# Electric GT OX drive batteries



## Tremelune (Dec 8, 2009)

The company that made the V8-style motor stack has released a battery pack that offers voltage/Ah customization and numerous sizes in the shoebox-or-two range:









OX Drive Batteries - Electric GT - Electric Vehicle Systems


OX-Drive Battery modules represent the core energy source behind EV Systems from Electric GT. OX Drive Batteries are an ideal energy source for automotive aftermarkets, electric vehicles, and energy storage systems. OX Drive Power & Energy Modules offer a robust variety of applications.




electricgt.com





Extensive specs:



https://electricgt.com/wp-content/uploads/2020/09/ox-drive-battery-brochure.pdf



Prices are $270-320/kWh depending on size and configuration. Figure maybe $200-300/kWh for a salvaged Model S battery (the low price involving the purchase of the entire pack), this might be a compelling option. A salvaged Leaf pack is still the bang-for-buck champ at around $150-200/kWh, but Model S batteries are better in every way besides packaging. Weight is like 80-90Wh/lb (Model S is closer to 100Wh/lb).


----------



## ishiwgao (May 5, 2011)

I'm curious what cells they are using to offer "Battery density is comparable to the Tesla 5.3kWh Module... Modules are are (sic) rated at 2,000 cycles to 85% capacity". 

even at $320/kWh, it's offering both high density and high durability. sounds a little too good to be true...?


----------



## buseybr (Nov 25, 2019)

Tremelune said:


> The company that made the V8-style motor stack has released a battery pack that offers voltage/Ah customization and numerous sizes in the shoebox-or-two range:
> 
> 
> 
> ...


Just ordered the OX Drive Power. They are going to customize for my Sandrail Hyper9 Project. Blew out my LGChems which left me choosing between Teslas and OXDP. OXDP were customizable, cheaper, and would fit my project better. Standby for updates. 8 weeks is the lead time.


----------



## ishiwgao (May 5, 2011)

buseybr said:


> Just ordered the OX Drive Power. They are going to customize for my Sandrail Hyper9 Project. Blew out my LGChems which left me choosing between Teslas and OXDP. OXDP were customizable, cheaper, and would fit my project better. Standby for updates. 8 weeks is the lead time.


looking forward to hear from you how it performs


----------



## Roadstercycle (Jun 26, 2019)

I am also very curious as to the outcome of your order. Also, I'd like to know what you meant by "Blew out my LGchems"


----------



## remy_martian (Feb 4, 2019)

Looks like it's merely a series stack of Chevy Bolt batteries with milled end plates. 

What else is there?

What's the cooling strategy?


----------



## McGeesCustomMinis (Oct 26, 2020)

remy_martian said:


> What's the cooling strategy?


For some reason I thought they were air-cooled originally, but offers this in the brochure:

BATTERY THERMAL MANAGEMENT SYSTEM (TMS) Electric GT offers a fully integrated TMS Suite of Products to address proper Battery Thermal Management. Both core Products and Systems are available to support the EV industry. Battery Chill Plates, Thermal Pads, and Coolant Systems are available through Electric GT


----------



## brian_ (Feb 7, 2017)

They appear to have thermally conductive plates between cells which bend 90 degrees at one long cell edge (or both opposite long cell edges) to form a heat transfer surface on one (or two opposite faces), where a "chill plate" (heat exchanger) is to be placed. This is the usual LG Chem design, found in the modules used in the Chrysler Pacifica, Chevrolet Bolt, and others.

The "Energy" modules (left in the photo, plastic cover on top and cast aluminum housing on the end) appear to be set up for heat transfer on the bottom only, while the "Power" modules (right in the photo, milled aluminum housing on the end) appear to be set up for heat transfer on both sides, and one short cell side as well. The drawing for the power modules says 
"Chill plate can be mounted to Either side or Bottom(less surface area)"


----------



## brian_ (Feb 7, 2017)

I thought that the Energy modules looked a lot like what Zero EV sells as Calb 3P4S Battery Module 2.2 kWh. I finally got around to checking dimensions, and they're identical. My guess is that ElectricGT is buying the same 4S3P and 6S2P modules from *CALB* as Zero EV, and selling them as "OX-Drive Energy".
That's okay, as long as these are new modules, legitimately purchased, and ElectricGT stands behind the warranty (whatever it might be). From any supplier, the 6S choice is great for those wanting to build a moderate size of pack: for example,16 modules for 42.6 kWh at 360 V nominal from 249 kg, instead of 24 of the same size modules with the 4S configuration or only six of the formerly ubiquitous LG Chem 16S1P modules with only 16 kWh of capacity. For buyers outside of the UK, I'll note that ElectricGT's price is much lower ($599 USD) than Zero EV's (£570 GBP).

