der_fisherman

Trickle charging should be set to maintain the charge, not add to it. As someone else mentioned, its generally around 1 to 2 % of the capacity. If the trickle charge is set too high, a lead acid battery will start to gas.....no matter what type of lead acid it is, this should be avoided. In fact, it is better if the trickle charge is set too low and the battery loses a little of its charge..... Trickle and normal charging are also affected by the temperature of the battery, a higher temp indicates that a smaller charge should be used.... Its also affected by the style and age of the battery, the older a battery gets, the higher the charge needed to maintain the charge..... With Gel batteries, one should follow all of the manufacturers recommendations to the letter, so I will ignore them completely here. The best trickle charge is the level at which the battery voltage does not increase or drop its voltage, it is just maintained exactly. I set to 13.2 volts. As the battery gets older, a year later for example, that charge will allow the battery to very slowly discharge only...not a bad thing. You could do a tiny readjust to get it back to maintaining the charge if that was important for the application. I only charge my batteries to 13.2 volts as I don't want any gassing, and I want my battery to have the best life possible, but this means that the battery only has about 70% of the maximum charge possible by "over charging"..... Letting a car battery discharge below 12.6 volts, starts to shorten its life. If you need to have a battery deep discharge proof, it must be a Leisure battery type, more expensive and not as good at delivering the amps needed to start a car engine for example, but it will accept deep discharging without any problems.... I personally would never recommend a car battery for anything other than a car, they are cheap, but deep discharge once and the battery is at least mortally wounded, do it a second time and it will be dead...... Always download the manufacturers info's and follow them slavishly as well....

I am relatively new to Stepper Motors myself, but depending upon how many motors you are planning to drive (my CNC router has 3 motors), you will need a power supply that can supply more than needed. I recently built a 24 volt 10 amp supply using a design from the Elektor magazine. It has proved to be exactly what I needed. Its a switched mode supply with about 85% efficiency, so it basically only takes what it needs from the mains.... The design was originally for a HiFi system, so it is very stable indeed, probably better than any stepper motor needs!! The output voltage is programmable with 4 resistors to any output voltage up to 40 volts.....it uses a toroidal transformer, so it also radiates very little energy to interfere with any other electronics.... The PCB is also available still from Elektor's European Supplier and probably whoever supplies them in the USA, or you could make your own. Use the data sheets for the chip used to calculate the required "program" resistors for the voltage you require.....as the supply is programed for 17 volts in the article.... If you need any assistance, just ask me and I will do my best for you or anyone else, but its mostly self explanatory....... Best wishes der fisherman e033054.pdf 1074fd.pdf