Search found 3615 matches

by jonescg
May 21 2021 6:07am
Forum: Battery Technology
Topic: 18650/21700 Case Material?
Replies: 40
Views: 763

Re: 18650/21700 Case Material?

flippy wrote:
May 16 2021 5:59am

i tested bunch of setups triggering a ptc with a 2 part epoxy on the cell. the results were....violent.
Got video? I'd love to see it.
by jonescg
May 16 2021 5:08am
Forum: Battery Technology
Topic: 18650/21700 Case Material?
Replies: 40
Views: 763

Re: 18650/21700 Case Material?

Nothing wrong with potting a cylindrical cell pack. In fact I'd argue it's the safest thing to do. The PTC plate will function just fine in most cases.
by jonescg
Apr 25 2021 8:20am
Forum: Battery Technology
Topic: Soldering with a spot welder...
Replies: 5
Views: 403

Re: Soldering with a spot welder...

The solder paste will explode and the tab won't bond. Have a go yourself, but wear safety glasses.
by jonescg
Apr 04 2021 7:44am
Forum: Forum Rules and Features
Topic: Big update to the biker bar & order of the forums
Replies: 54
Views: 1740

Re: Big update to the biker bar & order of the forums

The evolution of DIY eh?

Happy to see a few threads nuked. They offer nothing new except more consipracy thories and wild politics.

But focus on DIY is good 👍
by jonescg
Mar 26 2021 11:39pm
Forum: Alternative Energy
Topic: NEC 690: 50Vnom max vs 16s LiFePO4
Replies: 1
Views: 164

Re: NEC 690: 50Vnom max vs 16s LiFePO4

In Australia we have the following definitions: Low Voltage: Anything under 1000 V AC or 1500 V DC. High Voltage: Anything over 1000 V AC or 1500 V DC. Only a licensed electrician may work on a fixed installation with more than 120 V DC or 50 V AC. Note the highlights - EVs are exempt :) 120 V DC is...
by jonescg
Mar 26 2021 11:31pm
Forum: Alternative Energy
Topic: My DIY battery storage system
Replies: 42
Views: 9911

Re: My DIY battery storage system

Hi @stirucherai, It's a solid inverter, and highly recommended for these applications. In the PVMaster app, I chose "User Defined". It reminds you that you're taking your own risks blah blah... But you can just ender the Ah and critically, set Vmax. The Float voltage is about 2 volts lower...
by jonescg
Mar 23 2021 6:15am
Forum: Forum Rules and Features
Topic: Big update to the biker bar & order of the forums
Replies: 54
Views: 1740

Re: Big update to the biker bar & order of the forums

I like the new structure.
Top work Nep :thumb:
by jonescg
Mar 23 2021 6:11am
Forum: Large EV General Discussion
Topic: 1988 Honda Prelude conversion - fastest build log ever.
Replies: 43
Views: 7823

Re: 1988 Honda Prelude conversion - fastest build log ever.

Well of the 8 modules, two were toast and I had one spare. They went to a friend's house where he's using them as a home storage system. Don't worry, they're well separate from the house and inside a fireproof cabinet. So far so good - no grief at all with them. I'm not really building batteries for...
by jonescg
Mar 22 2021 8:09am
Forum: Large EV General Discussion
Topic: 1988 Honda Prelude conversion - fastest build log ever.
Replies: 43
Views: 7823

Re: 1988 Honda Prelude conversion - fastest build log ever.

Pleased to report this battery was finally built and installed last week.
New Pack built sml.jpg
New Pack built sml.jpg (183.94 KiB) Viewed 259 times
The owner drove it off into the sunset, and I hope I never need to look at it again.

https://youtu.be/WRPXfSc43no
by jonescg
Mar 21 2021 5:32am
Forum: Battery Technology
Topic: Balance Wire placenment
Replies: 15
Views: 501

Re: Balance Wire placenment

In the second diagram, the BMS attachment point can be anywhere on that link, even on the end of one of the cells. The voltage difference will be negligible.
by jonescg
Mar 20 2021 10:12pm
Forum: Battery Technology
Topic: Balance Wire placenment
Replies: 15
Views: 501

Re: Balance Wire placenment

Series first or parallel.png
Series first or parallel.png (6.56 KiB) Viewed 264 times
BMS attachment points in orange.

I highly recommend the second option for any battery pack.
by jonescg
Mar 19 2021 7:07pm
Forum: Battery Technology
Topic: Balance Wire placenment
Replies: 15
Views: 501

Re: Balance Wire placenment

Because all 4 cells will be at roughly the same voltage. Measure one you measure them all.
by jonescg
Mar 16 2021 6:13pm
Forum: Battery Technology
Topic: Balance Wire placenment
Replies: 15
Views: 501

Re: Balance Wire placenment

Think of it as a direct connection to each cell. It's main job is to monitor cell voltages. If it goes out of spec, it responds.
The leads are at high potentials, so make sure they can't touch anything.
by jonescg
Mar 16 2021 8:49am
Forum: Battery Technology
Topic: jonescg's cylindrical cell build thread
Replies: 65
Views: 3320

