Author Topic: looking for an 8S LiIon charger IC  (Read 970 times)

0 Members and 1 Guest are viewing this topic.

Offline TmaxElectronicsTopic starter

  • Regular Contributor
  • *
  • Posts: 55
  • Country: de
    • My random (and very empty) electronics blog
looking for an 8S LiIon charger IC
« on: September 11, 2019, 09:44:31 am »
Hello,

I have a new battery powered studio light project, which at the moment uses a 4S LiIon battery pack with integrated USB C charging. However i now have plans for a version with more capacity and a more efficient boost circuit (instead of going from 15V to 50V i would go from 30V to 50V) for which i would need an 8S battery pack.

I have already looked around for a suitable boost charger but was not able to find one :-// . I did think about using the same IC as the LED driver, as it has an accurate voltage limit feature, but it does not have input current limit.

Is there even an integrated solution for such a special case, or will i have to improvise something or potentially even ditch the integrated charger all together?
« Last Edit: September 11, 2019, 09:54:05 am by TmaxElectronics »
 

Offline jonpaul

  • Super Contributor
  • ***
  • Posts: 3656
  • Country: fr
  • Analog, magnetics, Power, HV, Audio, Cinema
    • IEEE Spectrum
Re: looking for an 8S LiIon charger IC
« Reply #1 on: September 11, 2019, 12:47:38 pm »
Hello, no idea what you mean by 4S or 8S.

Please be more specific the type, and capacity battery.

Many dedicated IC s exist for battery charging.

Do not use an LED drive, completely different.

You do not mention the power source, 240v mains?

Finally beware that lithium batteries are potentially dangerous and catch fire or even explode if improperly charged.

There is a safety, compliance and liability issue in such a project especially if intended for volume manufacture.

As the cinéma and still film portable lighting market is well developed, you should survive the available lights and battery packs and chargers already existing.

Just the rambling of an old retired EE!

Bon Chance

Jon
An Internet Dinosaur...
 

Offline martin1454

  • Regular Contributor
  • *
  • Posts: 95
  • Country: dk
Re: looking for an 8S LiIon charger IC
« Reply #2 on: September 11, 2019, 01:03:14 pm »
Hello, no idea what you mean by 4S or 8S.

4S or 8S is 4/8 battery cells in series,

so 4*3.7V and 8*3.7V
 
The following users thanked this post: TmaxElectronics

Offline todd_fuller

  • Contributor
  • Posts: 39
  • Country: us
Re: looking for an 8S LiIon charger IC
« Reply #3 on: September 11, 2019, 03:26:38 pm »
Not many out there that handle 8S standalone. LTC4162 is one.
 

Offline TmaxElectronicsTopic starter

  • Regular Contributor
  • *
  • Posts: 55
  • Country: de
    • My random (and very empty) electronics blog
Re: looking for an 8S LiIon charger IC
« Reply #4 on: September 12, 2019, 08:01:02 pm »
But the LTC4162 is only step down right?
The usb would be able to supply a maximum of 20V, so i would need a boosting charger.

I did however find the LT3796, a boost controller IC with  CC and CV output modes and input current limit. It is however not intended for charging LiIon cells. Would it be possible to modify it to do that? I would expect the charge termination to be the most difficult thing.
 

Offline jhpadjustable

  • Frequent Contributor
  • **
  • Posts: 295
  • Country: us
  • Salt 'n' pepper beard
Re: looking for an 8S LiIon charger IC
« Reply #5 on: September 13, 2019, 10:33:35 am »
Isn't charge termination exactly what the LT3796's ~VMODE pin does?
"There are more things in heaven and earth, Arduino, than are dreamt of in your philosophy."
 

Offline TmaxElectronicsTopic starter

  • Regular Contributor
  • *
  • Posts: 55
  • Country: de
    • My random (and very empty) electronics blog
Re: looking for an 8S LiIon charger IC
« Reply #6 on: September 16, 2019, 12:59:20 pm »
Is that pin not just pulled low once the voltage reaches the set threshold? That would skip the CC part of the charge curve.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf