Serious battery charging station setups on a budget

Why don’t we pass around ideas for battery charging stations for those of us that have enough cells that a standard 4 cell charger doesn’t hack it.

Here is my battery station as it sits right now:

I have been using a hobby charger to charge my batteries since day one, partly because I already knew how to use them and partly because they are more powerful then the dedicated 18650 chargers for anything close to the same price point.

Well for some time I used the old classic Imax B6 charger but the calibration was always off a bit and they stupidly won’t let you recalibrate it after the first power on.

I then upgraded to a Turingy Accucell-6 charger, it has 6A of charger current for 5A for the B6 but mostly the calibration was closer (only about .01-.02 off instead of .05). It served me well but there were still little things about it that annoyed me.

Recently I was reading something about chargers and heard about some custom firmware for the Imax B6. Turns out it uses an ATmega MCU and can be flashed just like with do with the Attiny’s, same programmer ect. Just make sure you read the hardware section to ensure you have an ATmega version of the B6.

You can find the firmware here: GitHub - stawel/cheali-charger: cheap lipo charger

So I decided to give it a try, well I wish I had found it sooner! I am now using the Imax B6 as my primary charger once again, the features on this firmware are great, you can set everything exactly how you want it to be and it is DEAD ON accurate, like down to the .001 level vs my UT139C.

The single best feature though is that you can use the balance ports for voltage detection when charging. Usually you lose a fair amount of voltage in the wires and this means the charger thinks it is imputing a higher voltage to the batteries then it actually is. Thus it will think it needs to reduce current before it actually does, extending charge times.

By taking the voltage reading with the balance port it sees the actual voltage and thus sends the full current the battery can accept. This greatly reduces charge time and accuracy! It also allows for much better internal resistance and even wire resistance tests along with a ton of other features.

So if you are looking for a cheap charger that will handle lots of current/batteries, look into a $15 imax B6 with custom firmware

Now for the rest of my charging station setup.

You will notices the charging banks for 14x 18650’s at a time, 4x 26650’s, 2x 18350 and 4x 14500. I have a 2 wire voltmemter from RMM mounted on the 18650 and 26650 to allow for quick voltage checks of batteries and to see the exact voltage while charging. If you calibrate those little meters they are surprisingly accurate.

I love having the large charging banks because as you can see I have lots of backup batteries. I simply swap out batteries in lights until I have a full “load” and charge them all at once. It takes awhile but frankly I am in no hurry, I figure I abuse them enough during discharge, so a slow charge is a good thing.

Naturally you can load up as few batteries as you want and charge them at up to 5A.

This is a great way to charge a lot of batteries easily.

Next you will notice the 3D printed battery holders, these are great for keeping the batteries organized and ready for use.

Each 18650 tray holds 60 batteries in this case but can be made to any size you want basically if your printer is large enough. I like having them in sets of 6 per row as for laptop pulls you generally get 6 cells. I then use a few from a set in a light and the fully charged ones stay on the left hand side, the discharged ones stay on the right hand side. When they are all on the right side it is time to recharge the batch.

Thats it for my basic charging station. Although when I am in a real hurry to charge something I bring the battery bank over to this 12A power supply where I can charge it fully loaded with 14 cells with almost 1A per cell (they have a 15A power supply now that could do more).

I reviewed these here: Review of DP50V5A & DPS3012 bench top power supply modules, best bang for the buck around!

I also have a simple nitecore USB charger that I keep around for times when I just want to charge a single battery for some reason.

Can you post links to the custom firmware for the IMAX B6? A google search pulls up this page: Martin Melchior's homepage: (re)Calibrating the IMAX B6 AC charger Is this where you got your information?

Opp’s, I had the link copied but forgot to paste it into the OP lol. Added it now.

I have had my eyes on balancing charger for a while, you made me pull the trigger. Can you link to where you got yours for $15? I’m afraid those on ebay are clones. Btw, you have been giving us some amazing content here lately, thanks!

EDIT: Clones are also supported by custom fw, so $15 ones on ebay are fine, I guess. Do you know if yours spits out serial data on temperature probe connector?

I have lived with a Nitecore UM20 and an Xtar Vp2 for 2 years now, but I was planning on getting a Liitokala lii-500 very soon so I can do 4 at once at a decent speed. I don’t get very in depth with my charging or cell testing, I just need something reasonably accurate and reliable that charges 4 cells at at least 1 amp each, and it would be nice if I could charge different cell sizes at the same time.

So, what are the benefits to doing it your way vs the Liitokala?

The main benefit I see up front is a slight cost. The B6 is $15 +$3 battery holder. The 500 is about $22.

The main drawback I see is that the 500 is once nice package with a single power cord that is easy to travel. The B6 I would need more of a whole station like you have in your picture.

