new eZip motor

General Discussion about electric bicycles.
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latecurtis   1 GW

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Re: new eZip motor

Post by latecurtis » Mar 26 2020 9:48pm

https://www.ebay.com/i/173844365503?rt= ... %3DDefault

Are these as good as the ones SUNDER posted ?

https://www.aliexpress.com/item/3289147 ... b201603_55

I never ordered from alli express. It says to be careful. i thought Lithiul iron was safer than LiPo ?????

Please let me know. Thanks.

LC out.
I build e bikes. There not always pretty or practical but sometimes they work, at least for awhile. Immortality is not a dream but the future of our evolution. We were given the tools to forge our own destiny. We were created in gods image and shall evolve to live forever.

markz   100 GW

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Re: new eZip motor

Post by markz » Mar 26 2020 9:59pm

No battery is safer then another.

LiPo needs careful attention just as much as LiFePO4 or any other Lithium Ion.

Problem with LiFePO4 (Lithium Iron) is that is heavier and bulkier then LiPo and Lithium Ion. I guess you could say the LiFePO4 is more forgiving then LiPo. You have to be careful with any and all batteries you are using or are putting together.

Go to ru.nkon.nl for 18650 cells, the 25R is a great cell to use, along with the PF cell. They can even tab weld the ends for you, so you can solder on wire to make what you want.

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latecurtis   1 GW

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Re: new eZip motor

Post by latecurtis » Mar 27 2020 10:33pm

Thanks so much.

I will look into that.
I build e bikes. There not always pretty or practical but sometimes they work, at least for awhile. Immortality is not a dream but the future of our evolution. We were given the tools to forge our own destiny. We were created in gods image and shall evolve to live forever.

john61ct   1.21 GW

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Re: new eZip motor

Post by john61ct » Mar 28 2020 1:31am

LFP (LiFePO4) is almost impossible to put into thermal runaway by accident, much safer than either LI or LiPo.

And yes, LiPo a bit more dangerous than LI.

Both much more energy dense where weight & space issues are important.

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Sunder   100 MW

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Re: new eZip motor

Post by Sunder » Mar 28 2020 6:58pm

markz wrote:
Mar 26 2020 9:59pm
No battery is safer then another.
I would disagree with that. No battery is totally safe, but how many fires have been started your standard carbon zinc batteries? How many people have gotten chemical burns or been electrocuted by them?

LTO is not safe, but the risks are different, and I think, overall lower.

@LC, I see you found them anyway. Let me just warn you that those pouches cannot be soldered. You either need to mechanically assemble them, or spot weld them. I will show you some photos a little later of how I did it.

LiFePo4 is another safer than LiPo option, because as John61ct said, they are almost immune from thermal runaway. However, they are less resistant to over-discharge than LTO, and need a lower charge rate. They do have better power density, and are way cheaper than LTO though.

The other options that might work for you is 18650 LTOs. https://lg18650.com/battery-cells/152-l ... h-23v.html

These are even more expensive and lower density than pouch LTOs though.
eBike: Q100H on 16S with Phaserunner FOC Controller
eMotorscooter: Vectrix VX-1 on 36S
eCar: Mitsubishi Outlander PHEV... Waiting for warranty to expire
eHouse: 5.5kw On-grid solar with battery backup coming soon!

After 5 builds, the best advice I can give, is start with high quality products. I prefer http://www.ebikes.ca

john61ct   1.21 GW

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Re: new eZip motor

Post by john61ct » Mar 28 2020 11:19pm


Sunder wrote:LTO is not safe, but the risks are different, and I think, overall lower.
Please expand on that, ideally contrasting with LFP risks and failure modes. Links?


> The other options that might work for you is 18650 LTOs.

Sold out. Other sources? Do you know the manufacturer?

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Sunder   100 MW

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Re: new eZip motor

Post by Sunder » Mar 29 2020 4:15am

Basically, LTO's only major risk to life and property aside from itself, is electrical fire and electrocution, but the latter is common to all packs. I have a pack here that can deliver something like 33kw continuously, and 66kw instantaneously. I once dropped a spanner over only part (maybe 16-18v?) of a 30Ah, 24v, 10C sustained capable pack, so at the very least 5kw (Not sure what the instantaneous rating was, but these had around 1.2-1.4mOhm internal resistance). I had holes in my T-Shirt, scorch marks on an MDF bench, fragments of molten metal and a large chunk taken out of the spanner.

To damage itself, you need to overcharge the cell by at least 50%, but if you do, some toxic gases can build up, but in a well designed cell, this should just vent in tiny amounts at a time. Draining the cell to zero doesn't appear to be a catastrophic failure mode, and in face, aside from a small loss of capacity and increase in resistance, doesn't even damage the cell.

Contrast to LFP? You're already comparing very safe with ultra safe. Both are extremely hard to set on fire - even with external heat sources, but LFP will gas and swell from over-discharging. Not sure if the gases from that are toxic, but I'd assume so too.

With a large enough pack electrical fire is also possible with LFP - In fact, electrical fires are "possible" with the right resistance wire on a AA battery... But considering the voltages these are normally used at, most of the time, if there's accidental contact, the spark will push the metal object away, rather than fuse the object to a terminal to give it time to heat, so the more likely fire risk is from the molten metal coming from the sparking. Not a lot of difference there, except LFP packs tend to be lower C-rates.

Obviously have no stats or anything to back this up, but these are just observations.

And, back to my last post. Here's a photo of how I assembled a 48v, 4Ah pack without soldering:
thumbnail_20200329_160739.jpg
thumbnail_20200329_160739.jpg (232.03 KiB) Viewed 88 times

Close up on the tabs, I've punched a hole through them, and bolted them together.
thumbnail_20200329_160758.jpg
thumbnail_20200329_160758.jpg (201.29 KiB) Viewed 88 times
No reason they had to be nylon bolts, and that's not finished yet - I'm going to tape it all down with foam spacers and insulating tape, and possibly even pot it with hot melt glue, but I'm still cycling it to test for weak cells.
thumbnail_20200329_160745.jpg
thumbnail_20200329_160745.jpg (224.6 KiB) Viewed 88 times
eBike: Q100H on 16S with Phaserunner FOC Controller
eMotorscooter: Vectrix VX-1 on 36S
eCar: Mitsubishi Outlander PHEV... Waiting for warranty to expire
eHouse: 5.5kw On-grid solar with battery backup coming soon!

After 5 builds, the best advice I can give, is start with high quality products. I prefer http://www.ebikes.ca

john61ct   1.21 GW

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Re: new eZip motor

Post by john61ct » Mar 29 2020 10:07am

cool thanks

link to BMS / voltage checker?

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Sunder   100 MW

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Re: new eZip motor

Post by Sunder » Mar 29 2020 5:08pm

That's this one here:

https://www.ebay.com/itm/10S-24S-Smart- ... Ggqh8SgrAg

Image

The smaller (lower current) ones are cheaper, but they seem to be out of stock currently.
eBike: Q100H on 16S with Phaserunner FOC Controller
eMotorscooter: Vectrix VX-1 on 36S
eCar: Mitsubishi Outlander PHEV... Waiting for warranty to expire
eHouse: 5.5kw On-grid solar with battery backup coming soon!

After 5 builds, the best advice I can give, is start with high quality products. I prefer http://www.ebikes.ca

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