My solar battery charger circuit based on LT3652 doesn't work well

[Taeyang]

I realized a solar battery charger circuit based on LT3652. Actually it doesn't work well, but I think I made some project error. In fact it doesn't reach the end of charge status. After read the datasheet of LT3652( http://www.kynix.com/uploadfiles/pdf...52EDD23PBF.pdf ), I need some theoretic suggestions.

Panel: Voc = 20V; Vp = 16.5V; P = 5W; Ip = 0.31A;

Battery: Lead-Acid; 12V; C = 4Ah;

The questions are:

What is the maximum charging current reachable? Icharge < Ipeak * (efficiency *Vpanel ) / Vbat is correct?

What happens if I set a charging current too high, for example 1A?

[Sunking]

I bet you are having all kinds of problems. To start you panel wattage is grossly undersized for your battery. A 5 watt panel at solar noon at best can only deliver .35 amps, so you can turn the current up as high as you want will not be enough. You need a 15 to 20 watt panel. 1 A i snot going to hurt that battery, but not possible with 5 watts. That would take 15 to 20 watts.