Search found 3456 matches

by john61ct
Apr 04 2020 8:07pm
Forum: Battery Technology
Topic: Lithium battery question
Replies: 81
Views: 4771

Re: Lithium battery question

I have a question about the BMS, but I couldn't find a straight answer. The BMS's rated current is 60A, but my controller is able to draw 100A. Please link to the specs or source page for the specific BMS you are referring to. Many do not limit current but just shut down operations or burn at some ...
by john61ct
Apr 04 2020 4:33pm
Forum: Vendor Relations Corner
Topic: Ebird Store -- Amazon & Aliexpress only? That's hard to trust.
Replies: 4
Views: 68

Re: Ebird Store -- Amazon & Aliexpress only? That's hard to trust.

You are absolutely dreaming if you think you can buy stuff online direct from China at ridonculously cheap pricing, remain "anonymous" AND be able to be covered in practice by any kind of warranty. There is no such enforcement of "implied obligation" to protect consumers by any effective government ...
by john61ct
Apr 04 2020 4:18pm
Forum: EV Business World
Topic: Crowd funding DIY Prototype Insurance Sovereign Being
Replies: 2
Views: 37

Re: Crowd funding DIY Prototype Insurance Sovereign Being

That whole "legalistic" approach is a silly scam, useless except to the scammers promoting it. What you need is to get the hobbyists together with the "cars are bad" livability / urban design and Green activists together, and organize political awareness campaigns to get the "powers that be" to see ...
by john61ct
Apr 04 2020 8:58am
Forum: Battery Technology
Topic: charger not working (Electric Motion)
Replies: 4
Views: 331

Re: charger not working (Electric Motion)

Just replace that pack with new is best, replace the BMS or at least wire the new pack so it is easily replaced Then you can take your time, atomise the old one, test cells see if any worth salvaging maybe end up with a spare more likely build them into a portable powerpack for less demanding uses l...
by john61ct
Apr 03 2020 11:23am
Forum: E-Bike Build Threads / Photos & Video
Topic: E-S Stealth Electric Bike Owners
Replies: 16887
Views: 1825887

Re: E-S Stealth Electric Bike Owners

That big initial V drop is likely just surface charge, not significant SoC/Ah capacity utilization. Charging to 4.05V is really better for longevity anyway. I need regen to always work well for drag breaking heavy loads down long mountain roads. Rather than using the battery, considering just 1000W ...
by john61ct
Apr 03 2020 11:07am
Forum: Battery Technology
Topic: What would happen in this scenario?
Replies: 10
Views: 217

Re: What would happen in this scenario?

what would happen if you slightly over stress too weak cells without a bms or cycle analyst? 50A for a pack (perhaps optimistically?) rated for 30A is not what I would call "slightly". Best case you reduce lifespan by **a lot**. Maybe it only sags a bit but performance is "good enough" IMO more lik...
by john61ct
Apr 03 2020 10:55am
Forum: Battery Technology
Topic: Is there a BMS for only charging?
Replies: 17
Views: 314

Re: Is there a BMS for only charging?

Are you recommending these? did you even read my post in reply to the poster that linked them? Yes, I meant independently of the OP use case, all the requirements for use fit my preferences just fine, just asking if build quality / reliability / accuracy is good or not? Not a protective BMS, just a...
by john61ct
Apr 03 2020 10:00am
Forum: Battery Technology
Topic: LiFeMnPo4, adding manganese to LFP
Replies: 2
Views: 101

Re: LiFeMnPo4, adding manganese to LFP

Buy direct here https://gbsystem.m.en.alibaba.com if your location has no trusted local sourcing
by john61ct
Apr 03 2020 9:59am
Forum: Battery Technology
Topic: LiFeMnPo4, adding manganese to LFP
Replies: 2
Views: 101

Re: LiFeMnPo4, adding manganese to LFP

Yes been a while, also "Powerizer". Winston's also claimed benefits for their "special" Yttrium doping, e.g. lower temp tolerance. Color me cynical, marketing differentiation? Never seen trusted testing confirmation of those claims. But higher density can be objectively verified without risking dest...
by john61ct
Apr 03 2020 3:11am
Forum: Battery Technology
Topic: What would happen in this scenario?
Replies: 10
Views: 217

Re: What would happen in this scenario?

The 60V rating must be there for a reason, other components not 100V rated?

If you end up pulling 50A you'll stress those too-weak cells, if you can't program the controller to limit current, consider using a CAv3 to do so, to protect the pack longevity.
by john61ct
Apr 03 2020 3:02am
Forum: Battery Technology
Topic: Is there a BMS for only charging?
Replies: 17
Views: 314

Re: Is there a BMS for only charging?

these https://www.ebay.com/itm/Li-ion-Lifepo4-Battery-Active-Equalizer-BMS-1-2A-Balance-4S-2S-8S-12V-16-8V-24V/113890432488 that were just being talked about right before your post, are not chargers, so they can be connected all the time Are you recommending these? Look very useful for midpoint or ...
by john61ct
Apr 03 2020 2:50am
Forum: E-Bike General Discussion
Topic: DIY vs. Commercial: How/ Why(not)?
Replies: 33
Views: 1010

Re: DIY vs. Commercial: How/ Why(not)?

