Double Drive Batteries/Range

[Jusntil6935]

Is it possible to install a second drive battery pack atop (and in parallel to) the resident battery pack of six to double the vehicles range?
And yes, I am okay without a back seat and hatch compartment. I can Not find any information about wire harness or connections to/from
the drive batteries. The info on these EVs is very sparse.

Thank you,
JT

 

[NORTON]

Sure, just strap it on the roof.
You'll need HV wires, Low Voltage communication wires and coolant hoses up there also.

Or just buy a Bolt. +3 times the battery size, rated for 238 miles of range and very, very affordable right now!

 

[SparkE188275]

You could search You tube. I think there are some videos posted that show a Spark EV battery upgrade.

 

[NORTON]

You could search You tube. I think there are some videos posted that show a Spark EV battery upgrade.

Please post links. I'm doubtful.....

 

[Jusntil6935]

I guess sentence comprehension is not a requisite on this site.
Saying I'm okay without a back seat and hatch infers That's where I'll be putting the batteries
and as far as connecting some hoses, comm wires, and high voltage wires, wow, that sounds Really tough too.
If you don't have anything constructive to say keep your stupidity to yourself.

For the others, thanks for your input.

 

[Kermit]

I saw a RAV4 EV that had a trailer with another battery pack on it. I don't recall if it could disconnect for shorter trips or not. It appears he is putting a camping trailer on top of it. Not sure of the Spark towing capacity but an interesting idea.
https://www.youtube.com/watch?v=s9eU_GkOIbc

 

[NORTON]

...If you don't have anything constructive to say keep your stupidity to yourself.

For the others, thanks for your input.

Ouch,,,
I thought buying a Bolt with 3 times the battery size and 3 times the range was a brilliant idea!

If you were able to get some SW that plays nice with a parallel pack in the back of the car and spent how much time and money
mounting and connecting the required coolant lines, HV and comm wires and doing something to the front and rear suspensions.....
How much money would you have tied up in this silly 2 seater?

You could sell the Spark and buy a Bolt and be on the road with a Gen 2 Long Range EV in a few days!!! Brilliant!!

And for a lot less dollars. Have you seen what you can buy a Bolt for?

 

[Infinion]

...If you don't have anything constructive to say keep your stupidity to yourself.

For the others, thanks for your input.

Ouch,,,
I thought buying a Bolt with 3 times the battery size and 3 times the range was a brilliant idea!

If you were able to get some SW that plays nice with a parallel pack in the back of the car and spent how much time and money
mounting and connecting the required coolant lines, HV and comm wires and doing something to the front and rear suspensions.....
How much money would you have tied up in this silly 2 seater?

You could sell the Spark and buy a Bolt and be on the road with a Gen 2 Long Range EV in a few days!!! Brilliant!!

And for a lot less dollars. Have you seen what you can buy a Bolt for?

Definitely, and while this does make sense if the goal is to get range in the easiest, least expensive way and for the greatest value, it is a different car. Some individuals desire to work on, upgrade, or modify their vehicles instead of trading them in for newer stock vehicles. Keep in mind people are still converting ICE vehicles to electric, so upgrading a spark EV is by no means unreasonable considering everything's all there.

It's not a secret that this kind of response -- bordering apathy -- has been shared before and spread throughout the spark EV forums. While rational, the suggestion does not address the topic and often intends to stifle the courage of those fishing for information who may be willing to spend the time and effort expanding their skillset. I'd love to see people doing more of that over trading stock vehicles.

Is it possible to install a second drive battery pack atop (and in parallel to) the resident battery pack of six to double the vehicles range?
And yes, I am okay without a back seat and hatch compartment. I can Not find any information about wire harness or connections to/from
the drive batteries. The info on these EVs is very sparse.

Thank you,
JT

Yes it is possible to parallel high voltage batteries. It, however, very much depends on how you want to do it, and to what extent. I would recommend first to buy yourself a service manual or get an online service manual subscription to view all the dealer level information on schematics, functional descriptions, removal and replacement procedures, and connector diagrams. The more you understand the existing drive motor battery management system, the better position you'll be in to make an informed decision for a Spark EV or any future electric vehicle upgrade for that matter.

