DK35 dash indicator light flashing

[double hunter]

New to me DK35,,got on it yesterday and all the dash indicator lights started flashing,,at idle they are just on but when I start using it and increase the rpm's they start flashing,,just a steady flashing,,every thing is working ok,,all the lights flash except the oil pressure light and it is working properly,,the only thing I have noticed is the battery seems like it might be a little week,,as I said it is new to me and havent had it but about a week,,any ideas, I dont have an owners manual,,thanks in advance