LG Chem Batteries from Battery Hookup. 5.94 KWh

t3kn0f1l3

New Member
I had a few reasons for my clamp design. My biggest concern was I didn't want to disturb the factory weld. I expect that it is fully able to conduct the power from the 3 cells to that buss bar as is. But if I drilled through those welds, I was not sure how much of the connection I would mess up. . . .
Thanks v. much GXMnow. Once again, your description is extremely helpful, esp. the details about separate application of dielectric grease on freshly-sanded copper and Noalox on aluminum-copper connections-also the clamping and torque specs. Your concern about the welded tabs is close to mine. Thinking about it - as I'm typing - makes me wonder if I might test by drilling through the weld on one of the blocks of cells that I have left over after my module surgeries. If I end up messing up that factory weld, I'll use your design for the modules. On the other hand, if I can get a clean hole on this test, I might play around with clamping the copper plate to the tabs only using screws, nuts, and washers. My thinking is that if I could go this route, I might use silicon-bronze fasteners, reducing (still not eliminating) the number of newly-introduced aluminum-copper contacts. I'm aiming to have 14 tabs on ea. module (to make a 14s9p bank), so the chances I could miss a potential loosening connection are higher. I'll plan to update here if I find anything noteworthy after I have the chance to do some test drilling. Does this silicon-bronze fastener option sound reasonable, or have I got to the point where I am I over-thinking this detail?
 
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GXMnow

Photon Sorcerer
The other concern I had was trying to drill in there without shorting to the next cell buss bar. There is just not much room for drilling at a 90 degree angle. Even tightening my clamp in there, I covered up the next adjacent buss bars with a few layers of tape so my screw driver and box end wrench had some protection. My old Makita drill does have the plastic knob around the chuck to tighten it, but to get a decent angle, I would need to use a long bit because the chuck is so fat.

Brass screws might reduce the chance of corrosion a little, but you also need to take into account they won't be near as strong as a stainless steel screw, so your clamp load will be less. Not sure how much difference that will make, but it is something to keep in mind. Ideally, all of the current should flow from the existing copper plated buss bar ro the new copper you are clamping against it. The screws should not be a current path.
 

Mart Hale

Solar Enthusiast
Yeah, I only drilled at a 45 deg angle and I did it slow and stead as having a drill bit going across those connectors was not an option for me :oops:.
 

Mart Hale

Solar Enthusiast
I am trying to figure out what is the max amps my batteries can be charged at ?????

Contains 30 LG Chem N2.1 60ah cells

The configuration is 10s, so it has 3 60AH cells in parallel.

So each cell group is 180 ah.

Is there a data sheet on LG Chem N2.1 60ah cells? looking..
 

GXMnow

Photon Sorcerer
Yes, you are reading that right. With my 6P setup, I could charge at up to 360 amps, and discharge at up to 1,080 amps. That is way beyond anything I will ever be able to do with my inverter. In our use, these cells will be coasting.
 

GXMnow

Photon Sorcerer
In the Chevy Bolt, the total pack is 96S 3P and it can crank out 200 HP to the front tires. At 100% efficiency, 1 HP is 746 watts. 746 x 200 = 149,200 watts. We can round that to 150 KW. (150,000/3)/96 = 520 watts out of each single cell. @ 3.7 volts, that is 140 amps. That is running a 2.33C rate or higher to make the performance that Chevy publishes. EV batteries are crazy powerful. Even though the normal charging is much slower, the regen brakes can stuff energy back in to the batteries at 70 KW. That is close to 1C.
 

Mart Hale

Solar Enthusiast
In the Chevy Bolt, the total pack is 96S 3P and it can crank out 200 HP to the front tires. At 100% efficiency, 1 HP is 746 watts. 746 x 200 = 149,200 watts. We can round that to 150 KW. (150,000/3)/96 = 520 watts out of each single cell. @ 3.7 volts, that is 140 amps. That is running a 2.33C rate or higher to make the performance that Chevy publishes. EV batteries are crazy powerful. Even though the normal charging is much slower, the regen brakes can stuff energy back in to the batteries at 70 KW. That is close to 1C.


Yes we are using a semi as a pickup truck. Being loaded this light it should last, and last and last....
 

GXMnow

Photon Sorcerer
The only real issue is the cycling. Even at light current, and not going to full to empty, NMC cells are not the best for many many cycles. In an electric car, they don't recommend charging back up every day. But you do have to wonder with regen events and such, we should still get more life. I hope for 5 or 6 years, if I get 10 I will be crazy happy. If something great comes along sooner, I might upgrade. But for the price of these, I couldn't pass it up.
 

Mart Hale

Solar Enthusiast
Yes. the price and being brand new is what forced me forward, I took a gamble and now I have solar powered AC. I have shut off the main power to my home, turning on only to run my dryer. I am seriously thinking of shutting off the mains, and using a generator to power my clothes dryer, Then put that 30$ a month electric bill toward the next battery system. In 5 years that would be 1,800$ With new tech that should be a whopper of a new battery. Going from 5 KWH to 23 KWH has been life changing for me. I want to take the money I am saving and apply it toward the next system.
 
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