Suggestions for Battery Conversion and more speed on 2015 E2

[frankjr]

I’ve been casually lurking in the forum for some time now, enjoying the discussions and picking up bits and pieces as I read from time to time.I’m amazed at how generous guys like @Inwo, @Old_Houseboater, @grantwest, @LithiumGods (to name just a few) are with their information, and time helping the forum users. A giant thank you in advance to all of you and everyone else that I failed to mention.

I have been telling myself that when it came time to replace my batteries I would seriously consider taking the leap and converting over… Well, my 2015 Gem E2 gel batteries are getting tired and need replacing. I barely get 8 miles out of them these days.

I love my Gem. I primarily use it to drive on the streets from my house to the Golf course, where I then play a round (or occasionally two if my damn batteries would last), and then back home.

I’m an engineer by schooling, have a garage full of tools, and love to DIY/tinker.

Here are my thoughts and questions for the knowledgeable of this group:

(1) The street/highway that I drive to the golf course is a 40 mph road. I only go about a mile on it, but it is a little unnerving to do 25mph when everyone else is flying by you at 50mph.
I would like to be able to go significantly faster on this short highway stretch. What is the best way of achieving this? Replace stock motor? Gears? Trans? Higher voltage battery pack with spoof? Magic Magnet spoof? Reprogramming? A combination of the above? Will the T5 controller fight me?

(2) When on the golf course, one of the biggest issues I have is the front tires have poor traction.
It seems to me the reason is a combination of the majority of the weight in the GEM is coming from the batteries and the passengers which are toward the rear, combined with the “conservative tread” tires I put on the Gem. Not sure there is much I can do to resolve that, but regardless of how I solve (1), I would like the “turf” switch to keep the Gem limited to around 15mph for use on the golf course, and I would like the “acceleration” in turf mode to be very conservative to help prevent wheel spin.I’m thinking this is something programming can accomplish?

(3) I’d like to be able to get 20+ miles of range if possible. For what GEL batteries cost, it seems like converting over to some form of recycled Lithium ION battery back is a no brainer if you have the tinker skills to do it. Am I crazy? Am I better off to pass on the enjoyment, fun and satisfaction of modifying the GEM to Li and just replace the GELs or does it make sense to go for it based on the above?

[grantwest]

Well I’ll say that a 7HP Ge Motor and 10:35
Gears with a 16kw Chevy Bolt pack (24 cell)
(High Voltage) Kit will get you 90% where you wanna be.

You would need
Chevy Bolt 24 cell battery ( that will give you the range and the HP you need) Dave or King happy can sell you one $2500+
The 7 hp GE or D&D motor will allow you to go 6k+ RPM
You will need a 24 cell BMS (Dave can sell you one) $300
You will need you Delta Q reprogrammed ( Dave can help you with that or sell u a new charger) $300 or so

So if you have the $ and feel like spending it you have the people here who can help you

[RS_E6]

It sounds like you already know the answer. Go for it! The LiFePo4 green cells might be a good fit for your parameters and price point. You’d probably be at the low end of your desired range but depends on how heavy your foot is. Bolt pack would give you plenty of range for a bit more.

[LithiumGods]

on a 2015 e2 this will be easy . your gem comes with a 10.35 trans and a 7.5 hp motor . you have all the gear and power you need . Just about any lithium pack will get you to your goal if you are not in too hilly of an area .you will need to have lithium profiles added to your charger . the easy way to increase your top speed is a mm , this with a lithium pack will get you mid to high 30’s . For better top speed and handling get bigger diameter tires . If you want to control more functions of your gem skip the mm and get a programmer . It takes a muck bigger effort but if your a tinkerer you will enjoy it .

The green Lifepo4 cells are an easy cost effective install (20 miles). about 1400. A bolt pack is top dog .2500-3500 depending on configuration (50 -60 miles)

[frankjr]

Conversion it is. Now, I just need to commit, and go for it!

Thanks everyone!
-F

[frankjr]

Hey @LithiumGods, I saw that you experimented with 5x5s Lifepo4 on a 2007. If I am interpreting your post correctly, I could yank my GEL’s, put in Inwo’s 5x5s Lifepo4. Since I was running GELs, I don’t even have to bother with changing charger profile, and hopefully I can do somewhere around 32-35mph with approx 18-20 mile range.

Sounds pretty tempting, and very painless?!?

So my question to all of you is if I do 15-20 miles 3-4 times a week, what would your best guess be for life expectancy on a battery pack like this?

Any other gotchas, or mods I should be considering if I go this route on my 2015 E2? Inwo was kind enough to sell me a programmer cable and disc.

Thanks,
-Frank

[LithiumGods]

you will need either a balancer , bms or shunt boards to keep your pack balanced .

the first 2 charges you need to monitor your shut off voltages to make sure your charger shuts off at the right time . I only tested one charger and cant confirm if all deltaq will do this . If not it is easy to have lithium profiles added to your charger .

once installed to will probably have to reprogram your battery display

[LithiumGods]

as far as longevity goes , I dont know . I only ran a set for a short time . they worked great . So no data on longevity . I do use 3 sets of these in my boat but they dont go thru the cycles .

