We are evaluating the LT8490 as the battery charge controller for a system which contains two 12-volt SLA batteries connected in series. Each battery is rated at 0.8AH and the maximum bulk charging current is 0.24 amps per the battery datasheet. Using the equations in the LT8490 datasheet we came up with the following changes for the DC2069A demo board. However, it did not work with these changes. Does the LT8490 support applications where charging current limit IOUT(MAX) is as low as .24 amps?

The following resistors were changed for the current limit:

R57 from 0.003Ω to .2Ω

R49 from 124kΩ to 75kΩ

R65 from 30.1kΩ to 36.5kΩ

The following resistor was changed for 24V battery:

R13 from 113kΩ to 226kΩ

hi,

there is a lot more changes needed for making a low power charger from the 16.7A 12V demo board.

I recommend that you read the datasheet in detail, and the FAQ. I also include a calculator for selecting resistor networks on input and output. you need to make resistor changes depending on panel and battery voltage. to only change R113 will not work.

I am travelling right now and do not have all documentation with me, but you could check out the design examples given in the portfolio pdf to get started. one limitation is that the input current limit cannot be set lower than 2A.

Tage