If you are installing a battery pack carrier between the hatch and rear seats (atop the existing battery pack), you first need to ensure that the carrier is exceptionally secured to the frame. This goes without saying if you're going to use your own subfloor instead of a second carrier. In the case of an accident, you don't want to have up to 400 pounds of batteries shifting inside the vehicle and crush you from behind, and since the batteries are higher up, the only thing that would stop a battery carrier that sheared off from its fasteners are the front seats. The original drive motor battery, by contrast, is secured to the car from the underbody, securely fastened to the frame.

The next questions that needs to be investigated are how to interface the new/used spark EV battery pack, and this includes ensuring there is unobstructed access to the manual service disconnect (needs to be moved) along with the electrical connection to the 363V bus bars, and if the Battery Energy Control Module has the ability to add more cell groups / modules to its OEM BMS for balancing and communication. If the OEM BMS does not have spare connector pins to crimp for extra battery interface modules that can directly report to the powertrain control module 2, then you'll be looking at two sets of battery energy control modules, one master, and one slave that is really more of an isolated unit without communication with the master.

To get a better look at the battery and parts involved without vague stock images from press releases or gritty service manual drawings, I highly recommend spending some time on the Weber Auto youtube channel. The closest comparison to the Spark EV's battery pack and technology would be the Chevy Volt, and you can watch this video for a detailed real world view:
https://youtu.be/eWYtq0hxhQg.

There is also a comprehensive breakdown of the Bolt EV's battery, and all the high voltage components. It is an instrumental source of information.

For all of the connector names, electrical schematics, you can supplement info from the service manual, which will list the connector type, the pins and what they go to.

The Volt, the Spark EV, and the Bolt all have unique shapes, but the configurations are more or less the same. If you can fabricate a custom subfloor/carrier for the spark EV that efficiently packs it into the trunk/backseat area, I think that would be the most ideal, rather than the carrier that would most likely drape over the interior in an awkward way.

Another note on building confidence and inspiration for this kind of job is Rich Benoit (Rich Rebuilds) who recently "finished" his mini cooper conversion. Watch a few of these videos in the DIY budget electric mini cooper series to consider if you even want the OEM spark battery and carrier set (which is available new, used, or through auction), or if you want a different 96S pack from a different car (with coolant ports).

https://youtu.be/KBekVxvIe4s

You'll also need a place to work on your car. At certain points in the project, the car won't be drivable at the end of the day, so having a communal shop, your own garage, or a 300-900+ sqft industrial / storage space with bay doors for lease would be a good idea.

Lastly, look on google maps or by any other means, and research what businesses are in your area that can consult with you on a job like this, or take care of difficult portions of the project for you (like designing and fabricating the subfloor).

 

[NORTON]

...If you don't have anything constructive to say keep your stupidity to yourself.

For the others, thanks for your input.

Definitely, and while this does make sense if the goal is to get range in the easiest, least expensive way and for the greatest value, it is a different car.
Some individuals desire to work on, upgrade, or modify their vehicles instead of trading them in for newer stock vehicles.....
While rational, the suggestion does not address the topic and often intends to stifle the courage of those fishing for information who may be willing to spend the time and effort expanding their skillset.
I'd love to see people doing more of that over trading stock vehicles.

Is it possible to install a second drive battery pack atop (and in parallel to) the resident battery pack of six to double the vehicles range?

Yes it is possible to parallel high voltage batteries....

You, sir, have done your research!
Except, NO you can't just "parallel HV batteries". HV batteries are always setup in a series. Typically most are ~400VDC.
The cells need routine balancing which is provided by the BMS. This pack has TMS provided by a coolant heater and the AC compressor through a heat exchanger in the HV battery coolant loop.
There is no way to individually monitor both packs separately when they are paralleled.
Let's talk about the SW required to run such a set up. Where is that coming from?
The SW is locked away.