Among other implications, this means that the OX-Drive Energy modules would fit Zero EV's *cooling plates* (and pads and mounting hardware). Unfortunately for those of us in North America, those plates use British Standard Parallel Pipe ports (which are not compatible with NPS); at least it's a face-sealed joint, rather than tapered thread seal.

One caution in reading the OX-Drive specifications: ElectricGT is listing the *number of cells* in series as just "cells", and listing amp-hour capacities for the module, rather than the cell. The Energy modules are listed as roughly 100 and 150 Ah and implied to be 6S1P and 4S1P, while they appear to be actually composed of 6S2P and 4S3P configurations all of the same roughly 50 Ah cells. Again, I don't see anything wrong with the design - the documentation is just not clear.


----------



## ishiwgao (May 5, 2011)

brian_ said:


> I thought that the Energy modules looked a lot like what Zero EV sells as Calb 3P4S Battery Module 2.2 kWh. I finally got around to checking dimensions, and they're identical. My guess is that ElectricGT is buying the same 4S3P and 6S2P modules from *CALB* as Zero EV, and selling them as "OX-Drive Energy".


The identical dimensions may not be coincidence, and both modules may or may not be identical components.

I say this because most modules from battery manufacturers in China are built to follow the VDA standardization (from Germany), which comes in the 355, 390 or 590 standard. Numbers represent the length in mm, but the width and heights are fixed according to each modules too.

Likewise, many automakers in China and around the world are also using this standard size to maximize cost savings from off-the-shelf parts. e.g. VW's MEB platform uses the 590 standard, while NIO for example uses the 355. 

The CALB 3P4S cells from Zero EV is 355mm, and OX-Drive is 356mm. They may be identical components, or they may just be following the same standard.


----------



## brian_ (Feb 7, 2017)

ishiwgao said:


> ... most modules from battery manufacturers in China are built to follow the VDA standardization (from Germany), which comes in the 355, 390 or 590 standard. Numbers represent the length in mm, but the width and heights are fixed according to each modules too.
> 
> Likewise, many automakers in China and around the world are also using this standard size to maximize cost savings from off-the-shelf parts. e.g. VW's MEB platform uses the 590 standard, while NIO for example uses the 355.


Excellent info  Leave it to the Germans to actually make a standard, in an industry segment which has so far been highly resistant to standards.



ishiwgao said:


> The CALB 3P4S cells from Zero EV is 355mm, and OX-Drive is 356mm. They may be identical components, or they may just be following the same standard.


The energy capacity, number of cells, and the two offered configurations (4S3P or 6S2P, but not 12S1P or 3S4P or 2S1P) also match, and the externally visible construction and terminal configuration are nearly identical... but that could be just be that both manufacturers (CALB and the mystery source of the OX-Drive Energy) made the same sensible choices, perhaps even with the same cells, and the terminals might be part of the standard.


If standards for battery modules become widespread (not just used by some German manufacturers), choosing modules which conform to the standards might be valuable when the time for replacements comes in the future.


----------



## Roadstercycle (Jun 26, 2019)

brian_ said:


> I thought that the Energy modules looked a lot like what Zero EV sells as Calb 3P4S Battery Module 2.2 kWh. I finally got around to checking dimensions, and they're identical. My guess is that ElectricGT is buying the same 4S3P and 6S2P modules from *CALB* as Zero EV, and selling them as "OX-Drive Energy".
> That's okay, as long as these are new modules, legitimately purchased, and ElectricGT stands behind the warranty (whatever it might be). From any supplier, the 6S choice is great for those wanting to build a moderate size of pack: for example,16 modules for 42.6 kWh at 360 V nominal from 249 kg, instead of 24 of the same size modules with the 4S configuration or only six of the formerly ubiquitous LG Chem 16S1P modules with only 16 kWh of capacity. For buyers outside of the UK, I'll note that ElectricGT's price is much lower ($599 USD) than Zero EV's (£570 GBP).
> 
> Among other implications, this means that the OX-Drive Energy modules would fit Zero EV's *cooling plates* (and pads and mounting hardware). Unfortunately for those of us in North America, those plates use British Standard Parallel Pipe ports (which are not compatible with NPS); at least it's a face-sealed joint, rather than tapered thread seal.
> ...


Unfortunately the LG Chem 16s batteries have a cease and desist order for anyone trying to sell them. I have 12 and would like 6 more to give me a 48 kWh pack. Back to the drawing board for my next builds.


----------



## brian_ (Feb 7, 2017)

ishiwgao said:


> ... VDA standardization (from Germany), which comes in the 355, 390 or 590 standard. Numbers represent the length in mm, but the width and heights are fixed according to each modules too.
> 
> Likewise, many automakers in China and around the world are also using this standard size to maximize cost savings from off-the-shelf parts. e.g. VW's MEB platform uses the 590 standard, while NIO for example uses the 355.


The second generation of VW e-Golf (2017+) appears to use a VDA standard overall size as well; it is not MEB, and appears to use the VDA 355 standard overall size.


----------



## brian_ (Feb 7, 2017)

Roadstercycle said:


> Unfortunately the LG Chem 16s batteries have a cease and desist order for anyone trying to sell them. I have 12 and would like 6 more to give me a 48 kWh pack. Back to the drawing board for my next builds.


There is a fix for this situation: sell the 12 LG Chem 16S modules to people who want to assemble small packs, and build a 48 kWh pack for yourself from OX-Drive Energy modules.

18 LG Chem 16S modules: 2.7 kWh and 17.2 kg each, for 48.6 kWh and 310 kg in 211 litres of volume (presmably 3 or more strings of modules in parallel, for 360 volts or less)
24 OX-Drive Energy modules: 2.2 kWh and 11.2 kg each, for 52.8 kWh and 269 kg in 142 litres of volume (if 4S3P connecting all in series would give 360 volts)
Of course it would be expensive because you would be selling existing stock at a private sale price and buying new modules at retail: the retail value of the LG Chem 16S modules was about $735 USD, or $13,230 total (depending on supplier - that's the EV West price), and the OX-Drive Energy modules are $599 USD from ElectricGT, or $14,376 total.

The LG Chem 16S modules are not really suitable for large packs because of their 16S configuration - unless you're building an extremely high-voltage pack, you end up paralleling them and so increasing wiring and BMS cost. People do it, only because that's what's available in what Tremelune called a "shoebox or two" format. The 4S and 6S configurations of the OX-Drive (and CALB from Zero EV, and VW eGolf) modules allow all of the modules in the pack to be connected in series for reasonable pack sizes.


----------



## mdrobnak (Mar 19, 2020)

I always wondered if the EV West stock was 'new' or used cells. If new, $735 wasn't bad. But I paid $450 from Thunderstruck Motors for used cells. I've yet to get them into a vehicle, but you know how that goes...

-Matt


----------



## asymptonic (Oct 14, 2021)

Bumping an old thread. Curious if anyone ever did get their hands on one of the "power" series batteries to see how they worked out?


----------



## Roadstercycle (Jun 26, 2019)

I bought 16 of the power batteries. I have not driven a lot with them as I just finished the car they seem very powerful. I do love the size as I got 12 under the hood down low and 4 in the tunnel. 06 Mustang with M3 motor.


----------



## asymptonic (Oct 14, 2021)

Roadstercycle said:


> I bought 16 of the power batteries. I have not driven a lot with them as I just finished the car they seem very powerful. I do love the size as I got 12 under the hood down low and 4 in the tunnel. 06 Mustang with M3 motor.


Which sizes did you go with?


