Charger circuit questions

[eccerr0r]

Re: Charger circuit questions

DGW has a "5000mAh" 18650!

[Retro-Hipster]

Re: Charger circuit questions

Wow, I was so wrong with what was on the circuit board... that was embarrassing. Ahahahaha There isn't even a second chip on the board! Just half-bridge rectification, some support components to clamp the supply voltage and then a purpose made chip. >.<;;;

Based on the datasheet this is just not programmable at all sir. You would be much better off just getting a new thing.. :x And yes, DGW has many rediculous batteries. haha He also made videos about how ridiculous they are. The 5000mAh one weighed like 1/2 the weight of a 1200mAh battery. :'D

[eccerr0r]

Re: Charger circuit questions

Still looking for takers on someone who thinks it can be adjusted by adding "a few" components and that lying to the chip is easy...

It's tougher than I thought and I thought it was tough to begin with! What made me change my mind and increase complexity more?

Dealing with automatic polarity!

Remember to deal with this too! (though forcing the user to ensure the battery is inserted in only one polarity direction would simplify the circuitry a bit...)

[sam_sam_sam]

Re: Charger circuit questions

DGW has a "5000mAh" 18650!

Has anyone bought and tested this battery to see if their claims are true or not

Does anyone really believe that crap I do not

You be lucky to find brand name batteries that are 3200 milliamperes

[eccerr0r]

Re: Charger circuit questions

Well people have bought them, and people tested them (and found they are not real).
Just strange that DGW was still using it, perhaps just because it's expendable...

Then again even if expendable, if it immolates, it still immolates!!!

[Retro-Hipster]

Re: Charger circuit questions

AH, actually, DGW purched a lot of different obviously fake batteries like that one and did a full load test and such. Many of them came out closer to 500mAh than 5000. He definitely knows that they are crap.. I think he just likes things that are dangerous. :'D Dude made a damn x-ray machine in a yellow parts bin... you know he has to be crazy.


You should check out his videos on the subject Sam. It's both entertaining and insightful.

[eccerr0r]

Re: Charger circuit questions

I really should figure out a way to test the li-ion cells that I have for capacity and use that info to balance...

[sam_sam_sam]

Re: Charger circuit questions

I also need to come up with a plan to do the same thing

But my problem is finding time to devote to this type of project where I do not have distractions from work and elsewhere maybe after the first of the year It might slow down some

[Curious.George]

Re: Charger circuit questions

I also need to come up with a plan to do the same thing

But my problem is finding time to devote to this type of project where I do not have distractions from work and elsewhere maybe after the first of the year It might slow down some

ROTFLMFAO! There's a point (in life) when you realize there simply aren't enough hours to do ALL the things you WANT to do. Then, you decide what you can afford to "hire out" (or, "buy new") in order to free up some hours to do the things that you REALLY want to do! E.g., do I REALLY want to fix this little scooter and then try to find a home for it? Or, would I rather just SCRAP it and spend that time working on something else?

(Hint: if you've got a backlog of "stuff to do", it's only going to get LONGER!)

<frown>

[Retro-Hipster]

Re: Charger circuit questions

ROTFLMFAO! There's a point (in life) when you realize there simply aren't enough hours to do ALL the things you WANT to do. Then, you decide what you can afford to "hire out" (or, "buy new") in order to free up some hours to do the things that you REALLY want to do! E.g., do I REALLY want to fix this little scooter and then try to find a home for it? Or, would I rather just SCRAP it and spend that time working on something else?

(Hint: if you've got a backlog of "stuff to do", it's only going to get LONGER!)

<frown>

I could send you guys a simple Arduino load tester/schematic/spreadsheet I made a while back for testing batteries. Basically, it's basically just two voltage dividers and a current sense resistor. One divider reads the voltage before the current sense resistor to get the voltage of the power source (battery) and the other measures the voltage drop over the current sense resistor. There is a terminal for the battery input and then another terminal for output. The output can really be any resistive load, like an appropriately rated resistor.

