Search found 2409 matches

by Sunder
Feb 18, 2018 5:00 am
Forum: Battery Technology
Topic: 18650 questions - How does internal resistance relate to voltage?
Replies: 11
Views: 133

Re: 18650 questions - How does internal resistance relate to voltage?

How does internal resistance relate to voltage? Does it? When there is no load, there is no relationship. Once a load is applied, a battery with a higher internal resistance will have a lower voltage under load, than a battery with a lower internal resistance. A battery with internal resistance is ...
by Sunder
Feb 15, 2018 4:13 pm
Forum: Battery Technology
Topic: Voltage drop with acceleration
Replies: 7
Views: 299

Re: Voltage drop with acceleration

When I get unexpected results, I find doing the reverse maths can bring a sanity check into the situation. Might not help you find the problem, but might tell you whether you're in the ball park for what you're seeing. 4.1v to 3.2v = 0.9v drop 0.9 x 12 = 10.8v drop You've said 500w on a 49.2v system...
by Sunder
Jan 27, 2018 5:23 pm
Forum: Battery Technology
Topic: Two parallel packs made from different C rate cells.
Replies: 4
Views: 204

Re: Two parallel packs made from different C rate cells.

#1 and #2 is ambiguous language, but Dan is right. The lower resistance pack (higher C rate) will provide most power, with the lower C rate sagging and tipping in what it can. When the load is off, the lower C rate pack tops the higher one back up. In extreme cases, becauss the battery itself is pro...
by Sunder
Jan 25, 2018 7:16 pm
Forum: E-Bike General Discussion
Topic: new eZip motor
Replies: 4815
Views: 274366

Re: new eZip motor

Maybe missed the boat on this one, but in my experience, 26650s are not as cost effective as 18650s. 18650s are in everything. you get good economy of scale. Unfortunately you also get a lot of rebirths and fakes for that reason too. Have you had a look at Nissan Leaf cells? They're pretty cheap ove...
by Sunder
Jan 25, 2018 7:00 pm
Forum: Battery Technology
Topic: Is it OK to wire only 10 cells to a 14 cell BMS?
Replies: 11
Views: 330

Re: Is it OK to wire only 10 cells to a 14 cell BMS?

I think Fetcher's signature answers the question better than his post... Test it. what's the worst that could happen? With 4 less cells, there is no chance of over voltage damage. But just in case you are going the 1000 opinions route, BMS Battery's ones allegedly can. I ordered 3 x 12S BMS and they...
by Sunder
Jan 22, 2018 3:34 am
Forum: E-Bike General Discussion
Topic: The winner is . Not what you think
Replies: 37
Views: 973

Re: The winner is . Not what you think

I'm really trying to think from your point of view... Because as I said, I don't really believe that you think that cars are more efficient than trains. The best I can come up with, is that you're fixated on the weight, because I used a throw away number as an example, and you thought it was key to ...
by Sunder
Jan 22, 2018 2:37 am
Forum: E-Bike General Discussion
Topic: The winner is . Not what you think
Replies: 37
Views: 973

Re: The winner is . Not what you think

Edit: post was reply to billvon. Thought I quoted a bit of his post. Ugh. You're picking fights for the sake of it. Even you can't be dumb enough to think cars are more efficient than trains. Average co2 per kilometer for trains 28g Average co2 per kilometer for cars 100-143 depending on assumptions...
by Sunder
Jan 21, 2018 1:19 am
Forum: E-Bike General Discussion
Topic: The winner is . Not what you think
Replies: 37
Views: 973

Re: The winner is . Not what you think

Nothing to do with the efficiency of energy conversion. If trains a century ago were running with only one person in them at a time, yes, I would have said that was shockingly wasteful. Hmm. Modern trains are pretty heavy. A six car Amtrak train plus engine weighs about 1.1 million pounds. Older tr...
by Sunder
Jan 20, 2018 5:23 pm
Forum: Battery Technology
Topic: Chilwee lead-graphene battery
Replies: 19
Views: 411

Re: Chilwee lead-graphene battery

I imagine one day, someone who has been driven to the brink of insanity by coming second every year since 1990, will buy 70lbs of Lithium, gut two very standard looking SLAs, fit them inside then create a tiny layer of acid and lead on top in case a race official tries to remove a valve to inspect o...
by Sunder
Jan 20, 2018 7:19 am
Forum: Battery Technology
Topic: Chilwee lead-graphene battery
Replies: 19
Views: 411

Re: Chilwee lead-graphene battery

amberwolf wrote:
Jan 20, 2018 2:24 am
Archer321 wrote:
Jan 19, 2018 7:25 pm
Gotta have lead.
Rules.
You must live in a really wierd place to require lead-type batteries on your bikes (or other vehicles).
Could be a competition or race?
by Sunder
Jan 19, 2018 10:20 pm
Forum: E-Bike General Discussion
Topic: The winner is . Not what you think
Replies: 37
Views: 973

Re: The winner is . Not what you think

Are you saying the same thing about trains a century ago? Because early steam engines had efficiencies of about 2%; modern gas vehicles approach 40%, and modern EV's approach 90% efficiency (and 50% well to wheels.) Nothing to do with the efficiency of energy conversion. If trains a century ago wer...
by Sunder
Jan 19, 2018 6:50 pm
Forum: Battery Technology
Topic: Chilwee lead-graphene battery
Replies: 19
Views: 411

Re: Chilwee lead-graphene battery

Most sellers are willing to send samples at a higher processing fee.