Personally I'm satisfied, for myself, but in the spirit of helping you, I stand by what I wrote, even if your intentions are pure.
john61ct wrote:Don't take this wrong, do what you like

but IMO such an enthusiastic promotional tone by the author reduces the credibility of the project.
by john61ct
Apr 02 2020 10:26pm
Forum: E-Bike Build Threads / Photos & Video
Topic: E-S Stealth Electric Bike Owners
Replies: 16887
Views: 1825887

Re: E-S Stealth Electric Bike Owners

Regen requires a certain amount of Ah discharged, or has nowhere to put it

you do **not** want your pack getting overcharged!
by john61ct
Apr 02 2020 9:07pm
Forum: E-Bike General Discussion
Topic: Converting a beach cruiser with front wheel motor.
Replies: 24
Views: 233

Re: Converting a beach cruiser with front wheel motor.

Whatever you gotta do!

Stopping is a higher priority than going.

thanks for the details.
by john61ct
Apr 02 2020 8:38pm
Forum: Battery Technology
Topic: Is there a BMS for only charging?
Replies: 17
Views: 314

Re: Is there a BMS for only charging?

Chargers over 10S are getting rarer and rarer, limits your options wrt value, features and build quality.

Better IMO to get a 6S or 8S and then a 10S if you're in a hurry, maximum future flexibility.

Connecting serially for use should be NBD
by john61ct
Apr 02 2020 8:25pm
Forum: E-Bike Technical
Topic: Reention POLLY DP-6C - 70 cell battery case - how fit BMS?
Replies: 10
Views: 1269

Re: Reention POLLY DP-6C - 70 cell battery case - how fit BMS?

Safety depends on where the bike is, not locks nor any anti-theft hardware.

Social norms, culture, that sort of thing.

Amsterdam, yes just make it inconvenient.

Detroit, carry the bike upstairs.
by john61ct
Apr 02 2020 8:21pm
Forum: E-Bike General Discussion
Topic: DIY vs. Commercial: How/ Why(not)?
Replies: 33
Views: 1010

Re: DIY vs. Commercial: How/ Why(not)?

Here the power that comes with the flexibility on DIY and OpenSource on TSDZ2: That dude and his posts are annoying. The open source firmware is very cool, but who the hell pushes it like a used car salesman AND puts pictures of himself and his family in the same post? I'm confused and wondering wh...
by john61ct
Apr 02 2020 3:30pm
Forum: E-Bike General Discussion
Topic: Converting a beach cruiser with front wheel motor.
Replies: 24
Views: 233

Re: Converting a beach cruiser with front wheel motor.

That coaster brake will become pretty irrelevant for hard stops at 25+mph. Add a good front brake whichever way you go on the motor. I agree PAS over throttle, cheap hub OK but get a CAv3 and/or high quality controller in there. If the budget's not there to do it at least minimally right then just w...
by john61ct
Apr 02 2020 8:43am
Forum: Battery Technology
Topic: Homemade Battery Packs
Replies: 1679
Views: 497964

Re: Homemade Battery Packs

Yes a custom enclosure could be water resistant, still have hot swap convenience.

Just not space efficient leaving them in their OEM packs, many just strip out the cells to do regular spot weld packs.
by john61ct
Apr 02 2020 5:57am
Forum: E-Bike General Discussion
Topic: DIY vs. Commercial: How/ Why(not)?
Replies: 33
Views: 1010

Re: DIY vs. Commercial: How/ Why(not)?

Don't take this wrong, do what you like

but IMO such an enthusiastic promotional tone by the author reduces the credibility of the project.
by john61ct
Apr 02 2020 5:40am
Forum: Battery Technology
Topic: Is there a BMS for only charging?
Replies: 17
Views: 314

Re: Is there a BMS for only charging?

They cannot be connected during use, not a BMS, they are chargers. And can be used for bulk-only, no balance too.. Just limit the parallel charging to when it's required. Doing one at a time is safer, more precise, that's when you keep an eye on their SoH. There are also chargers that will do packs ...
by john61ct
Apr 02 2020 5:29am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 381
Views: 37931

Re: Li-ion cells cycle ageing

Seems to be there is a tendency for the lower resistance (higher power) cells to lose capacity more quickly?
by john61ct
Apr 01 2020 8:35pm
Forum: Battery Technology
Topic: Is there a BMS for only charging?
Replies: 17
Views: 314

Re: Is there a BMS for only charging?

A BMS is at minimum LVC / HVC functionality, so by definition, No. Only super expensive ones are designed to actually manage the charge process as part of their functions, and usually the slave charger is as well. A balance charger is what you are thinking of, and there are hundreds that will do the...
by john61ct
Apr 01 2020 5:43pm
Forum: E-Bike Technical
Topic: Rohloff & other IGH at high power - measuring & limiting torque?
Replies: 12
Views: 300

Re: Rohloff & other IGH at high power - measuring & limiting torque?

If you just want to know exactly how much torque the hub can take, you could use a torque wrench on the crank to apply a known torque. I would assume the mfg spec is pretty close. Looking to measure the torque **as produced** by my drivetrain, so I can tune the controller (or CAv3) to stay below th...
by john61ct
Apr 01 2020 5:21pm
Forum: Items for Sale - New
Topic: Toshiba SCIB LTO Battery Pack x2 (32 cells)
Replies: 4
Views: 1014

Re: Toshiba SCIB LTO Battery Pack x2 (32 cells)

tylerwatts wrote:Do you have a link to the original sale or datasheet?
https://lmgtfy.com/?q=toshiba+scib+20Ah+data-sheet