Search found 6244 matches

by john61ct
Mar 03 2019 11:01am
Forum: Battery Technology
Topic: Novice batt builder question
Replies: 32
Views: 2066

Re: Novice batt builder question

My preference is parallel first at the lowest level. They self-balance at rest there at the per-cell level. Once you have strings (serialized, higher voltage) I would not parallel more than 3-4 of those, balancing becomes more of an issue long term. But you should periodically check per-cell health ...
by john61ct
Mar 03 2019 8:48am
Forum: Battery Technology
Topic: Novice batt builder question
Replies: 32
Views: 2066

Re: Novice batt builder question

Long as you get that 16S8P = 128 cells.



Penny dropped with a real Thud there 8-)
by john61ct
Mar 03 2019 7:28am
Forum: Battery Technology
Topic: Novice batt builder question
Replies: 32
Views: 2066

Re: Novice batt builder question

Yes, just like with 6V GC batts, pairs in series makes 12V, need 8 to get to 48V. Each of those is **one string**, same Ah capacity as the component single cell, say 200Ah. Now to increase Ah capacity say you want 800Ah, you need 4x those strings. So 2S4P means 8 total 6V units at 12V, or 8S4P is 32...
by john61ct
Feb 28 2019 8:21am
Forum: Battery Technology
Topic: 3rd ebike battery. This time, doing it right
Replies: 101
Views: 8944

Re: 3rd ebike battery. This time, doing it right

An overtemp cutoff might be a good idea too?
by john61ct
Feb 28 2019 8:20am
Forum: Battery Technology
Topic: 3rd ebike battery. This time, doing it right
Replies: 101
Views: 8944

Re: 3rd ebike battery. This time, doing it right

No bank / pack-level LV cutoff?
by john61ct
Feb 27 2019 6:30pm
Forum: Battery Technology
Topic: Rectifier Huawei R4850G2 48V 42~58V 3000w
Replies: 140
Views: 30327

Re: Rectifier Huawei R4850G2 48V 42~58V 3000w

Someone who knows what they're doing please sell these all ready to go with the V & A display and physical controls

Make a profit of course
by john61ct
Feb 27 2019 5:39pm
Forum: Battery Technology
Topic: Build your own charger
Replies: 153
Views: 15104

Re: Build your own charger

Yes, different cost vs risk profiles. With the industrial / telco class gear, plenty of rectifier modules go cheap, but the rack enclosures can be very pricey. As I said, My goal is 3-4 kW @ 48-60V Pretty hard to get there with quality for under a grand, so an extra hundred or two for the proper con...
by john61ct
Feb 27 2019 5:30pm
Forum: Battery Technology
Topic: Laptop PSU with 60v+battery packs
Replies: 8
Views: 679

Re: Laptop PSU with 60v+battery packs

And what's your need for 5V?
by john61ct
Feb 27 2019 5:29pm
Forum: Battery Technology
Topic: Laptop PSU with 60v+battery packs
Replies: 8
Views: 679

Re: Laptop PSU with 60v+battery packs

I doubt you're doing any serious charging with 5A current @12Vdc? that's just 60W.

If you mean 5A at 115Vac OK, but then I never heard of any laptops going much past 200W especially these days?

20-30A is usually considered at the low end right?
by john61ct
Feb 27 2019 3:06am
Forum: Battery Technology
Topic: BC168 Balance Charger to 4.35V any luck?
Replies: 2
Views: 370

Re: BC168 Balance Charger to 4.35V any luck?

What is the normal range of adjustability for termination voltage?

I'm trying to find a bulk source for the regular model, plenty of vendors day they can get, then come back and say no.

Maybe discontinued by the maker?

by john61ct
Feb 25 2019 9:14am
Forum: Battery Technology
Topic: what does it mean when the LVC function stops working like it should?
Replies: 4
Views: 415

Re: what does it mean when the LVC function stops working like it should?

Yes as a pack wears (loses Ah capacity) the voltage drop correlating with a given SoC becomes earlier and earlier in the discharge cycle. Starting out with a larger Ah pack will stretch out that deterioration, stopping discharge at average say 30% SoC can be double the cycling lifespan of going lower.
by john61ct
Feb 24 2019 1:59pm
Forum: Battery Technology
Topic: Laptop PSU with 60v+battery packs
Replies: 8
Views: 679

Re: Laptop PSU with 60v+battery packs

What sort of load devices and Amp ranges are you looking to supply at 5V?

At 12V?

By laptop "PSUs" do you mean the power bricks usually fed by mains?

