or brand new cells ? Also what’s the ah rating and nominal and burst discharge on these packs ?
Samsung battery using SDI EV cells. NIB Factory laser welded battery 94ah, 22s, 200amp bt bms with 450a short circuit trip rating.
100s sold and working in Gems.
$2950 shipped conus UPS tomorrow.
Charges to 85% with charger as-is. Spoof it to charge 100% or send charger to me for lithium specific programming.
I believe Byron has the same battery for sale in 64ah. (one only) About 20 miles. For what I think would be much less money. 1/2 maybe.
@AssyRequired
He won’t want to go around us, but it’s fine. He is our support tech guru. 
@LithiumGods ???
I made this change a few months back and it freed up space for a subwoofer. Not very difficult to do.
I live near Murrieta if you want to check it out
These are new in box batteries. Factory built, unless custom is requested.
Until stocked in Ca, they can be shipped ups.
Hey All,
I’m pretty convinced that @Inwo and @LithiumGods “Mighty Might” pack is going to be the easiest drop in ready solution that will give me everything I need. But being an insufferable tinkerer, I came across this pack that I may try putting together.
Envision NMC 48V 98Ah 4.2kWh | Brand New (greentecauto.com)
These Envision NMC cells come in a very interesting packaging. I could purchase two of these 4.2kw packs and pretty easily disassemble them and reconfigure them to be 20s2P. That would give me 75v nominal 82v max with 98ah in a package that is about 15"x8"x13" which should fit perfectly up front.
The packs seem easy to work with, they are literally held together with a strap, and have easy terminals for me to create bus bars or even try to reuse the existing bus bars.
Couple questions
Any other thoughts from the experts?
Thanks for the advice!
-Jeff
what’s the max and steady state discharge rates for the packs?
Good question , they are saying they can easily support 1c continuous and burst to 3c . Which should give me ~200amps continuous .
Interesting battery. Being pouch based, they remind me of when the gang was messing around with Leaf packs and their cousins.
The modular design hints at the possibility of interesting options. IIRC sometimes it can be tricky at getting the pouch cells back together once they have been released and expand a bit. This battery actually says “Easy to take apart”. Maybe this one has potential?
Shoot- Why stop at 2p? Order up another (3rd battery) and arrange the cells in a 3p24s config? One would need to find room for a 30" pack(rough math).
I don’t think the Gen 1 cars have this kind of room in the car. #nevermind #forgetthisthought.
Is this an ideal voltage setup?
It depends on what target V you are going for. It is well known by the hot rodders here that these cars wake up and perform very well if you run them at higher than stock voltage. Running within the stock v bracket (or lower) is not going to produce the wow factor of a supercar.
Reconfiguring these to a 20s puts the lower V at 60v. This is way below the operating V of the car and the charger doesn’t like to start below 68v. I think you will be bouncing off the turtle and limping home quite a bit.
You would be far better off at a 22s and setting your lower threshold at 3.1 (x22/68.2). HighV will be 4.0(x22/88v) while not maxing out the pouch charging it to 100%. I am only guessing since I haven’t seen the data sheet on these.
Two of these (as is), makes for ~96v. This is running a bit too high IMO for a Gen1 car and T1/T2 controller. While some have done it, It seems to be about 50/50 odds that it will be glitchy if it doesn’t let the smoke out on first click.
BMS be able to be reconfigured for this?
Sure, the JK should be able to handle this.
There is quite a bit that goes into being a pioneer and being the first to play with new cell tech and packaging. Also be prepared to totally fail and scrap the whole project and go another direction. This is something both @Inwo and @LithiumGods (as well as many others in the group) have done many times in the quest to find what works and what does not.
If you haven’t spend time in the archives it i well worth the visit.
@AssyRequired , thanks for all the great advice.
I think 22s2p makes sense, should still fit right up front. Max voltage is 4.15 so that gives me headroom and with 98ah I don’t see myself ever charging above 70-80% anyway.
Really unsure about how “easy to take apart” they really are, but it seems like a fun project. Need to read up more on compressing pouch batteries though.
Also good thought on the JK BMS, I’d been looking at Daly and others that were not programmable and wasn’t seeing any good 22s options. Seems like this will work fine.
The batteries arrived today. Physical assembly was much easier than I expected. Each pouch cell essentially had a plastic carrier, aluminum heat transfer plate and then foam separator. I cut the metal straps and easily took 4 cells out and reassembled with a couple 24" clamps. Its currently being held together by some 200lb zip ties until the replacement metal straps arrive. Online the top panel looked like a PCB board, but in fact it was just some interesting 90 degree angled bus bars shrink wrapped in plastic, so I simply cut what I needed with a knife and screwed it back down.
Tomorrow, I plan to tackle the JK BMS. Does anyone have any recommendations on where to place the thermostat wires in the pack? At the moment I was thinking attaching to the copper plates squeezed between the packs and I’ve read mixed thoughts on letting it get squeezed against the pack itself.
Now for the bad news, as @AssyRequired mentioned, I guess I need to be willing to throw this whole thing away. One of the packs had a 30A fuse attached to it at the negative terminal. The seller stated this thing would easily support a sustained 1C and I haven’t heard of a .3C NMC battery. I’m reaching out the seller to learn more, unfortunately there really wasn’t any markings on the cells other than this barcode. Hoping its use case in the Cummings Truck was very low amperage and the 30A breaker was more for the original BMS and that the cells do indeed have plenty of headroom.
Here’s some pictures
Finished Pack before BMS
Two packs getting ready to be merged
Looks like it will be an interesting pack.
Are you going to try and bolt it together as one module?
How heavy is it going to be?
According to the docs I’m guessing it will be ~120lbs?
Appx dimensions of finished cube (estimated)
8.75w x 12.75h x 20l
You might want to consider keeping it in two pieces until you actually get it placed just for convenience. Wire the BMS on the bench with a couple of nice quality plugs and plug it all together in car.
Just thinking ahead…