----------



## Roadstercycle (Jun 26, 2019)

2.66KWH 

----- Kwh , ---- modules, ---- cells, ---- Module ah, ---- volts/cell, ---- total volts, ---- peak amp, ---- lbs/kgs


----------



## brian_ (Feb 7, 2017)

Roadstercycle said:


> I bought 16 of the power batteries. I have not driven a lot with them as I just finished the car they seem very powerful. I do love the size as I got 12 under the hood down low and 4 in the tunnel. 06 Mustang with M3 motor.





asymptonic said:


> Which sizes did you go with?





Roadstercycle said:


> 2.66KWH
> 
> ----- Kwh , ---- modules, ---- cells, ---- Module ah, ---- volts/cell, ---- total volts, ---- peak amp, ---- lbs/kgs
> View attachment 126430


The modules are shown in the car in Roadstercycle's "part 4" YouTube video.




96 "cells" divided by 16 modules would be 6 cells per module, but despite what Electric GT publishes, these are clearly not 6-cell modules. They have 6 cell _groups_, each group consisting of smaller cells in parallel, so the modules are each:

6S so 22.2 V nominal,
2P with 60 Ah cells or 4P with 30 Ah cells; 120 Ah either way,
12 60 Ah cells or 24 30 Ah cells, 
2.66 kWh
The battery is then 192 cells of 60 Ah each in a 96S2P configuration or 384 cells of 30 Ah each in a 96S4P configuration (not 96S1P of 120 Ah cells).

This is type #4 in the module configuration index in the OX Drive battery brochure. The combination of 16 of them, shown in the snipped portion of the table in the post above, is one of the combinations in the table on page 7 of the brochure; I find it easier to read the headings from the full table in the brochure.

An electrically equivalent configuration could be built of

16 modules @ 6S each (module type #4, this project),
12 modules @ 8S each (module type #9), or
8 modules @ 12S each (module type #13)
... for the same pack voltage and energy, and about the same mass and volume, as suits packaging in the vehicle... but only #4 is a "standard" module - the others are "special order". It appears that all OX Drive Power modules have 12, 16, or 24 60 Ah cells, or 24 32, or 48 30 Ah cells, and only some of the possible combinations of series and parallel connections within those sizes are offered, even as special orders.


----------



## asymptonic (Oct 14, 2021)

Yeah, I was just looking over their tables and boggling at the wrong-math of their module/voltage calculations.


----------



## brian_ (Feb 7, 2017)

asymptonic said:


> Yeah, I was just looking over their tables and boggling at the wrong-math of their module/voltage calculations.


It's okay once you realize that they are using different electrical groupings of the same cells, and are listing the parallel cell group as if it is one cell of larger capacity.


----------



## asymptonic (Oct 14, 2021)

Yeah, I understood what they were going for, but it just didn't match my expectations. This line in particular irritated me. 20 modules at 22v nominal for a Hyper9 HV results in way over the allowed max voltage for the inverter without paralleling the modules:


----------



## brian_ (Feb 7, 2017)

asymptonic said:


> Yeah, I understood what they were going for, but it just didn't match my expectations. This line in particular irritated me. 20 modules at 22v nominal for a Hyper9 HV results in way over the allowed max voltage for the inverter without paralleling the modules:
> 
> View attachment 126443


That example combination is

71.0 kWh
20 modules
40 cells (actually cell groups) in series
480 Ah
22.2 V nominal module voltage
25.2 V maximum module voltage
148 V nominal pack voltage
168 V maximum pack voltage
940 lb or 428 kg
This is from the examples which are supposed to be using 3.55 kWh modules, with 71.0. kWh in 20 modules they are 3.55 kWh each. With 40S in 20 modules they are 2S modules, which do have 480 Ah capacity. That's the #11 module type:


> 11) OXDP 3.55kWh 7.4vdc 2s Spec Order


The module description specifies a suitable voltage (3.7 V/cell x 2 cells = 7.4 V), but the example has the wrong module voltage - presumably just a typo. 40S @ 3.7 V/cell or 20 modules in series @ 7.4 V/module is the right voltage (148 V nominal, 168 V peak), and that's suitable for HyPer 9HV.

The 56.8 kWh line for 16 of the 3.55 kWh 2S modules has the same module voltage error and there's at least one other line with a similar error.


