2012 Nissan Leaf Battery Module 7.6V.
Patrick, Sun Jun 04 2017, 02:11AMI saw a long list of EV battery modules on Ebay in the midst of my EV car research, and thought whoa ! i could evaluate its internals and use it for my drones and other robotic projects.I think with a 3C output that means 100 Amps which does seem plausible when attempting to lift a drone. I just dont know how to cool it off.
The module in OEM form. Used 75 US$.
Some OEM module specs :
Case: Formed thin aluminum sheet metal.
Type: Pouch, 4 cells.
32.5 Ah and 3.75 V per cell.
Circuit: 2 series 2 parallel
7.6 volts nominal, 60 to 90 amp normal output.
Mass 3.787 kg (8.4 pounds)
Dimensions : 22.2cm W x 30.7cm L x 3.7cm H
Chemistry:
Cathode = LiMn2O4 with LiNiO2
Anode = Graphite
Striped down to the bare pouches.
Specs after liberation :
Mass 3.293 kg (7.3 pounds)
Dimensions (Cell Stack): 21.6cm W x 29.2cm L x 3.3cm H
Mass removed = 493 g (1.1 pounds)
14.6 % lighter.
Connecting bars : 0.252 cm^2 several centimeters long. Seemed to be harder to cut than natural copper. (Appx 3 or 4 awg.)
More pics:
Removed elements. The blue plastic layers are on top and bottom, hard to get them off but i did, they appear to be anti-abrasion material very slippery. These plastic film pouches are known to be delicate and prone to puncture, we drone pilots find this often.
Negative, Balance and Positive terminals.
2 series 2 parallel as manufactured.
Tabs all cut free. Soon to be arranged as 4 in series, 14.8 Volts. Ill be using copper strips from the hobby store of the same area as the original bus bar. The standard balance wires and connector will be added.
Junk removed from the battery. Some of this mass will be added back on in kapton insulating film and copper connection bar.
Im trying to calculate the differences compared to this
59.99 US$ for 5Ah versus 120 US$ for 32Ah , a 6.4 times difference is interesting.
Re: 2012 Nissan Leaf Battery Module 7.6V.
Carbon_Rod, Sun Jun 04 2017, 09:14AM
Most high drain rate batteries do not use parallel packs for several reasons.
1. The internal impedance will change with use, and will rarely be matched even if regularly balanced. Under heavy loads this can dissipate a significant amount of wasted capacity as additional heat (on rare occasion spontaneous fires).
2. Most air craft minimize cell count to match flight mode rpm with KV and prop pitch. Thus, a 3 cell or 4 cell setup is most common for VTOL to maximize flight time, as even a small LiPol can provide 20C to 50C.
3. The lower rpm of larger motors are not necessarily more efficient.
We found smaller dual isolated battery systems are better for performance due to the peak power output numbers (more surface area with negligible differences in power density), but flight times are still limited by the weakest cell in the packs.
ebay batteries are often production rejects or from users that dump packs showing the mentioned changes.
YMMV
Carbon_Rod, Sun Jun 04 2017, 09:14AM
Most high drain rate batteries do not use parallel packs for several reasons.
1. The internal impedance will change with use, and will rarely be matched even if regularly balanced. Under heavy loads this can dissipate a significant amount of wasted capacity as additional heat (on rare occasion spontaneous fires).
2. Most air craft minimize cell count to match flight mode rpm with KV and prop pitch. Thus, a 3 cell or 4 cell setup is most common for VTOL to maximize flight time, as even a small LiPol can provide 20C to 50C.
3. The lower rpm of larger motors are not necessarily more efficient.
We found smaller dual isolated battery systems are better for performance due to the peak power output numbers (more surface area with negligible differences in power density), but flight times are still limited by the weakest cell in the packs.
ebay batteries are often production rejects or from users that dump packs showing the mentioned changes.
YMMV
Re: 2012 Nissan Leaf Battery Module 7.6V.
Patrick, Sun Jun 04 2017, 11:38PM
Didn't want to buy new, and had to start somewhere.
Patrick, Sun Jun 04 2017, 11:38PM
Didn't want to buy new, and had to start somewhere.
Re: 2012 Nissan Leaf Battery Module 7.6V.
Patrick, Mon Jun 05 2017, 12:14AM
Im constantly struggling with this one, the U series of T-motors are 180$ and very low rpm - - 120 kv
Patrick, Mon Jun 05 2017, 12:14AM
Carbon_Rod wrote ...
3. The lower rpm of larger motors are not necessarily more efficient.
3. The lower rpm of larger motors are not necessarily more efficient.
Im constantly struggling with this one, the U series of T-motors are 180$ and very low rpm - - 120 kv
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