6 volt lead acid battery tester for a bait boat

http://www.circuit-projects.com/battery/economic-battery-sufficiency-tester-by-bc547.html

Can this one be modified so 3 low power consumption
l.e.ds can be added, so they would show the state of a 6volt 4.2-4 amp lead acid battery, red for very low amber for low green for high, tried hobby shops, but they only have ready made testers with leds, which cant be modified so that I can have the leds coming out of the back of the boat, thanks for any help.

http://images.maplin.co.uk/full/l21ac.jpg battery


http://www.carpcatchers.biz/acatalog/Lakestar_Pocket_Rocket_Bait_Boat.html boat

Do you want the LEDs always on? Also are you more comfortable with an analog solution or a microcontroller solution?

I'm curious about this boat is it RC? And do you fish behind it?

You don't need 3 LEDs to indicate 3 states. You could make a very simple tester with a red and green LED, for example. Nothing lit means tester is disconnected or battery is very low. Green means it's at least above the minimum threshold and red+green means it's above the upper threshold. In normal operation, you want green on and red off.

Now you only have to light two LEDs, each with its own threshold. For something very quick and dirty, you could use a voltage divider and the B-E drop of a transistor as the voltage reference. For more precision and temperature stability, use TL431 instead of transistors.

I`m a complete novice, last time I did electronics was at 13 in school but I learn fast, maplins do a low consumption led, prefer them always on, that way I can see that its working even at distance on the water, red would be the lowest threshold, green highest amber in the middle, green goes out medium power, amber goes out low power, red , bring the boat in change the battery , I will take the boat apart and let you know what motors its running in a couple of hours, thanks for your replies so far

RC yes, you use it to put the bait at distances further than castable, upto 500yards

MFA como drills torpedo 500 4.5 - 15 volt dc motors