Search found 556 matches

by john61ct
May 21 2019 5:50pm
Forum: Battery Technology
Topic: Charger strange behaviour (53.5V)
Replies: 11
Views: 179

Re: Charger strange behaviour (53.5V)

999zip999 wrote:What would be nice to know is the state of charge.
1. 4.15
2. 4.01
3. 4.20v
13. Xxx volt
13S pack, 53.5V just after charger shuts down, so not quite at rest?

4.12V right?

by john61ct
May 21 2019 5:47pm
Forum: Battery Technology
Topic: Charger strange behaviour (53.5V)
Replies: 11
Views: 179

Re: Charger strange behaviour (53.5V)

So it's not the charger that stops charging once the voltage of battery gets to a certain level, but it's actually chargers response to the BMS stopping the charging process. Did I get this right? There are many possible permutations. Personally I wouldn't pull the trigger until I learned exactly h...
by john61ct
May 21 2019 3:27pm
Forum: Items for Sale - New
Topic: N.E.S.E. the no solder module
Replies: 280
Views: 30770

Re: N.E.S.E. the no solder module

Fantastic contribution to the open-hardware maker's movement, on behalf of the community, thanks a lot!
by john61ct
May 21 2019 2:58pm
Forum: Battery Technology
Topic: Charger strange behaviour (53.5V)
Replies: 11
Views: 179

Re: Charger strange behaviour (53.5V)

I planned anyway to use m604 circuit to stop charging at 4.05V per cell (52.65V), then every week or so do the full charge. Interesting, have you got a link to a detailed datasheet? Good experience with the reliability / longevity of this board? Up to how many charging amps can it tolerate? Or does...
by john61ct
May 21 2019 1:12pm
Forum: Battery Technology
Topic: Charger strange behaviour (53.5V)
Replies: 11
Views: 179

Re: Charger strange behaviour (53.5V)

13 in series x4.2 is 54.6. Just under that is a bit better for longevity, but with such a low charge rate, just stopping at 4.2V is a good strategy, rather than holding Absorb / CV stage for too long. Voltage always drops once charge stops, perfectly normal. Put a slight low-amp load on the pack for...
by john61ct
May 20 2019 11:11pm
Forum: Battery Technology
Topic: Bosch Powerpack 400 Orientation
Replies: 1
Views: 102

Re: Bosch Powerpack 400 Orientation

10S not 8 to get to nominal 37V

4P so x 2900mA = 11.6Ah

10 groups of 4, aka 4P10S

40 total cells, 413Wh

Apparently NCR186650PF?
by john61ct
May 18 2019 5:13pm
Forum: Battery Technology
Topic: Spot Welder Power Cable Length
Replies: 19
Views: 323

Re: Spot Welder Power Cable Length

Looking to not require AC at all.

Current isn't an issue I think, DC genset at say 12kW?

DC TIG may well be fine for heavy stuff, but most times old school stick will do.

In this case I was thinking spot welding, do you think Kweld will do for thin sheet, say  .030 ?
by john61ct
May 18 2019 3:56pm
Forum: Battery Technology
Topic: Spot Welder Power Cable Length
Replies: 19
Views: 323

Re: Spot Welder Power Cable Length

I didn't know those latter types can run off off-grid low voltage DC?
by john61ct
May 18 2019 2:05pm
Forum: Battery Technology
Topic: Spot Welder Power Cable Length
Replies: 19
Views: 323

Re: Spot Welder Power Cable Length

What are other good options for off-grid use with no AC generator available?

Thinking maybe some unit could handle both these cylindrical batteries, and jobs like attaching thin sheet metal to steel or aluminum profile chassis framing?
by john61ct
May 17 2019 6:03pm
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 29
Views: 532

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

I agree it would be nice if that's how the world was
by john61ct
May 17 2019 12:00pm
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 29
Views: 532

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

My question is, for both batteries, charging around 0.7 to 1C from time to time is possible without damaging the battery ? There is no black and white definition of "damage". Sacrificing a certain percentage of lifetime cycles to get fast charging when you need it is perfectly valid. From the consu...
by john61ct
May 17 2019 11:53am
Forum: Battery Technology
Topic: Spot Welder Power Cable Length
Replies: 19
Views: 323

Re: Spot Welder Power Cable Length

There are alternators (DC output generator / chargers) that can switch over to field welding service when needed, no mains AC involved at all.