----------



## asymptonic (Oct 14, 2021)

Yep, I feel like they had an intern put together a spreadsheet. Either way doesn't build a ton of confidence beyond the fact that there is clearly some decent fabrication engineering surrounding whatever their cell supply is. The 'Energy' modules are pretty obviously generic but they spent more time in their engineering and marketing on the 'power' modules. They are appealing for the more varied voltages available and varied sizes, but..


----------



## brian_ (Feb 7, 2017)

asymptonic said:


> Yep, I feel like they had an intern put together a spreadsheet. Either way doesn't build a ton of confidence...


I just imported their example configurations (for all three Power module sizes: 2.66, 3.55, and 5.3 kWh) to a spreadsheet and ran some checks: the only errors are that the module voltages for types 8 (3.55 kWh 16S) and 11 (3.55 kWh 2S) are incorrectly stated in the example table, in every instance of those modules - that's almost half of the 3.55 kWh examples. The other values (total pack voltage, Ah capacity, number of cells in series, and energy for the stated number of the appropriate module) are all correct (meaning consistent with module specs) even for these configurations.



asymptonic said:


> ... there is clearly some decent fabrication engineering surrounding whatever their cell supply is. The 'Energy' modules are pretty obviously generic but they spent more time in their engineering and marketing on the 'power' modules. They are appealing for the more varied voltages available and varied sizes, but..


I agree that it is a systematically assembled range of module options from a single cell size and corresponding set of module stack components.


----------



## brian_ (Feb 7, 2017)

In sorting through the example configurations, I noticed that they are all listed at no more than 1800 A peak current, although with the larger capacities (240 Ah and up, resulting from 8 or more of their 30 Ah cells in parallel) more than that would be expected for the cells; lower capacities are rated at 8C peak current. There must be an interconnection wiring or device limit at 1800 A. I assume that this is not an issue for the vast majority of builders.


----------



## serious_sam (Mar 1, 2017)

Thought I'd bump this thread to see how these OXDP packs were going for people who were using them.

Any real world data that you can share please ? Cycles, degradation, internal resistance, etc.

WRT DC resistance, the datasheet table (page 19of25) states 0.75mOhms for the 30Ah cell.

However, if you go by the "25degC continuous discharge" curves (page 20of25), the deltaV between 1C and 5C (120A) looks like about 0.3V, which calculates to 0.3V/120A = 2.5mOhms. That's over 3 times higher than the table data.

Disclaimer: I understand that taking the Vsag difference between 1C and 5C to give an equivalent [email protected] is not an exact science, but gives a ballpark for intents and purposes.

If anyone has any real world data on these cells, that would be awesome.

As a comparison, I run Sony VTC6 cells in my bike, and I get the same comparitive IR: 
25mOhm (3Ah VTC6) vs 2.5mOhm (30Ah OXDP).
(25mOhm is also what I calculated from the discharge curves in the the VTC6 datasheet, for a sanity check).

I run VTC6 cells at 10C (30A) for short durations (couple of minutes at a time maybe in an enclosed pack with no cooling). So the claim that OXDP can do 8C or 10C for short durations sounds totally plausible.

The energy and power density (both volumetric and weight) for those OXDP cells is also nearly identical to VTC6. At half the price of the VTC6, clearly easier to build a car sized power supply from, and much better (claimed) cycle life.


----------



## buseybr (Nov 25, 2019)

ishiwgao said:


> looking forward to hear from you how it performs


 They have performed wonderful. Sorry for the delay in responding, it has been a long few years with the pandemic in medicine.


----------



## buseybr (Nov 25, 2019)

ishiwgao said:


> looking forward to hear from you how it performs


They are amazing. I have no problems with the battery performance. Sorry for the delay. Long pandemic in medicine.


----------



## serious_sam (Mar 1, 2017)

buseybr said:


> They are amazing. I have no problems with the battery performance. Sorry for the delay. Long pandemic in medicine.


Thanks for the feedback.


----------



## serious_sam (Mar 1, 2017)

I just received a response to an enquiry i made with Electric GT, wrt purchasing some of their OXDP modules.

Unfortunately they do not sell them anymore, and only do full EV conversions now.

I asked if I could purchase raw cells, or if they could direct me to somewhere that does, and they said no.


----------

