Search found 81 matches

by helpfulguy
Mar 25 2019 5:19pm
Forum: Battery Technology
Topic: LiFePo4 starter battery BMS with only 2 leads?
Replies: 20
Views: 819

Re: LiFePo4 starter battery BMS with only 2 leads?

This is interesting. Conclusion is: I need a low voltage cutoff. Either a stand-alone LVC, or a BMS which include LVC functionality. Current wire harness have 3 cables: - Positive - High amp cable straight to starter motor (60-70A peak during crank, 20A continious) - Positive - Low amp cable through...
by helpfulguy
Mar 19 2019 3:52pm
Forum: Battery Technology
Topic: LiFePo4 starter battery BMS with only 2 leads?
Replies: 20
Views: 819

Re: LiFePo4 starter battery BMS with only 2 leads?

dogman dan wrote:
Mar 19 2019 6:45am
yes, you need a bms with just two leads, for it to use the scooters positive input to charge when it runs.

Thanks buddy, I wasn't even sure those existed, what term should I search for to find them? Any actual item suggestions? I need 100A I think.
by helpfulguy
Mar 18 2019 8:55pm
Forum: Battery Technology
Topic: LiFePo4 starter battery BMS with only 2 leads?
Replies: 20
Views: 819

LiFePo4 starter battery BMS with only 2 leads?

Hello, I previously did this for my 400cc single cylinder motorcycle and it worked great: 4s A123 26650 No BMS I just dropped it in, and it worked great, cranked it like nothing. I now need for my small 70cc. Problem: It is not uncommon for old scooters to have "leak" short circuits that drain the b...
by helpfulguy
Jan 14 2018 11:16am
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1625
Views: 193028

Re: Thread for new battery breakthrough PR releases

Nothing wrong with that.... anything positive about that? Of course not. Powerbanks are often made with defective cells discarded for better use. I wish we had graphene available for our battery packs. That's all. Nothing to worry about and Nothing to celebrate either. I wish Nothing but the best f...
by helpfulguy
Jan 14 2018 7:15am
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1625
Views: 193028

Re: Thread for new battery breakthrough PR releases

https://www.kickstarter.com/projects/anywatt/apollo-worlds-first-graphene-battery-usb-c-pd-powe?lang=es The FIRST graphene battery is a powerbank? 😨 I really wish I am wrong. But tell me why this sound wrong: Are you telling me, that a small company from nowhere asking consumers for up-front $10,00...
by helpfulguy
Dec 13 2017 3:48am
Forum: Battery Technology
Topic: Super glue nickel strips to 18650?
Replies: 13
Views: 1284

Re: Super glue nickel strips to 18650?

This makes Sense. I Guess you can use multiple of the thin wires to spread out current/heat if you are worried. One thing I tried but my soldering iron too weak/broken, to pre solder the battery as well as nickel, then put the two together,heating nickel from above till they merge. Didn't work but t...
by helpfulguy
Dec 11 2017 6:03pm
Forum: Battery Technology
Topic: Super glue nickel strips to 18650?
Replies: 13
Views: 1284

Super glue nickel strips to 18650?

Tldr; Can you adequately reliably superglue nickel strips to poles to make battery pack? Bear with me, novel mood, so bare with us: In my possesion: 100% lack of spot welder and equal amount of patience Broken regular welder from around ww1 (seriously, bakelite, no components, directly to mains), wi...
by helpfulguy
Dec 06 2017 4:54am
Forum: E-Bike General Discussion
Topic: Run motor with insufficient amp batteries damaging?
Replies: 12
Views: 993

Re: Run motor with insufficient amp batteries damaging?

Gool Gool guys, interesting discussion! I made some more research: Hard to find 4s bms with 200A+ My 100A BMS will take 150A burst Some commercially starter batteries have these a123 26650 lifepo4 cylindrical cells without bms Opens up discussion - maybe bms not needed? they wont unbalance I presume...
by helpfulguy
Dec 05 2017 3:49pm
Forum: E-Bike General Discussion
Topic: Run motor with insufficient amp batteries damaging?
Replies: 12
Views: 993

Re: Run motor with insufficient amp batteries damaging?

With A123 cells, I wouldn't worry about it much as you won't be running the motor for long periods of time. If you draw too much current from any battery, it can overheat and possibly be damaged or catch fire. Thanks fechter! Ok, so I hook up A123 cells with 100A bms board, and it should be good as...
by helpfulguy
Dec 05 2017 3:47pm
Forum: E-Bike General Discussion
Topic: Run motor with insufficient amp batteries damaging?
Replies: 12
Views: 993

Re: Run motor with insufficient amp batteries damaging?

what kind of current limiting device would be good here, while being reliable and keeping cost minimal? What is your application? Sounds like you're not using a controller, so is this just a replacement for the lead-acid battery in a normal gasoline motorcycle? Correct! I want to use this as a lear...
by helpfulguy
Dec 05 2017 11:16am
Forum: E-Bike General Discussion
Topic: Run motor with insufficient amp batteries damaging?
Replies: 12
Views: 993

Re: Run motor with insufficient amp batteries damaging?

If the BMS does it's job, it will shut down the battery at any draw over 100 amps. But it's designed as a safety device, not a means of current control, and i wouldn't rely on it. You should be relying on a controller, not the BMS to handle the current draw. Thanks drunk - what kind of current limi...
by helpfulguy
Dec 04 2017 10:11pm
Forum: E-Bike General Discussion
Topic: Run motor with insufficient amp batteries damaging?
Replies: 12
Views: 993

Run motor with insufficient amp batteries damaging?

