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SmartCharger - MARKET SURVEY, please answer

Hi dear builders,

I’d like to present you a project that took me few weeks of work.

The SmartCharger

Origin

The project came from few statements :

  1. On events we have all our own charger leading to a messy charge area and a car full of different chargers
  2. We barely can’t borrow a charger to someone due to the difference of voltage/current/connector
  3. Having different boards at home means differents chargers (6S, 10S, 12S). Money and mess.
  4. I can’t put pack into storage mode like I could with my lipo charger.

Features

  • 1 to 12S packs (with BMS)
  • Up to 15A
  • Storage mode charging (no discharging)
  • User friendly menu
  • Profiles (up to 5)
  • USB port for remote/smartphone charging
  • Safety features for battery, charger ans power supply protection
  • Charge current ramp up
  • Buzzer warning
  • Quiet ! (Fans running only if the SmartCharger gets warm)
  • Web server for remote monitoring, settings and control (using Wifi)
  • FW update OTA (using Wifi)

Overview


(First video I do in english… Sorry :grimacing: )

Feedbacks

I use this charger almost everyday and I could push it near the limits (420W over 440W) flawlessly.
I tested it with 10S and 12S li-ion battery.
Some friends used it and found it pretty intuitive.

What’s next ?

First, I want to collect your thoughts, comments and maybe features requests.
The housing and very basic code (including DPS comm library) are already published but I’m still wondering how I want this project to be directed.

Credits

@janpom 's DAVEGA project has been an great inspiration all along of the dev process.
Thousands thanks to him !
@Slak who helpt me when stucked with code issues
John, a web designer friend for the web app design

58 Likes

Great contribution. You tha man.

5 Likes

Some French power over there😍

6 Likes

This category definitely needs great innovation like this. Well done!

9 Likes

This is epic, grats on an incredible idea seen through to completion.

7 Likes

Awesome! would be great to have since I have one10s and one 12s board and I often want to put them in storage mode but cant really do it efficiently. Plus the monitoring feature is a great idea aswell!

2 Likes

Oh yes. This. So much this. Bring it on @Pimousse !!!

4 Likes

Big UP Mr P :stuck_out_tongue_winking_eye: :+1: !!!

2 Likes

Exactly what I am in search of! Definitely following this project.

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Thanks Pimousse !
One charger to rule them all :wink:
edit: realise it was the title of your topics…; excellent !!! :joy::joy::joy:

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Since most lithium ion chargers do the p group balancing at the end of the charge cycle, do you foresee any problems with ending the charge early?

What rate does the USB charge port charge at?

Last question for now, why the need for 2 setting control options? It seems you can change the values on the screen or the DPS. Are there options on the screen that can’t be changed on the DPS? This was the only part that confused me.

Sorry for all the questions! I am very interested haha.

3 Likes

Sorry for being a party pooper, but why do you need a web server on a charger? :laughing: Can’t you just use the connection between your phone and the ESC for monitoring? I don’t want someone to DDOS my charger and burn my house down lol

2 Likes

My charging setups are similar but much dumber :slight_smile: and I can totally see where this is useful.

  • presets for 10s, 12s, 13s (oops no 13s), 100%, 90%, 85%, 60%.
  • graph of charge, stats of charge (wh in, how long did it take)
  • history of charges, maybe saving named boards for this purpose

The built in display and control surface would be the preferred interface though.

3 Likes

Thanks for your interest !

CCCV chargers have nothing to do with balancing. They just supply energy.
The balancing algorithm is on the BMS side.
But this is a good point though !
Actually, If “early” means 4.10V instead of 4.20V, if think most of the BMS will have started balacing.
But for the storage mode (ie. around 3.85V) maybe the balance threshold isn’t triggered.

I chose to recycle an old smartphone charger rated to 1A to keep it small and reduce the footprint in the casing (and because 1A is fair enough for most for remote lipos).


The USB port supplies the power for ESP32 and OLED screen as well.
It wasn’t planned at the begginning.
I thought the DPS could supply 3.3V to all my stuffs but the manufacturer told me not to suck more than 50mA… Far to be enough. :pensive:

Because I thought it was eaiser to switch from Storage to Full instead of changing the end voltage settings.

No, everything can be done on the DPS.
Doing the settings through the OLED screen is a bit more convenient as you only have to specify S number. :slightly_smiling_face:

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I personnaly don’t have my ESCs powered while charging (as you may have seen in the video).

The BMS is still there !
In case of over/under voltage, charge is shut off.

I know a guy who buy a board ready-to-ride and got a 13S charger with his 12S board.
He figured it out when the battery died (after like dozens of charge), but it never caught fire (but died rapidly though).
BTW, I really agree with the security of the web app. Will think about it.
The web app is quite useful for updating the charger and keep monitoring the charge while seating in your sofa. :smile:

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Thank you for the clear and quick response!

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ha, this is nearly the exact same setup i have, except way more jenky and without all the smart features.

if you’re using dps5015, it doesn’t work fully for 12s because cutoff is 50.4v, and this dps unit only goes up to 50v. unless you’ve hacked it somehow.

i noticed bms balancing doesn’t kick in until 4.2v. in fact, you need to supply about 0.2v ABOVE cutoff voltage for the bleed resistors to get hot. so, for 10s - 42.2v, 12s - 50.6v

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This is shitty !
I only have configurable BMS so for me balancing works fine.
Didn’t know about other BMS ! I need to investigate a bit more. Thanks for the hint !

Yep I know. 50V leads to 4.167V/cell for 12S packs.
But there are no DPS8015.
For me, this isn’t really a concern as I think that going 0.033V per cell higher won’t add a huge amount of energy in the pack (personnaly I charge to 4.10V/cell).

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what configurable bms are you using? is it the smart bms?

the bestech bms that i’ve been using for the longest time are proving to be completely unreliable now.

and yea, they do have a dps8005, but it only does 5A.

someone wrote replacement firmware for the dps series and it’s open source so i bet you can tweak the voltage limits but…haven’t tried it…

1 Like

I looked closely at this Open source project, but this is over my knowledge.
For sure, I’d love to embed all my features directly into the DPS memory. Maybe one day…

One with bluetooth (don’t remember the brand) in one bord and the DieBieMS in another one.

Anyway, I looked closely to BMS specs.
Here are the ones for Battery support BMS :
balancing_bms_batterysupport

So I think your BMS is shitty. Hopefully, this behavior doesn’t apply to every BMS.

1 Like