This is the one I ordered HTRC IMAX B6 Digital LCD RC Lipo Life Battery Balance Charger for sale online | eBay

I expected a clone but apparently it was an original from the internal layout? Either way it works great, but then I did order it over a year ago so I am sure a different batch.

Thanks for the support, trying to give back a little after learning so much myself from others hard work.

BTW, don’t worry about actually using the balancing ports, it is FAR better to charge the cells in parallel and that doesn’t need balancing.

I guess I’ll ask sellers what MCU is inside. I’ve had luck before with questions like this, they apparently know what they are selling.
Well I’m gonna do it your way, paralel! :smiley:

If you only need 4 ports to charge at a time, then a pre-made unit is most likely for you unless you really want full control over all the options ect.

There is nothing “wrong” with the pre-made units but once you start charging a LOT of batteries they are inconvenient and expensive. Not to mention a LOT more hassle.

You can try that although I would not hold my breath on getting an answer.

I am pretty sure that all the “50w” rated models are the ATmega, pretty sure it is just the higher rated units that are something else. That is only for a little reading though, it could be otherwise.

I tried doing them in series and using the balancing ports at first. I will say that the constant current part of the charge can go faster this way since it can output more total wattage this way.

Once it gets to the constant voltage stage though things slow WAY WAY down as it has to charge for a little bit, then dischagre the overcharged cells, and repeat the process over and over.

In parallel it sees all the cells as one giant battery and it takes the slow and steady approach by comparison.

The only thing with parallel charging is to make sure the cells are within ~.3-.5 volts before connecting them together and then let them “balance” for a little bit before starting the charge cycle.

Very cool thread. I’ve been using an Accucel 6 for forever. Mine has no internal resistance measuring. If I go with the B6 and the FW upgrade, I can measure internal resistance with it? Awesome.

If yes, will you please point me to the FW update? Your link goes to all his/her FW’s.

EDIT: I think I see how it’s organized. I’ll read his tutorials and such this weekend. Looks a little different than just flashing a hex file or compiling a C file.

Correct, if you use the balance leads on cell 1 (he tells you how in the voltage calibration section) it will measure both the wire resistance (which is surprisingly high) and the cell resistance.

The link I posted in the OP is to the tutorial and should get you started, not real complicated, just basically making you you have the correct version to be flashed and then how to do it. It is aimed at novices, if you have already flashed drivers most of it you will already know.

All you really need is the Hex file from here for your model: cheali-charger/hex at master · stawel/cheali-charger · GitHub

Then wire up the pins to actually connect the programmer and program. The link someone posted earlier in here shows the way I connected the pins without soldering them. Not super reliable but it worked.

Thanks Texas_Ace. I ordered a charger from you link above. Also downloaded the applicable sounding hex file. Hoping to be able to get more consistent internal resistance readings then I get from the 2 different charges I use for that. Even when I try to minimize contact resistance issues, the results are still range a good bit.

I have had pretty good luck so far with the resistance readings (they are automatically taken when charging BTW, took me a bit to figure that out, scroll through the menus while charging to find them, they take a few seconds to get a good reading).

So far they have come out quite consistent with all my HE2’s of the same batch reading between 54-58, 30Q’s from banggood reading about 55-60 and GA’s reading about 80-85. Basically right in line with what I see them putting out in lights.

How those numbers compare with others readings I am not sure and honestly don’t care a ton as there are a lot of ways to calculate it. Most important for me is that every time I stick a battery in the charger it reads basically the same (naturally the actual IR varies a bit depending on charge ect).

For the one I got from that seller I used the ImaxB6 original 2.00 Atmega firmware, along with the original pinout on the programming port. Worked great for me but no idea if your’s will be from the same batch/the same internal board.

I have 30qs from gearbest. They measure 27mΩ ir on my mc3000 so 60 seems pretty high for the 30q. However, out of 40 batteries (30q) ordered at the same time, five of them measure around 40. the performance from cell to cell seems to very more than I am used to as well. Idk… That’s off topic though, sorry- :innocent:

Yeah, like I said there are lots of way to calculate the internal resistance, all returning slightly different numbers.

This is why consistency is more important then accuracy. As long as it reads the same every time you can compare batteries.

Ok. I see what you mean. I wasn’t aware of the discrepancies between measuring equipment.

That is a great set up, I do not understand why others are not more interested in what powers their flashlights.

OM! I can’t imagine how serious you guys are about this! Not even remotely!

I’m just a user of your distilled down knowledge and experience. I need to show my wife this thread to put into perspective for her that I’m the least of the “nuts”. Please excuse that, but that’s what she thinks I’ve become… a flashlight “nut”. As I get older I really appreciate lumens. She hasn’t a clue because as she stays inside it’s up to me to do the nightly chores. She still thinks I’m superman I suppose, but I know better and I like lumens.

lol, you think those pics are nuts, you should have seen when I had over 150 HE2’s laying around + another few dozen other high drain cells when I was hunting for my favorite cells.