LT3652 battery balancing

Hello,

I designed the solar charger based on the LT3652. I designed the charger that can with the use of jumpers by switching resistor between Vbat and Vfb program the desired value of the battery voltage. I use combination for 2 or 3 cells of the LiFePO4 and LTO batteries. When I charge the batteries, the voltages of given cell is different, for example when I charge the 2cells of LTO, and program Vbat to 5.6V, one of them reach 2.9V, and other 2.7V.

Do you have any battery balancing circuit that is quite small and I can use it to balancing the battery voltages?