Innova 3721 Battery and Charging System Monitor

while you're waiting for innova tool to arrive, do these steps first: check your alternator drive belt for tension and condition. next, clean your battery posts shiny clean. check your negative battery cable has a good ground to motor or frame and it's clean and not all rusty or whatever. check your battery cells filling to proper level with distilled water if your battery is not gel sealed or similar. now you're set to plug in the tool. check voltage before starting with key on. to get an idea of what this tool can do for you, turn on a heater fan or something similar like parking lights. you will see voltage immediately drop. now, start the car/truck/mh or what have you. the voltage drops when starter cranks. so, now your motor is running. notice voltage rise to almost 14 volts or similar. this tells you alternator should be working fine. next time you drive your car, plug in tool. check voltage while driving if you wish. my neighbor borrowed mine and found his alternator was not working as expected. he promptly replaced his drive belt and cleaned all. i live in the northwest. our weather is worst for batteries. battery maintenance in northwest is almost a religion. anyway, buy this tool. it can save you an ugly headache of no start in grocery store parking lot. by the way, walmart installs new batteries and does so in a professional manner (we know and use walmart batteries) at no charge for install.