But unless you must have lead, why go with this, when Lithium batteries of various types out perform on most common characteristics?
by Sunder
Jan 16, 2018 7:31 am
Forum: E-Bike General Discussion
Topic: The winner is . Not what you think
Replies: 37
Views: 973

Re: The winner is . Not what you think

If we were willing to go a bit slower, we could use less massive vehicles and probably have a net gain in safety and use fewer resources. So in that sense, yes, shorter distances would improve things. And lighter slower vehicles are more effective with shorter distances. One day a future generation...
by Sunder
Jan 15, 2018 8:10 pm
Forum: E-Bike General Discussion
Topic: new eZip motor
Replies: 4815
Views: 274366

Re: new eZip motor

OK. Now I got a big question. Scrap metal price for a 2012 PT cruizer is $200. The lady downstairs was scrapping it tommorow as it was towed as it would not go into gear. Either transmission or linkage. I am thinking I might know some friends that can get it running if linkage. not sure about trann...
by Sunder
Jan 11, 2018 6:25 pm
Forum: E-Bike General Discussion
Topic: new eZip motor
Replies: 4815
Views: 274366

Re: new eZip motor

Also I am building a gaming machine for steam games and need a decent video card and 450 or 500 watt power supply. You're seriously tempting me to upgrade. I've had a few unexplained reboots lately, and I can only run games on high detail on 1080p. If I switch to 4K, it only runs on Low-Mid dependi...
by Sunder
Jan 11, 2018 4:28 pm
Forum: Vendor Relations Corner
Topic: Concerns with BMSBattery's Security
Replies: 4
Views: 296

Re: Concerns with BMSBattery's Security

Maybe this borders on paranoid, but I do work in cybersecurity/fraud prevention. Imagine the password you set for BMSB was the same as your email and Paypal password. As Dapuma said, it was automated so no human has seen your password yet. You order a couple high value goods and they're DOA. BMSB be...
by Sunder
Jan 11, 2018 4:16 pm
Forum: Vendor Relations Corner
Topic: Concerns with BMSBattery's Security
Replies: 4
Views: 296

Re: Concerns with BMSBattery's Security

If you recieve a full or partial password, it means your password is not encrypted and visible to admins of the sites as well as any hackers who gain access to the site. Ensure that the password is NOT used for any other account and especially your email. There are criminals out there who have "scan...
by Sunder
Jan 11, 2018 3:14 am
Forum: Battery Technology
Topic: 700 mile charge in 1 minute
Replies: 13
Views: 435

Re: 700 mile charge in 1 minute

Warranty probably says: Battery warranty void if charged above absolute zero.
by Sunder
Jan 11, 2018 3:12 am
Forum: Battery Technology
Topic: MeanWell HLG vs ELG as charger
Replies: 16
Views: 430

Re: MeanWell HLG vs ELG as charger

Yeah. Reading a bit more, it seems even the ELGs hold up under full load on 110v, no derating required. Someone on another forum pointed out that ELGs have a 5 year warranty vs the HLG's 7 year. Also mentioned that each HLG was QA'ed manually, where as ELGs were machine tested. That one I found a bi...
by Sunder
Jan 11, 2018 2:26 am
Forum: Battery Technology
Topic: MeanWell HLG vs ELG as charger
Replies: 16
Views: 430

Re: MeanWell HLG vs ELG as charger

"Derating may be required under low input voltages".

I wouldnt count on the HLG holding up equally on 110v, especially since it also says:

"All parameters [...] measured at 230vac"
by Sunder
Jan 10, 2018 11:50 pm
Forum: Battery Technology
Topic: 700 mile charge in 1 minute
Replies: 13
Views: 435

Re: 700 mile charge in 1 minute

I think the 700 mile in 1 minute is the theoretical "The battery won't catch fire" rate. This newer article here: https://www.express.co.uk/life-style/cars/902345/Fisker-solid-state-electric-car-battery-range-charging-times Says the car should charge 125miles in 9 minutes. I use the reverse measure....
by Sunder
Jan 08, 2018 8:27 pm
Forum: Battery Technology
Topic: Large LiOn from AliExpress?
Replies: 11
Views: 457

Re: Large LiOn from AliExpress?

I recommend OSN power. Many others are dodgy, but these guys have high quality products, good service and nearly the cheapest prices.

If you can't find what you need ask them, and see if they do assembly.
by Sunder
Jan 08, 2018 6:56 am
Forum: Battery Technology
Topic: BMS Battery Alloy Shell Charger Problems
Replies: 597
Views: 40598

Re: BMS Battery Alloy Shell Charger Problems

Have you got the polarity right?

The use a strange reverse connection sensing method, so that when there is no battery connected, it shows the reverse of the expected polarity. its strange and I killed a few fuses that way.
by Sunder
Dec 24, 2017 12:33 am
Forum: Battery Technology
Topic: Speculate what happened to my cells
Replies: 11
Views: 422

Re: Speculate what happened to my cells

2 years, but only in service for 1.
by Sunder
Dec 23, 2017 9:16 pm
Forum: Battery Technology
Topic: Speculate what happened to my cells
Replies: 11
Views: 422

Re: Speculate what happened to my cells

I'm a little lost. 8s 23p = 184 cells, and if you look carefully, one entire 23p row puffed. It's just 4 in the foreground, but you can see more puffed in the back ground.

All cells in the first row puffed, none in the other rows puffed.