The programming on the Arduino is super simple and just does the ohms law calculations and outputs the data in a csv file format in the terminal output.. (Also includes elapsed seconds) I use putty to connect and then tell putty to log the data. From there you can just import it into the spreadsheet program of your choice and graph it/do your calculations. (I could also send the spreadsheet.)

Actually, how about I make an article with all of this and send you both that. (I have a website I made for this sort of thing, but have basically not updated it at all since I made it. ahahah)

[eccerr0r]

Re: Charger circuit questions

designing the circuit is easy, actually getting hardware that actually does it, however, requires some physical effort...

[Curious.George]

Re: Charger circuit questions

I could send you guys a simple Arduino load tester/schematic/spreadsheet I made a while back for testing batteries.

My system for testing "batteries" is pretty simple:
- place in charger
- if charger indicates FAULT, "discard"
- else wait for charge cycle to complete
- use "charged" battery; if performance is less than desired, "discard"
- when supply of rechargeable batteries is exhausted, buy more.

I use this strategy for my NiMH, Li and SLA battery supplies. Note that the latter can get very expensive (e.g., 35AHr case sizes and larger); it's still not worth the time (for me) to tinker with them!

[Retro-Hipster]

Re: Charger circuit questions

My system for testing "batteries" is pretty simple:
- place in charger
- if charger indicates FAULT, "discard"
- else wait for charge cycle to complete
- use "charged" battery; if performance is less than desired, "discard"
- when supply of rechargeable batteries is exhausted, buy more.

I use this strategy for my NiMH, Li and SLA battery supplies. Note that the latter can get very expensive (e.g., 35AHr case sizes and larger); it's still not worth the time (for me) to tinker with them!

Oh, I totally made this because I'm the type that like.. buys batteries in bulk for a lot of things and liked testing stuff. I wanted to see how good the top 5 AA's were on amazon before I purchased the larger quantities... That, and this little thing is pretty handy for other things, like monitoring how much power a circuit uses over a long time period. (I used it to test a motion-activated cellular device over a month to see about how much power was consumed.)

[Curious.George]

Re: Charger circuit questions

Oh, I totally made this because I'm the type that like.. buys batteries in bulk for a lot of things and liked testing stuff.

If you learn something from the effort, great! E.g., you could note how the performance of the cells varies with load current (C, C/5, C/10, shelf-life). Or, how charge times varies based on charging current and/or strategy (there's boatloads of BFM in battery chemistries!)

[There have been a bunch of novel chargers designed over the years that used various "tricks" to speed up charging -- like "burping" the cells -- or minimize the aging the cells experience from the charging (and subsequent discharging).]

When I was younger, I designed car ignition systems, electronic thermostats, home alarm systems, MPPT controllers, etc. -- all "one-offs" (i.e., hobbyist, outside of my $WORK cuz they had their own ideas as to where my design efforts should be spent). If I wanted to learn something, I had to invent my own projects from which to learn.

But, the nature of the "challenges" increases as you get more experience (age). And, the time required to tackle those challenges increases dramatically -- weekend projects get replaced by projects that take months and even years to implement. (10 years -- full time -- for current project!)

[At the same time, you usually have other responsibilities that weren't on your ToDo list when younger (home maintenance, family, health) so the amount of time that you have available shrinks]

So, you learn to cut out the "small stuff" that you COULD do (if you had all the time in the world!) and spend money to buy those "solutions" so you have time to work on the "bigger (and more interesting) things".

E.g., I'll do an oil change cuz I can do it in the time it would take me to drive the car "someplace" and wait for "someone" to do it for me. Ditto replacing a starter. But, bodywork? Out of the question! Recap a generic motherboard? Nope; just rescue another machine that's already running!

Similarly, I'll design an operating system ONLY if I can't find something currently available that has the features that I need -- cuz the time spent designing and writing it could have been spent working on the actual application!