Simple 4s lifepo4 12v block management

[juzamthai]

Hi

Living in an RV, battery system quality is biggest part of confort, for a geek like me.

So i decide to build up a little project.


I already found an easy way to convert 12v dc to 19v dc (for the laptop reloading)
Clear

So i dlike to go for a 4s lifepo4 pack.
Arround 100 A even more in 12v.

I'm thinking about winston or sinopoly or calb cells (all in 100A 3,2v)

These cells will discharge at max 3C
And for loading, 0.3c to 2c

What charger power size should i take for a 100ah 12v block.

And a kind of charger that can automaticaly cut off when the max treshold is reached.


I know that to optimise lifecycles, it's better to stop charging when reaching 3.65v /cell wich is enough and avoid all kind of "over-x" ^^

Also read that most of burst case happened because of defective bms.

And that it's safer to avoid using one.



So let me know your point of view about all this.

And if you have a automatic settable cutoff charger that will handle the 100A 12v as fast as possible.


Thank you for your help.

Regards.

 

[Sunder]

just get an adjustable switchmode psu set for 14.6v.

The faster you want to charge, the more of them you put in parallel. Easy.

 

[IBScootn]

Keep the charging current less than 1/3C. I had 60AH cells and wanted to charge them using level 2 chargers (30-32A), but distributors tech support said no more than 1/3C (or 20A in my case).

 

[juzamthai]

Ok

Got it for 1/3C reload (Or 33A in my case of 100 Ah

Means it will take between 2 and 3 hours to get fully charged.


For the PSU, do you have any ref to share, a 30 A modele that will automaticaly cutoff ?


Regards

 

[juzamthai]

hard to find a 12v 30 amp charger.

A 40 is really too much ?


Or can I use a 20 + a 10 at the same time in // ?
Or 3 x 10A ?

Or maybe I should go for 24v, I will find more big power charger model.

 

[Sunder]

You don't need an automatic cut off if the final voltage is below what the battery can take.

If power supply voltage = battery voltage, then no current flows.

 

[juzamthai]

So this modele will be good for 100ah 12v pack ?

https://www.ev-power.eu/_d4816.html