This is not RC electric cars where if you damage a pack, you buy a new one and press on.
I intend to 'stifle' this course of 'doubling the range of a $6k EV.
Especially when you can buy an EV with 3 times the range for ~$13k.
And it remains a 5 seater, not a dangerous 2 seater. We did mention suspension upgrades needed, no?

Now, if this young gun want to transplant the Drive Unit and Batter Pack and all the other components needed to make them play together, including the SW, and put it into a lightweight 3 wheeler sports car, I'm with him all the way!!!
How much faster would this thing be? !!

Look at the TriHawk! Car&Driver tested one and loved it. They said it was a Lotus 7 with front wheel drive. You couldn't tell it was a 3 wheeler unless the rear wheel hit a bump the fronts missed.
Look at this design and tell me that it's not perfect for the Spark EV drive unit and pack!!
Helll you could use the front struts and suspension components and use half of the rear trailing link and strut in the back!
The nose wouldn't need to be this long because the Spark EV has the drive unit mounted transverse.
The Trihawk used a longitudinal mounted engine and transaxle.

Sorry, I don't have the skillset to place an image into the body of this post....
https://www.ecosia.org/images/?q=trihawk 304#id=3C17D676A0DCE68191D46D2BEDA773CF29D65FC6

https://barnfinds.com/wild-three-wheeler-1984-trihawk-304/

https://trihawk304.com/history/

 

[Infinion]

You, sir, have done your research!
Except, NO you can't just "parallel HV batteries". HV batteries are always setup in a series. Typically most are ~400VDC.

Regarding series and parallel, I gave the original poster the benefit of the doubt that they either understand what this means, or will pick up the cell configurations along the way, particularly in the key resources I point to. But if we're going into semantics here, I will rebuttal that there is no such thing as a 400V high voltage battery, rather there are cell groups and modules that add 3.7V cells up in series groups of 16 per module (for the Spark EV) to reach 363V nominal after the module sections are series connected. I mentioned this. but could it be that you didn't read my entire post?

I don't want to get too off topic here, but I wanted to point out, NORTON, that you have played devil's advocate more than a few times on topics in the Spark EV forum, both in General, as well as here in the Technical Spark EV forum's subcategories regarding questions about changes or modifications to the hybrid drive systems. I mentioned it before, but suggesting to someone to buy a new car, while potentially a good idea, does nothing to address their questions, especially when they choose to post it in the technical subcategory of the forum, where the minimum expectation is to answer the question and not give car buying advice. I believe the issue was mostly the counterproductive sarcasm offered.


You've generated a lot of good content on the forum and have kept activity healthy, but please don't spread apathy. People have worked on cars for a long time, and while you could say the level of skill is changing and broadening, so too is the access to knowledge bases online.

This is not RC electric cars where if you damage a pack, you buy a new one and press on.
I intend to 'stifle' this course of 'doubling the range of a $6k EV.
Especially when you can buy an EV with 3 times the range for ~$13k.
And it remains a 5 seater, not a dangerous 2 seater. We did mention suspension upgrades needed, no?

What's with the hypotheticals? There are no damaged packs or dangerous 2-seaters? This is the kind of attitude I'm talking about. The due diligence is on the individual to properly secure their batteries down, seek professional advice, etc. It always has been at their own risk and discretion. That includes everything along the way, including suspension. Reserve your judgement for when those individuals take blind risks without said due diligence.

The cells need routine balancing which is provided by the BMS. This pack has TMS provided by a coolant heater and the AC compressor through a heat exchanger in the HV battery coolant loop.
There is no way to individually monitor both packs separately when they are paralleled.
Let's talk about the SW required to run such a set up. Where is that coming from?
The SW is locked away.

All of the BMS tasks such as balancing and cell monitoring take place on the Battery Energy Control Module (BECM) between it and the battery interface control module on the battery packs. I mentioned this in my post. There are very few situations where skipping the BMS makes sense, so I'm glad to see you agreeing here.

There is no way to individually monitor both packs separately when they are paralleled.

