Power bike with 3, 12V emergency car start packs?

I've seen these 12 Volt emergency car start lithium batteries that claim 20,000mah. Can we series three of them to power a 36 Volt E-trike? The price is close to that of a battery from China but NO shipping (which is about the same as the battery)! Anyone here from Tucson, Az.? Thanks. Larry Copas

Sure you can, ihas been done before,and there is a thread on here somewhere about it.
But do not believe all the stated ratings on those packs ,..their capacity is often way short of what they claim.
IE... “12V 2000Amp 368000mAh Jump Starter Box”
https://www.crazysales.com.au/online-12v-2000amp-368000mah-jump-starter-box-battery-pack-power-bank-for-car-207415.html?aid=11&gclid=EAIaIQobChMI0b6T2Kuj6gIVBQ4rCh3q6AJxEAQYAiABEgKF9vD_BwE
[youtube]y6MAb-vjwpU[/youtube]

Hillhater said:

Sure you can, ihas been done before,and there is a thread on here somewhere about it.

Click to expand...

for Larry: that would be Boyntonstu's topic:

Walmart Booster Batteries
https://endless-sphere.com/forums/viewtopic.php?f=14&t=74610

lbcopas@yahoo.com said:

I've seen these 12 Volt emergency car start lithium batteries that claim 20,000mah. Can we series three of them to power a 36 Volt E-trike? The price is close to that of a battery from China but NO shipping (which is about the same as the battery)!

Click to expand...

When manufacturers of packs like that claim a certain mAh capacity, they tally up the total of all the cells in the pack. That would make sense if the cells were in parallel, but they're not. Usually those boost packs are 3 cells in series (11.1V nominal, 12.6V fully charged). That means what they're really claiming is 20Ah/3, or 6.67Ah. Whether that is itself an exaggeration is anybody's guess, but... probably.

If you do what you propose, understand that what you'll actually be getting is a nominally 33V battery with six and a half amp-hours of capacity. Which may or may not be an accurate representation.

I think you'll have better luck buying a Glorious Fortune™ mystery pack from eBay, unless what you have in mind requires high amps.

Balmorhea said:

When manufacturers of packs like that claim a certain mAh capacity, they tally up the total of all the cells in the pack. ......

Click to expand...

Hmmm, ? ...i would like to see how that works for those “368,000mAh” packs that i linked to ..! :lol:
Mostly, i suspect they just make up numbers and lie !

Hillhater said:

Balmorhea said:

When manufacturers of packs like that claim a certain mAh capacity, they tally up the total of all the cells in the pack. ......

Click to expand...

Hmmm, ? ...i would like to see how that works for those “368,000mAh” packs that i linked to ..! :lol:
Mostly, i suspect they just make up numbers and lie !

Click to expand...

There is that, too. But for power banks and booster packs, the (misleading) custom is to series up X number of Y amp-hour cells, and claim X*Y amp-hours.

Did not read all posts.

Those packs "mAh" capacity is rated at the per-cell voltage, very deceptive.

Open one up and you see the same cell types we use, just marked up like crazy.

The ones that put out 19V for laptops etc **could** maybe be stacked

but really would not make sense to do so, even if you got a container load for free better off just stripping them for cells.

RC LiPo would give much better bang for buck.

ex EV packs even more so.

Some of the jump starter packs do use high C rate lipo pouch cells.