Why not design your own charger?

HKJ · 2019-11-05T10:42:46.000Z

tempo:

how fast can it discharge?

It will take years to discharge a cell on it, it is only a charger and as long as it is powered the leakage current is very low.

HKJ · 2019-11-05T10:52:33.000Z

cturtle:

How are you getting your graphs? Copy serial output to Excel?

With this software it is very easy to make these charts:

The chart can be saved in any size and will include the curves selected on the screen.

Mr.Poppy · 2019-11-05T21:57:09.000Z

group buy… in for 1 “HKJ Charger”

HKJ · 2019-11-06T11:02:01.000Z

Mr.Poppy:

group buy… in for 1 “HKJ Charger” :sunglasses:

I do not want to make any more chargers than I need, but if somebody want to arrange any group buy of parts or assembly service they are welcome.

If anybody want to play with the software it is here: Download of zip file

It includes the software and a couple of charge logfiles (CSV). All actual hardware control will be disabled, because no hardware is connected.
It is possible to look around in the software, load the logfile and play with the chart and table display.
It is the exact same version software that I use at the moment, I have neither added or removed anything for this demo version. I have tested that it starts on Windows and Linux.

To use/test it a working Java version 1.8 or newer must be installed.

HKJ · 2019-11-07T09:46:14.000Z

I modified the box to add the hole for the temperature sensor and change the led:

That is probably the final box.

The led required a bit of work, I could also have cut a track in the lid to get the led a bit closer to the surface, but decided not to.

kennybobby · 2019-11-07T12:15:00.000Z

Excellent work on your build and thank you for sharing the files. i really like how you integrated the LED in the cover.

Just wondering if you have ever had a cell swell up or explode while testing?

HKJ · 2019-11-07T12:21:01.000Z

kennybobby:

i really like how you integrated the LED in the cover.

With a 3d printer you have a lot of freedom when designing stuff.

kennybobby:

Just wondering if you have ever had a cell swell up or explode while testing?

No, I have had cells vent a couple of times, but that is rather undramatic, i.e. I usually never notice it before I remove the cell.

HKJ · 2019-11-17T10:52:57.000Z

Not much have happened with the charger.

I have mounted all the PCB’s, the one in the frame is still in the frame and working.

The software has got a few updates and I have made it more general. This means it can read any CSV file with a voltage and current column and show it, if the file include a timeStamp column counting seconds it can calculate capacity and energy if they are missing in the file. The software do not care if the file is from a charger or discharger, it will work with both.

The link in post #44 points to the updated software now.

HKJ · 2019-11-29T15:55:52.000Z

In my latest battery review: Test/review of Enerpower+ 18650 3000mAh (Gray) 2019
I uses this charger for a last minute test (Se bottom of review).

I needed a 4.35V charger and logging of the result, it was very easy to do.

HKJ · 2019-12-04T16:15:23.000Z

I am working on the article about the charger, but I do not know when I will be finished.

I did have time to a few software update, The IR curve can be calculated for any charge/discharge curve with pulsing current. The chart can either be saved to disk or copied to clipboard, both in a couple of resolutions.
Use the link in post #44 to get the software.

It is fairly easy for me to add support for other chargers/dischargers as long as they generate a CSV file. To get support email me a couple of CSV files together with a list of charger and software used and I will look at adding it. My email is info@_something_with_lygte

HKJ · 2020-01-05T17:29:46.000Z

Testing charge algorithm for LiFePO4 batteries with this charger: Charging LiFePO4 batteries, algorithms

AkosLukacs · 2020-01-30T13:39:26.000Z

Nice job.
How good is fasttech’s acrylic battery holder? Asking because on the last photos you used the aluminium battery holder.

HKJ · 2020-01-30T13:59:45.000Z

AkosLukacs:

How good is fasttech’s acrylic battery holder? Asking because on the last photos you used the aluminium battery holder.

The acrylic holder is generally fine, the issues I have:

It is slightly difficult to mount batteries in it, there is not enough space beside the battery for my fingers.
It will not fit 32xxx batteries
The front can melt when running hot.

Ad 3) I do still use them, but have replaced that piece of plastic with something that can handle high temperature. This means the inside of the battery connection piece sometimes melts and I have not found any place to buy spares, I do not believe the aluminium will handle this better.

AkosLukacs · 2020-01-30T15:19:01.000Z

Thanks.
Running too hot is something that happens at 5A or at 50A?

HKJ · 2020-01-30T15:34:05.000Z

AkosLukacs:

Thanks.
Running too hot is something that happens at 5A or at 50A?

Usually 20A or 30A, but only on a few batteries.

malkoff_junkie · 2020-02-05T17:40:53.000Z

so are you considering making a charger ?
I am looking at the Vapcell S4 or Dragon, but looking for something refreshingly new especially from HKJ!!!

JaredM · 2020-02-05T18:30:24.000Z

Definitely interested in trying to duplicate this. Super cool HKJ!! Thanks

HKJ · 2020-02-05T18:39:25.000Z

virencelights:

so are you considering making a charger ?

Not considering, I have been using it for some months now.
I will be publishing a the KiCad project file, i.e. schematic, gerbers etc…

But it is a single channel that can only be controlled from a computer and not very practical for everyday usage.

wle · 2020-02-05T18:42:27.000Z

i hope it defaults to something safe when windows reboots or whatever.

ideally it would remember where it was in the charge cycle and resume when the driver or app or whatever comes back

wle

HKJ · 2020-02-05T19:36:57.000Z

wle:

i hope it defaults to something safe when windows reboots or whatever.

ideally it would remember where it was in the charge cycle and resume when the driver or app or whatever comes back

wle

You start it from the computer and you can log from the computer, the charging is controlled locally by the charger. If it looses power or is reset it will always start in idle mode.
It is not a safe charger, you can ask it to do anything within its range. I.e. if you ask to charge a LiIon battery to 4.4V it will do it. It do have a safe LiIon and safe NiMH mode.