This is untrue. While it's very likely that a single BECM does not have the built-in hardware to connect to and manage multiple battery packs (battery interface modules), and you would have limited means to connect more. However, with the addition of another BECM, all cell-level information can be accessed by the serial interface on the BECM with the use of a 3rd party CANbus dongle. From there you can do whatever you want. Set up two units to communicate wirelessly and send commands directly to the host controller – the powertrain control module 2 – to control any component in the car given conditional statements based on the cell information. That would include increasing heater/compressor/pump power if cells in the additional pack need to be regulated.

Look at the TriHawk! Car&Driver tested one and loved it. They said it was a Lotus 7 with front wheel drive. You couldn't tell it was a 3 wheeler unless the rear wheel hit a bump the fronts missed.
Look at this design and tell me that it's not perfect for the Spark EV drive unit and pack!!
Helll you could use the front struts and suspension components and use half of the rear trailing link and strut in the back!
The nose wouldn't need to be this long because the Spark EV has the drive unit mounted transverse.
The Trihawk used a longitudinal mounted engine and transaxle.

It sounds like you've marked the car for your next EV conversion! Should be very fast with its 650kg curb weight. Perhaps with 0.7g-0.8g peak acceleration.

Sorry, I don't have the skillset to place an image into the body of this post....
https://www.ecosia.org/images/?q=trihaw ... CF29D65FC6

https://barnfinds.com/wild-three-wheele ... ihawk-304/

https://trihawk304.com/history/

You do, as you have in previous posts...

 

[NORTON]

1... I will rebuttal that there is no such thing as a 400V high voltage battery,.. (for the Spark EV) to reach 363V nominal...
2. I don't want to get too off topic here, but I wanted to point out, NORTON, that you have played devil's advocate ... regarding questions about changes or modifications to the hybrid drive systems.....
..., but please don't spread apathy. .....
3. ...[Bolt v Spark EV with an extra 600lb battery pack, packed in somewhere...]
And it remains a 5 seater, not a dangerous 2 seater. ...
4. ... This is the kind of attitude I'm talking about....Reserve your judgement for when those individuals take blind risks without said due diligence.
5..., all cell-level information can be accessed by the serial interface on the BECM with the use of a 3rd party CANbus dongle. ....
6. It sounds like you've marked the car for your next EV conversion! Should be very fast with its 650kg curb weight. Perhaps with 0.7g-0.8g peak acceleration.

1. Right. I just used 400VDC as an example. That's what DCFC stations are nominally rated. (Some are now 800VDC also.)
2. Guilty as charged. I rain on parades.... Why modify the EV drive system? (not hybrid in this case). SW could be hacked, but why? It works great stock. Now put it in a car weighing 1/3rd!
3. So where does this 600lb 2nd battery pack go? Ty-rapped in the passenger compartment?
The stock Spark was already beefed up to become the heavier Spark EV.
It is a somewhat safe, cheap, Korean S-Box of an econo car with all the air bags. Why modify a crappy little Sbox? Why throw a dime at it?
4. Guilty.
5. Sure, the second pack could be talked to and managed on it's own. But what about the Big Switch that changes the car from original to this secondary pack,,,, (strapped down somewhere in the back?)
6.That's right! Did you see the article from way back then where the Trihawk pulled more Lateral G's than a current (for the time) Lamborghini?

I guess when my great, great, grandaddy said to me "Dammit Norton, why can't you leave well enough alone?", I finally am taking his advice.
But,,, put the Spark EV components in a light weight 3 wheeler using as much of the stock systems as possible, Well,,,,
You have the potential for a wicked fast fun machine!!
I'd even leave the ABS/traction/stability controls all working. That could be accomplished by putting both rear wheel speed sensors on the one rear wheel.
Kids, we all know what tire smoke looks like, right? Did you know you are faster without it? :shock:

Good catch on my temporary mod while I was giving my stock 12V battery a proper Capacity Check at work. Load tests don't tell the whole story.
I safely strapped in a lighter 12V battery.

Again, instead of modifying this already modified Gasser Spark, (The Spark EV), go test drive a cheap purpose built 2nd Gen EV, The Bolt. 3 times the range, just a few bucks more.
And then put your energy into a fast purpose built 3 wheel EV! It would be licensed as a motorcycle, making it easier to get road legal!