Re: jonescg's cylindrical cell build thread

fechter wrote:
Mar 16 2021 8:26am
Nice. Any idea what the total battery weight is?
Each module weighed 33 kg. The rest of the enclosure and all the gubbins added about 25 kg, so the whole 25 kWh pack weighs about 160 kg I guess? Not bad considering the original Leaf battery stored as much energy and weighed about 300 kg.
by jonescg
Mar 16 2021 4:35am
Forum: Battery Technology
Topic: jonescg's cylindrical cell build thread
Replies: 65
Views: 3320

Re: jonescg's cylindrical cell build thread

The Second Coming.jpg Battery is in, the car drives just fine and the range is prettymuch right where it used to be. Comfortable 150 km under normal circumstances, 170 km under ideal and 120 km under testing conditions. The battery puts out ~55 kW, which is enough to get moving smartly, and it take...
by jonescg
Mar 11 2021 6:15am
Forum: Battery Technology
Topic: Best Method for Battery Build??? 16s4p Telsa 2170 Cells
Replies: 36
Views: 4126

Re: Best Method for Battery Build??? 16s4p Telsa 2170 Cells

sukko's are a joke. you need a kweld with a kcap or bigger to do this. You know, when I was welding nickel tabs to nickel-coated aluminium busbars, the only welder that did the job was the Sunkko. Capacitive welders just vaporised the tabs while the old transformer just hummed and stuck it on (sati...
by jonescg
Mar 10 2021 1:33am
Forum: Battery Technology
Topic: Single Cell Battery
Replies: 6
Views: 362

Re: Single Cell Battery

There are other compromises though - so things like 24 V or 36 V for an e-bike, or 72 V to 96 V for an e-moto are perfectly reasonable. There's no good reason to exceed 400 V for a sub-megawatt system nowadays. I ran the race bike on 700 V fully charged as that was the best compromise of power and v...
by jonescg
Mar 07 2021 10:19pm
Forum: Battery Technology
Topic: jonescg's cylindrical cell build thread
Replies: 65
Views: 3320

Re: jonescg's cylindrical cell build thread

Almost ready to install!
2021-03-07.jpg
2021-03-07.jpg (181.58 KiB) Viewed 296 times
by jonescg
Mar 06 2021 9:42pm
Forum: EV Business World
Topic: Hyundai Ioniq 5...
Replies: 4
Views: 511

Re: Hyundai Ioniq 5...

1600 kg towing rating too! I know a dozen people wiling to buy an EV as long as it comes with a tow ball, but so far nothing...
This car looks :bigthumb:
by jonescg
Feb 23 2021 9:54pm
Forum: Battery Technology
Topic: jonescg's cylindrical cell build thread
Replies: 65
Views: 3320

Re: jonescg's cylindrical cell build thread

It was actually US$500 for 2x10 kg (parts A and B) but the shipping was another US$200.

I think it's filled with boron trinitride, and almost certainly aluminium oxide. 1.2 W/mK and good adhesive properties is pretty nice.
The fillers make a big difference in price, and thermal conductivity :)
by jonescg
Feb 23 2021 4:30am
Forum: Battery Technology
Topic: jonescg's cylindrical cell build thread
Replies: 65
Views: 3320

Re: jonescg's cylindrical cell build thread

It's a product from U-Sheen in China. S8960 as a two part adhesive resin.
1.2 W/mK which is not bad. Fairly affordable too, but minimum order is 20 kg for US $700.
by jonescg
Feb 22 2021 7:45am
Forum: Battery Technology
Topic: jonescg's cylindrical cell build thread
Replies: 65
Views: 3320

Re: jonescg's cylindrical cell build thread

It would have probably helped in this case, but surely the equivalent would be putting one electrode on the busbar and the other on the nickel tab. I did this often and it made little difference to the weld quality. I think in future I'll use copper with nickel tabs. And bigger cells so there's less...
by jonescg
Feb 21 2021 5:04am
Forum: Battery Technology
Topic: jonescg's cylindrical cell build thread
Replies: 65
Views: 3320

Re: jonescg's cylindrical cell build thread

Last module done.jpg 30,000 spot-welds later it's done. A friend came around with a capacitive discharge welder and it was surprisingly bad at welding tabs to the nickel plated busplates. We swapped the two copper rods for the spare hand piece and it simply vapourised the nickel and stuck nothing t...
by jonescg
Feb 15 2021 2:21am
Forum: Battery Technology
Topic: jonescg's cylindrical cell build thread
Replies: 65
Views: 3320

Re: jonescg's cylindrical cell build thread

So I am 7/8ths of the way through this battery build and the last lot of busbars are the worst. They are severely passivated so nothing will stick to them. I found another soldering technique where you can effectively plate the aluminium with copper using FeCl 3 solution and CuSO 4 . It looks like a...
by jonescg
Feb 09 2021 8:41am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 534
Views: 89688

Re: Spot Welding Copper Strips to 18650 Battery Cells

Why might this welder work on .4 mm copper at those settings and the kWeld won't? I'm not home right now but have welded thinner copper using the "sandwich" technique at those energy levels (not sure of the pulse time) but I'm pretty sure it wouldn't work for .4 mm thick stuff. I'm assumi...