If you have 200A capable motor but only 100A burst/70A sustain batteries and 100A bms - will you risk damaging batteries and or bms, or will motor only get 100A? Have 4x A123 cells 70A rated 200A burst, with 100A bms. Will connect to motorcycle starter motor which is somewhere between 70-200A depend...
by helpfulguy
Nov 30 2017 1:14am
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1625
Views: 193028

Re: Safe lipos incoming!

I was looking for such a forum where one can post news like this and discuss it, but found none. I only found Battery Technology.
by helpfulguy
Nov 29 2017 5:53am
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1625
Views: 193028

Safe lipos incoming!

Excerpt: The university’s researchers found that lithium ion batteries, commonly used in phones and electric cars, as well as the rechargeable sodium-ion units, make use of organic electrolytes to facilitate the flow of the electrical charge. The presence of lithium salts and solvents in the electro...
by helpfulguy
Nov 26 2017 7:30am
Forum: Battery Technology
Topic: BMS selection - protecting DIY battery pack from overcurrent?
Replies: 0
Views: 377

BMS selection - protecting DIY battery pack from overcurrent?

Want to make a 12v starter battery for motorcycle, for fun. Starter motor can draw 200A (CCA in sla terms). 100A is enough to start engine, so I am aiming at 100A to keep cost below $60-80 in total. I want reliable lifepo4. Seem like 4s1p A123 cells peaking 100A is most reliable choice. They are $12...
by helpfulguy
Sep 13 2017 5:00am
Forum: Large EV General Discussion
Topic: This might be a great donor car model
Replies: 7
Views: 1314

This might be a great donor car model

So I just read that cars with rotary engines/wankel engines require a lot of maintenance and break down a lot. Making the market full of good condition "useless" cars. Useless unless you want a perfect condition car, without ICE engine, for peanuts. Cool model Mazda RX8, I Googled "Mazda rx8 without...
by helpfulguy
Jun 23 2017 7:29pm
Forum: Battery Technology
Topic: Easy questions - fun ICE motorcycle starter battery DIY
Replies: 3
Views: 623

Re: Easy questions - fun ICE motorcycle starter battery DIY

1: yes 2: 12.6v is an absolute maximum for 3s liion. If you feed it more you are at real risk of a fire at some stage. Relying on a bms to cut off the charge when full is never a good idea with a constant over voltage supply. If it doesn't then you have a big problem. A 12.6v regulated supply plus ...
by helpfulguy
Jun 23 2017 4:40am
Forum: Battery Technology
Topic: Easy questions - fun ICE motorcycle starter battery DIY
Replies: 3
Views: 623

Easy questions - fun ICE motorcycle starter battery DIY

First project to learn make battery packs. I'm want to tinker together a simple replacement for 12v 5Ah SLA motorcycle starter battery using 18650, bms and vruzend becuse i dont have spot welder. Can solder but I suck big time. Starter motor is ~400w - calculating 600w for margin/light bulbs before ...
by helpfulguy
Dec 06 2016 8:09pm
Forum: E-Bike General Discussion
Topic: Battery Cost
Replies: 26
Views: 2172

Re: Battery Cost

wesnewell wrote:At $2.50 a gallon
That's about half price compared to Europe, which might make things more understandable.
http://www.globalpetrolprices.com/gasoline_prices/
by helpfulguy
Jul 13 2016 9:19pm
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1625
Views: 193028

Graphene batteries may slash your phone recharge time to 15

The regular hype bullshit or the real thing this time?

"Graphene batteries may slash your phone recharge time to 15 minutes"

http://www.digitaltrends.com/mobile/don ... arge-news/
by helpfulguy
Jul 07 2016 7:58pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: Honda Ruckus conversion plans..
Replies: 20
Views: 6626

Re: Honda Ruckus conversion plans..

Ruckus is ~3kw, 50cc drivetrain will not handle this power according to previous builder who tried a 80100 motor (7kw) scooter conversion with a dream to manufacture conversion kits. His bottom line was he had to scratch the idea - drivetrain too weak. Not sure it was belt, clutch or gears. Even if ...
by helpfulguy
May 03 2016 3:57pm
Forum: Battery Technology
Topic: Charge batteries only to 80% = 4x more cycles?
Replies: 37
Views: 3349

Charge batteries only to 80% = 4x more cycles?

Is this correct? If it is, it should be a good way to increase battery life - add 25% energy into your pack and set charger to 80% = profit? "The battery is rated for 1200 cycles at 0-100% charge until it reaches the 80% of the capacity or 5000 cycles when used 0-80% charge." Source: http://hybridau...
by helpfulguy
Mar 18 2016 5:49pm
Forum: E-Vehicles General Discussion
Topic: New ebike/motorcycle/cross?
Replies: 1
Views: 446

New ebike/motorcycle/cross?

Price is nice! Anyone have any info on these? Seem solid! What motor/controller - do we recognise it? Is the bike just a branded chinese product?
http://freerider.kuberg.com/
by helpfulguy
Jan 16 2016 11:33am
Forum: General Discussion
Topic: Improvements to forum
Replies: 0
Views: 230

Improvements to forum

ES is great. It have grown fast and some parts of the forum which worked great for a small number of users and posts, have now gladly grown larger and outgrown its flat layout. Some much needed reconstruction would improve it, making it easier for people to discuss, share and read information. I hav...
by helpfulguy
Jan 16 2016 11:10am
Forum: Battery Technology
Topic: News: Panasonic To Invest $1.6 billion On Tesla Gigafactory
Replies: 10
Views: 1139

News: Panasonic To Invest $1.6 billion On Tesla Gigafactory

This business decision will certainly have a large impact on batteries:
"Panasonic To Invest $1.6 billion On Tesla Battery Gigafactory in Nevada"

http://www.teslarumours.com/2016/01/pan ... on-on.html