Continue to Site

# help with designs of lithium titanate battery charger. Max17703

Status
Not open for further replies.

#### nico05

##### New Member
Hi, so i'm designing a charger for lithium titanate bank, i have to give 8.4v(3 battery parallel banks in series, using 2.8 for charging each bank, 5x3).
So i'm calculating the resistors, caps, etc and in the max17703 data sheet (https://www.mouser.cl/ProductDetail...EpiMZZMutXGli8Ay4kK6SD7YYu%2BTeL%2BOHn4Bp3tE=) at the part that they calculate the charging current they have this formula:

in the typical application circuit, we have this:

and hence the problem. It's says 4.2v/10A, but when i do the calculus, i got for Ichg = 1.04A. I don't know if i'm doing something wrong, dont' understand something from datasheet or the datasheet is wrong.

I'm afraid if i have this calculus wrong, the one i use for my needed voltage would be wrong.

Rs is 0.005 ohms, Vout_ss is 4.2v, Vfb_reg is 1.25v, Rbot(R2) is 17.8 kilo ohms, Rtop(R1) is 42.2 kilo ohms, and Gv is 1.3

if some1 could help me i would apreciate it.

Since the 5 milli-ohm resistor develops the current sense voltage you just need to know what input this voltage feeds. If it is the b-e junction of a bjt then 10A would produce 0.5V and this will determine the onset of current limiting - 0.6V nominally.

Status
Not open for further replies.

Replies
4
Views
1K
Replies
13
Views
2K
Replies
4
Views
1K
Replies
6
Views
3K
Replies
6
Views
3K