Or the internal charging control circuitry?
by john61ct
Feb 24 2019 1:41pm
Forum: E-Vehicles General Discussion
Topic: Want Go-kart motor & electronics recommendation
Replies: 7
Views: 1513

Re: Want Go-kart motor & electronics recommendation

https://www.electricmotorsport.com/emc-r-ls-me1004-pmdc-motor-24-48v-10-75-hp-cont-21-hp-pk.html I recommend brushed motors for simplicity and this motor is cheap and easy to control with right controller. Cheap, really? Are you saying nothing cheaper would be worth recommending for kids mucking ab...
by john61ct
Feb 23 2019 9:05am
Forum: Battery Technology
Topic: Panasonic NCR18650G - the mysterious 3600mAh battery's capacity test
Replies: 8
Views: 1300

Re: Panasonic NCR18650G - the mysterious 3600mAh battery's capacity test

And I see not available, at least not new from trusted sources?
by john61ct
Feb 21 2019 3:31pm
Forum: Battery Technology
Topic: Panasonic NCR18650G - the mysterious 3600mAh battery's capacity test
Replies: 8
Views: 1300

Re: Panasonic NCR18650G - the mysterious 3600mAh battery's capacity test

I am starting to get mildly interested in these little cylindricals, coming from an LFP prismatics background. What would it cost to get to say 100Ah @24-28V for just the cells? New and from a highly trusted source to avoid QA rejects of course. And very curious why these reviews never mention the s...
by john61ct
Feb 21 2019 1:07am
Forum: Battery Technology
Topic: Build your own charger
Replies: 153
Views: 15104

Re: Build your own charger

Yes, Elteks are very professionally designed telecom gear, designed to coordinate in parallel, not sure about series though. The enclosures can be a challenge to find, cost more than the rectifier inserts. And the model # nomenclature, hard to know what work together. The controller units not too pr...
by john61ct
Feb 19 2019 8:22pm
Forum: Battery Technology
Topic: Build your own charger
Replies: 153
Views: 15104

Re: Build your own charger

Hey I'm not saying it isn't fantastic, certainly ingenious and yes great value for money too if it turns out to be stable, reliable etc. Just saying my use case might require a different, yes likely more expensive approach. https://endless-sphere.com/forums/viewtopic.php?t=97807 https://endless-sphe...
by john61ct
Feb 19 2019 12:24pm
Forum: Battery Technology
Topic: Build your own charger
Replies: 153
Views: 15104

Re: Build your own charger

Wow that is certainly a stack.

Personally I'd pay quite a bit more for lighter, less space and fewer units.

But some modularity is great, to power off multiple circuits or gennies.

My goal is 3-4 kW @ 48-60V
by john61ct
Feb 16 2019 3:41pm
Forum: Battery Technology
Topic: Charge 6s tesla pack with computer PSU
Replies: 1
Views: 256

Re: Charge 6s tesla pack with computer PSU

wow cool kludges, hope you're being safe

aren't your PSUs CL'd by the solar controller?
by john61ct
Feb 16 2019 1:04pm
Forum: Battery Technology
Topic: 80% charge in one hour?
Replies: 27
Views: 1886

Re: 80% charge in one hour?

That's not only the result of corruption in government and industry-- it's the moral failure of a people who have decided that driving personal cars is acceptable no matter what damage it does. A lot of that moral failure is due to billions of dollars spent by FF on decades of skilled propaganda su...
by john61ct
Feb 14 2019 5:56pm
Forum: Battery Technology
Topic: 80% charge in one hour?
Replies: 27
Views: 1886

Re: 80% charge in one hour?

TS? Is that the OP? I think his statement of his (perceived) problem is perfectly clear, and the response are accurate and targeted toward clearing up his misunderstandings, with constructive suggestions for adjusting his expectations and behaviours so as not to cause other problems of which he seem...
by john61ct
Feb 14 2019 2:09pm
Forum: Battery Technology
Topic: DIY 14S10P lasercut full wooden enclosure/cell holder
Replies: 23
Views: 2350

Re: DIY 14S10P lasercut full wooden enclosure/cell holder

Wood will have some "give" compared to metal or most plastics. Foam board would be ideal.

I guess without that factor, the ideal would be the "top & bottom" hold the battery tight at the terminals, but holes allow a bit of play.
by john61ct
Feb 14 2019 1:41pm
Forum: Battery Technology
Topic: 80% charge in one hour?
Replies: 27
Views: 1886

Re: 80% charge in one hour?

LI of any chemistry will **accept** (pull, demand) a rate higher than is good for it wrt longevity. Up to you what you want the max rate to be allowed, "made available" by the charge source. From the batt health POV, no Absorb / CV stage at all is needed, can just charge **to** a terminati...
by john61ct
Feb 14 2019 8:15am
Forum: Battery Technology
Topic: 80% charge in one hour?
Replies: 27
Views: 1886

Re: 80% charge in one hour?

The key is defining YOUR version of 100%, not going by the absolute top voltage possible according to the batt maker who wants a short cycle life. Drop your Ah expectation a little, back the finish voltage down a lttle. Peace of mind, fast charge now possible, bank lasts much longer and really not g...