2012 Chevy Volt Battery:

BogdanT said:

Is it just me or you shouldn't parallel between modules for your setup. You will destroy the 6s as it's only 22.5V, others are 45V

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Are you confusing parallel and series?

• The 6s modules are in parallel only with each other, so they see the same voltage and there is no problem.
• Of course the 6s modules are in series with 12 s modules, but all modules have the same capacity (all cells identical and 3 parallel cells in every module) so the fact that they pass the same current is appropriate.

Mandres said:

Would it be ok to run these modules mounted upside down (with the terminals pointed towards the ground)?

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An extreme example of packing Volt modules into a car is the work mfor100 has done in his 911 RSR with Tesla Motor...; the module mounting arrangements for front and rear are shown in post #51 and post #80.

Mandres said:

Do pouch cells care which way they're mounted?

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I can't think of any reason why orientation would matter to the cells. Structure and cooling arrangements for the modules might be more of a concern, although that 911 shows that that they don't need to be upright.

WattsUpDoc said:

I've been trying to find the motor constant (Kv) and resistance specs on the Netgain motor that would let me model maximum speed vs pack voltage under varying load, but haven't come across them. Trying to estimate that from their power performance charts, I see them running up to 7200RPM on a 120V supply, but torque starts dropping at about 2200RPM, and peak power is at 3600 RPM. So I can see that being an issue with the low pack voltage - I'll need to do some more math...

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The Netgain performance charts are... "interesting". It appears that they spin the motor up without load, then progressively apply resistance with a brake setup to measure torque, and quit when it stalls. I think this would be a good high school science project, but is laughable for a 21st century motor supplier. They have no data below the peak torque point, but presumably if you maintain current below that speed you'll get roughly constant torque.

WattsUpDoc said:

I've been trying to find the motor constant (Kv) and resistance specs on the Netgain motor that would let me model maximum speed vs pack voltage under varying load, but haven't come across them. Trying to estimate that from their power performance charts, I see them running up to 7200RPM on a 120V supply, but torque starts dropping at about 2200RPM, and peak power is at 3600 RPM.

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brian_ said:

The Netgain performance charts are... "interesting"...

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I was assuming that you were referring to Netgain's usual series-wound brushed DC motors, for which this is the only performance data provided.

WattsUpDoc said:

I'm actually looking at the Hyper9 SRIPM motors.

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That motor is another matter entirely. Netgain publishes more useful performance data, which is provided by the motor's manufacturer. But that's a subject for that other thread...

joekitch said:

so one full pack is like ~400 pounds..?

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The complete pack (with housing) weighs

• first generation: 196 kg (432 lb)
• second generation: 183 kg (403 lb)

VOLT_BATTERY.pdf

streber said:

They are a 3/4" ORB fitting.
...
Standard 3/4" pipe will screw in, but won't seal without a ton of tape. It really wants the o-ring to seal.

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Pipe threads seal on the thread itself - the thread is tapered so that the fit gets tighter as the parts move together with fitting rotation. O-Ring Boss (ORB) fittings seal with an o-ring outside of the straight threads between the boss around the female port and a matching face on the male fitting, and the threads are just to mechanically hold it together. Please don't ever try to fit any tapered thread into or around any straight thread, and don't try to seal the threads of anything other than a pipe thread fitting.

swoozle said:

Whether or not they are supposed to work, I'm using nylon US garden hose thread (3⁄4-11.5NH ) to hose barb fittings on those threads and they have performed without leaking for more than a year now.

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Sure - it's a low pressure system. You can probably jam a hose in and wrap it with duct tape, and that would work, too. I wouldn't suggest that...

swoozle said:

I have to apologize. I was reviewing my setup and realized that I forgot a key part: I did use the o-ring from the original fittings. The nylon thread/barb fitting (Lowe's stock) had a nice shoulder on it that captures the o-ring well enough with the removal of a thread or two (dremel tool). The thermostat/heater housing that the fitting threads into has a recess for the o-ring.

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That's interesting... so it works basically as intended, but limited in engagement force and fit by the thread taper mismatch. Probably just fine for the low pressure.

brian_ said:

That's interesting... so it works basically as intended, but limited in engagement force and fit by the thread taper mismatch. Probably just fine for the low pressure.

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swoozle said:

Hmm? Neither of the threads is tapered.

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Sorry! I had typical plumbing threads in mind and was thinking of NPT, even though this was clearly about the "garden hose" thread. Of course that's not tapered (it seals with a gasket against the end of the male fitting, like a crude version of an ORF fitting) and there's no issue here.

Duncan said:

I have just opened up a Volt battery I bought - it took 8 months to get here
Its got 3 off 3.1 kWh modules and 4 off 2.3 kWh modules - so is that a Mk2 Volt?

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Yes, the Volt battery with 7 modules is the second generation (2016+). There are four 12S2P (45 V nominal and 24 cell each, so 48S and 96 cells total) and three 16S2P (60 V nominal and 32 cell each, so another 48S and 96 cells total).

https://media.gm.com/content/dam/Media/microsites/product/Volt_2016/doc/VOLT_BATTERY.pdf

Duncan said:

Does that use the same chemistry as the Mk1?? - the cells are at 3.37 volts to 3.39 volts -

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Both generations are described by GM as "NMC-LMO". Cell voltage ranges should be very similar between generations.

piotrsko said:

All I know is on a mk2 the pouches are the same but wired different. Might be a cooling plate.

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The Mk2 or second generation modules are similar (including the same internal cooling fin design), but the Mk 2 cells have substantially higher capacity, apparently resulting largely from being thicker - Mk1 is 96S3P and Mk2 is 962P, so there are only 2/3rds as many cells in the Mk2, but with higher total capacity.