EZGO Elite / Samsung SDI for Techies
 

I am quite sure the Samsung SDI lithium battery pack in the EZGO Elite uses Samsung INR18650-29E7 cells in a 14s20p array (280 cells per pack). There are 2 of these packs (560 cells total) in an EZGO Elite 4.2 that TVGC sell.

INR18650-29E7 Datasheet...

https://telit.co.rs/PDFDokumenti/Li-...18650-29E7.pdf

Each cell weighs 45g x 560 cells for a total of 25,200 grams or about 56 pounds of lithium battery in 2 packs. For reference, one Trojan T875 lead-acid battery weighs 63 pounds...ONE!

56 pounds of INR18650-29E7 cells containing about 50 cents of SECO electricity will propel the EZGO Elite for 60 miles. Impressive.

560 INR18650-29E7 cells can be purchased in bulk for under 3 dollars each or about $1600.

Interesting - thanks!

Seeing more and more Elites everyday.
They're selling well.

For reference, a Yamaha Quietech requires about $4.50 of regular gas to traverse the 60 miles.
Over 60,000 miles, the electric EZGO Elite will save $4000 in fuel cost.
AND...About $2000 in just oil changes(40 changes X $50 a pop at TVGC)...IF you change the oil every 1200 miles as per owners manual.

As the batteries get older the range will get smaller. Cell phone batteries start losing their effectiveness within months. The $1600 bulk will not be the costs when the batteries go bad and they need to replaced.

Your math would mean the batteries can be recharged 1,000 times before needing to be replaced i doubt that. Cellphone batteries are lucky to last 500 charging cycles

The charge/discharge parameters on the EZGO application are all WELL within the 80% capacity/1000 charge cycles. Most likely it will be closer to 90% after 1000 cycles. The charge voltage is 4.05V per cell with very low charge (0.15C) and discharge current. Even the momentary max discharge current won't make the cells breathe hard (perhaps 0.5C). I don't know the cutoff voltage in the EZGO application but I suspect it is around 3.1V cell or 43.4V total battery pack voltage. However, the regen braking parameters are an unknown so don't know how that will effect longevity.

Cell phones trade battery cycle life for charge speed to max capacity. They want you to upgrade every few years. I doubt you will even get 500 cycles in a cell phone. If you charge at 5W to 90% max then you will probably double your cycle life.

The bulk price is just the bulk price.

Even Tesla cars are hitting 250,000 miles with less than 10% capacity loss. I doubt they were ever "Supercharged".
I think Tesla uses Panasonic cells.

Samsung SDI INR18650-29E7 18650 Lithium-ion Battery

I just changed 1 of these 3.7v in battery powered tire pump. 1 cell when bad, wasn’t very easy unsoldering and soldering new battery in. So if got 560 of these only way for individual to replace some would be get new cell pack. So, that bulk pack would have batteries cells connected, just replace the pack , I sure the pack can be reconditioned at company set up to do it if and when cell/cells go bad in pack and they will eventually go bad. Hopefully the cost in future will come done for lithium thus making packs more affordable.

I don't know how they are packaged or if they are even serviceable (I don't own an EZGO Elite...My neighbor let me use hers when she was away...FAR more than Im willing to spend) but they are not soldered...Soldering these cells is a big no-no. Wouldn't it be nice if the 280 cells were just socketed :)

In a tire pump application, they are not too concerned about battery cycle life. The pump tends to fail first. You got "lucky" :)
Or you let the battery discharge past its cutoff voltage too many times. Or let it sit fully charged for too many months.

FYI...I just got this pump for my golf cart/cars...Works great...don't know how durable it will be but I am sure the battery will outlast the pump...USB rechargeable. Auto pump shutoff and accurate.

Amazon.com

"If battery cell is soldered, this can cause leakage of cell or unpredictable defect due to thermal damage.
→ Soldering is PROHIBITED. Samsung SDI will NOT be liable for any defects caused by customer’s misuse of the battery cells (including soldering)."

All battery packs whether made up with 18650s or 21700s are spot welded in series (by machine).
No, a consumer should not attempt soldering.
A 18650 Li-Ion in thermal runaway is not something you want to experience.

A sign in our lab "Thermal runaway causes customer runaway"

Lithium-Polymer Battery Fire (Read Description) - YouTube

A really big downside of storing electrons in a chemical goo.

If someone would run their EZGO Elite until the low battery light comes on...wait an hour and take a battery pack voltage reading, that would be wonderful :)

Also, for those with Android devices, Android 12 added a parameter to their battery management section to only charge to 85% capacity to improve battery cycle life. Just turn off "fast charging" and toggle this "battery protection" for max battery life.

Now it is about $5.70 to go 60 miles in a gas cart...Still 50 cents for 60 miles in a EZGO Elite. I wonder when SECO electricity prices will rise.