[MikeKC]

How does a guy get respect around this place???
LOL - JK
@LithiumGods @Inwo @grantwest

[frankjr]

Man I blew it today,

I went to a salvage auction and a 2019 Bolt was on the block with 6400 miles on the clock. This thing was destroyed on all four corners. Good news, is that the dash reported the High voltage battery had 220 miles range in it after sitting for a couple of months waiting for the salvage title and all.

Started at $3250. It sold for $7000. Apparently there were a lot of online bids on it because it jumped in thousand dollar increments before I could blink. It closed before I could catch my breath.

Damn, I will get the next one!

-Frank

[Old_Houseboater]

Hmmm

I suggest you add a battery and go 84 volts. You will also need INWOs “spoof” and a magic Magnet. Total cost for 4 gage wire 4 terminal ends is less than 150 dollars and an additional battery
Advantages - meets all your goals. 2 hours to install, bone simple, Doesn’t destroy the ride. Stock motor loves 84 volts. This is my set up for over a year. 38 MPH with stock GE long 5hp 42 with RFF 7,5. 22miles range @25 MPH runs 35 with no effort Range goes south over 36 MPH (15/16)+

[frankjr]

That would work too, but I’m not sure where I would hide that extra battery in a 2015 E2 though?

[frankjr]

First off thanks to @grantwest & @inwo for all their help so far. I’m sure I’m driving them crazy! Im going with @LithiumGods suggestion of LifePo4.

So I yanked the batteries out of my 2015 e2 today, and decided to try to mock up what a BOLT pack would look like in the e2.

It is my understanding that a typical 20s Bolt module is going to be roughly 37.5" x 14" x 5". Here were my findings:

The 37.5" width is there INSIDE the seat riser. My concern would be actually getting it into the seat riser because of the bent over lip that the seat/bench rides on. Its my understanding that in a 4 seater GEM it takes some wiggling and manuevering to get it in the rear seat riser, maybe the same here?

I put a 37.5" inch stick in the bottom of the compartment and you will see it fits inside the cavity once you get in past the upper lip. Your results will vary with the whole module …

In the e2 seat, you will notice there is a black center seat support that the emergency brake also attaches to. The seat riser has a inward formed cavity to “recess” the emergency brake a bit. In my opinion, this is one of the hurdles that anyone looking to squeeze a bolt module into an e2 will have to deal with.

So the last thing I did was mock up a 14" x 5" wooden picture frame to represent a 2D (Profile) model of the bolt module. I then dropped that in and aligned it with the least clearance spot (the black center seat support I mentioned. You will see in the attached pictures that it clearly stuck up higher than the bench seat surface.

Having said that, I believe a truly motivated person, could probably find a way to make it work, but I think I’m going a different route. Awful tight in there…

[RS_E6]

Thanks for sharing, good info.

[LithiumGods]

i have not done an E2 . But I would pursue putting a shelf on the rails , front to back . From under the seats backwards to were the rear 2 batts are . I think @chris1 is doing this with his bolt pack now .

[Inwo]

Yes, basically tip your mock-up back on top of frame.

[frankjr]

Damn, I knew i pressed post to soon! I had more pictures.

Here you can see the tape coming from the vertical seat support up front toward the back.

Length wise: a 20s bolt module (37.5" long) would still be too long I believe. The spat on my e2 is just about at the 38 mark on the tape measure. The problem is that the spat isn’t flat, only at the license plate portion and that isn’t 14" wide. Just to the left and right of the license plate it cuts inward a bit.

Pretty tight in my opinion.

Height wise in the tunnel is pretty good clearance. Looks like about 9" clearance above the alumninum.

My conclusion:

Everything is tight, but as I said earlier, I think a motivated person could get it done. If you took one of the stock Bolt 18s modules I think it would be perfect for the tunnel with a 6s somewhere else under the font seat. I don’t have the dimensions of what a cut down 6s would be, but the smaller size might allow for it to placed somewhere under the front seat avoiding the center support beam… maybe!

Using proportions to calculate an approximate length of a 6s bolt module works out to 12.5" long. That could probably be stacked on the 18s going through the tunnel, and fit perfectly in the front seat compartment.

Anyway, I just wanted to post the rest of the pictures for anyone trying to figure out a plan!

-Frank

[frankjr]

This e2 is my fun car for going golfing in. I decided the Bolt is overkill for my usage.

My plan is to go Lifepo4, completely under the front seat of the E2. My plan is to layout 28s as follows:

[grantwest]

^That looks cool ^
See what you can do to get up and over 80 volts your car love you

[Inwo]

28x3.2v. Lifepo4 are the same voltage most of the way full to empty.
3.4 for a while on top. 3 is dead.

Makes reading soc difficult.