New 1979 Vespa P200e Petrol to Electric Conversion

[minsk]

Every journey starts somewhere.
Herre is my 1979 200PE on her "lift".
This is my first electric build. I am doing a 3K QMS motor i got locally.
I am going to build a 20S 10P 72 volt battery.
I will be doing most of Scusi build.
He has been so helpful in answering all of my rookie questions.


More to come...

 

[MDG]

Hell yeah! Can’t wait to see the beautiful thing come to life! You’re running the same motor as him and everything?

 

[amberwolf]

That inboard fairing panel / "glove box door" is just begging to be replaced by this :

Communications Post

 

[SlowCo]

Nice project. Good luck and update often with lots of photos

 

[amberwolf]

I was really just kidding, but as soon as I saw that modded door panel it instantly reminded me of Space:1999's comm posts.

(makes me feel old that I saw at least some of that show during the original U.S. broadcasts as a kid)

 

[minsk]

Start of the new battery build. Still have to clean up the harvested 18650 batteries . Then they will be balanced . Not sure how many of them are good .

 

[harrisonpatm]

You've got a lot of different cells there. Confident enough the pack is going to deliver what you want it to?

 

[amberwolf]

"balance" only means the cells are all the same voltage when they are at some voltage point in the discharge/charge curve--usually when full voltage.

This does not mean they are the same characteristics or will perform equally.

If at minimum the paralelled cell groups are not the same characteristics (capacity and internal resistance) as each other, as groups (vs cells), the pack will not perform as well as it could, and often will not do what is desired/required in the system.

There's a bunch of threads around here about testing cells to match them up for use in a pack, in various ways...it's tedious, and can have significant test equipment costs depending on method, but usually gives a (much) better pack than just randomly choosing cells for the groups, especially with random recycled cells.

 

[harrisonpatm]

Where are you salvaging/harvesting these cells from?

 

[harrisonpatm]

laptop batteries

Laptop batteries are good for 1A discharge each, maybe 1.5a max. You said you're doing 10p. Even if you assume 2A discharge per cell (which is far too optimistic for the dozen different brands and characteristics that I see in your pic, but for argument's sake), 20a @ 72V = 1440W max discharge for your proposed pack of salvaged laptop battery cells. That's not going to be enough for the weight and speed you're looking at.

i may go with jksut buying new ones from evwest

Do that instead.

was trying to recycle

Hey, I'm all for it. You've read my other post, so you know I have thousands of recycled laptop cells in use. They're just not going to work for this build, unfortunately. Save them for a 7s or 14s standby battery backup for power outages. Just with the 200 cells, you have enough for 14s28p, call it 1000w max draw, buy a cheap 1000-1500w inverter, there you go.

 

[harrisonpatm]

good idea...ill practice with my spot welder on a small back up battery pack.

i have chance to get these for 2 bucks a piece...
They are new.
Should i just snag these?

SAMSUNG 18650 Batteries
Model# INR18650-33G
Typical Capacity 3,150 mAH.
Minimum Capacity 3,000 mAH.
Nominal Voltage 3.60V
Charging Voltage 4.20V Flat top Positive

thank you for all your help

Have a look at this:

Test of Samsung INR18650-33G 3150mAh (Blue)

It depends on what works for you, but maybe they would work. Note that they're really only good for 6.5a per cell. Which isn't bad. At 10p, 65a max discharge @ 72v nominal, that gives you a max of 4.7kw discharge. Could work.

 

[amberwolf]

Also, keep in mind there are many shady cell vendors out there. Not knowing where you're intending to buy from, we can't help you determine if they're real or not, but you should do some research on the seller and the actual item they are going to ship you to be sure you don't get cheated. It is very common for places to sell recycled garbage battery packs' ripped-out cells as new, and to rewrap junk or noname cells as expensive brandname ones.

So if the deal seems too good to be true, it probably is.

If the cells are priced well below typical market value, there's probably a reason for it.

 

[amberwolf]

Hmm. they don't list the cells you refer to on their site

EV West - We Sell EV Parts but Service is Our Business

www.evwest.com

or in a search for any of the specifics in your post.

But, given the seller, they're probably good, and almost certainly better than the recycled laptop cells for your needs.

 

[amberwolf]

Ah. those aren't the same cells you referred to. These are a different cell, the 25R (rather than the 33G), only 2500mAh typical vs 3000mAh, but should handle twice the current draw.

Test of Samsung INR18650-25R 2500mAh (Green)

 

[amberwolf]

Ah. Well, if they're LGs, they're definitely not hte same, since the ones you link and the ones you mentioned before (in the $2 post) are both Samsung.

FWIW, if you mention or discuss one thing, but are actually talking about something else, it's difficult for us to provide you the correct or even helpful info.

I recommend that when you have a question about something, link the actual something, and provide info about that actual something, rather than another possibly related but different thing.

If you change what you're talking about, state that and link/describe the new thing.

You'll get more useful info faster with less wasted time.

 

[minsk]

The 3k QS motor i bought has a one-sided axle....this present a whole new set of challenges. The hub motor came from an MZ scooter. So i will have to design a one sided swing arm.