Not for this sort of service I guess, but just saying. . .
by john61ct
May 17 2019 9:42am
Forum: Battery Technology
Topic: Adjust voltage of IC GOGOGO 71.4V/5A charger
Replies: 11
Views: 254

Re: Adjust voltage of IC GOGOGO 71.4V/5A charger

Another approach with promise, tap into the USB type-C PD spec, let a small cell / pack plug into any decent charger, it requests what it wants. 25-35W is doable with OTS cheap components, but haven't yet seen a "spoofer" can request infinite-variable voltage, so far 5V 9V and 12V presets only. http...
by john61ct
May 17 2019 1:21am
Forum: Battery Technology
Topic: Adjust voltage of IC GOGOGO 71.4V/5A charger
Replies: 11
Views: 254

Re: Adjust voltage of IC GOGOGO 71.4V/5A charger

I do not need higher than 5V, could even settle for 3-5, just including LTO would be nice.

If not direct rectifier going that low, I'm thinking go with a 48V buss, the DCDC buck converters down to 5V are cheap as chips per 10-20A output, just makes for a bit of a project.
by john61ct
May 16 2019 11:18pm
Forum: Battery Technology
Topic: ULtra Compact 1800W charger + Eltek programming
Replies: 279
Views: 39496

Re: ULtra Compact 1800W charger + Eltek programming


J_haggerty wrote: If I can figure out how to upload a photo through my phone later I will.
Post to Imgur, helper apps abound.

Then link from your posts, per photo, or to a gallery.

Google Drive similar but not conducive to privacy if you haven't let go of that fantasy yet.

by john61ct
May 16 2019 10:16pm
Forum: Battery Technology
Topic: Solderless weldless 36V battery could do 200A
Replies: 47
Views: 1233

Re: Solderless weldless 36V battery could do 200A

Its not a bms, pcm, at least by my standards. I got that one cause its boxed and waterproof You say "that one", and I keep asking, "what one"? Please, can you link to it? > These boards do not protect the cells. They have 2-3 wire communication with master unit and drain resistor, maybe led. What n...
by john61ct
May 16 2019 8:52pm
Forum: Battery Technology
Topic: Adjust voltage of IC GOGOGO 71.4V/5A charger
Replies: 11
Views: 254

Re: Adjust voltage of IC GOGOGO 71.4V/5A charger

So what would you recommend as a cheap but good starting point for 2 - 5V?

Ideally 1000W range, but could make do with say 300 at a time if necessary?
by john61ct
May 16 2019 8:45pm
Forum: Battery Technology
Topic: Spot Welder Power Cable Length
Replies: 19
Views: 323

Re: Spot Welder Power Cable Length

And 10 gauge is not even what I'd call that thick.

Put in a 60' run of 4/0 (0000, 212 kcmil) boat wire, about a half-inch cross section just for the copper.

Wire alone cost $14 a foot, nearly a grand delivered.
by john61ct
May 16 2019 8:35pm
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 29
Views: 532

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

A123 26650 are LFP Totally different chemistry, fantastic longevity if treated well, should use a setpoint-adjustable charger and BMS. and great discharge rate when needed. But less energy dense, what is the use case? LPF has utter shit power density and are expensive per Wh. with current 18650 pri...
by john61ct
May 16 2019 10:37am
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 29
Views: 532

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

A123 26650 are LFP

Totally different chemistry, fantastic longevity if treated well, should use a setpoint-adjustable charger and BMS.

and great discharge rate when needed.

But less energy dense, what is the use case?

by john61ct
May 16 2019 10:17am
Forum: Battery Technology
Topic: A123 Pouch Cell Failure?
Replies: 12
Views: 292

Re: A123 Pouch Cell Failure?

https://endless-sphere.com/forums/viewtopic.php?t=98407 Plenty of hobby chargers have a controlled-current discharge testing function. Also, dedicated testers can be cheap, e.g SkyRC BD200 discharger, 200W and 30A also http://www.myrcmart.com/rcx-3in1-battery-balancer-discharger-voltage-indicator-15...
by john61ct
May 16 2019 9:51am
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 29
Views: 532

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E


Great pricing!

Is that a known good, trusted supplier, no factory seconds BS?

by john61ct
May 16 2019 9:41am
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 29
Views: 532

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

INR is NMC chemistry I believe LiNiMnCoO2

NCR is NCA chemistry, aka LiNiCoAlO2

some googling may explain relative power density / energy rates vs longevity advantages of each