Battery Basics

        There are several types of battery used in R/C models. The ones used in model yachting are mainly NiMh and Life because of the high cell voltage (2 cells =7.4v) is not compatible with all receivers but I have covered Lipo as well.

I personally think the best way to look after your batteries is to invest in a good auto

charger. The cheaper chargers rely on a resistor to limit the current (as the battery voltage rises the charging current falls but never goes to zero) this can lead to overcharging if left on.

and because you have no indication of when the battery is fully charged it is often undercharged

both over and under charging affect battery life.

Here are some answers to common questions

What does NiMH stand for?

          The material is Nickel Metal Hydride (NiMH) which has many advantages over other battery construction materials.

What is meant by battery memory?

        Older generation and batteries (NiCad) were subject to a memory effect. This is when a battery must be fully drained before recharge or their capacity is reduced. In the new generation of NiMh batteries this effect is vastly reduced and so they can be recharged at anytime during usage cycle although a complete discharge occasionally may be advantageous.

What is the mAh rating mean?

       This is a rating of energy storage capacity mAh = “milli-ampere hours”. So if a battery with a 2000 mAh rating will have twice the capacity of a 1000 mAh rating. The 2000mAh means it should give 2A for an hour although as discussed in ' Capacity' this is very rarely so.

How many times can a NiMH battery be recharged?

      The number of times a battery can be recharged depends on how the battery is used and how it is charged.

NiMH battery can be charged and discharged a few hundred times, but whether that means 100 times or 800 times has a lot to          do with how it is treated.

Can I use a higher rated mAh battery (i.e. 1800mAh instead of 2000mAh)

      Yes, the mAh rating will give you longer run times between recharges. The higher rated mAh of a battery has no effect on the servos of winches it drives except for to run it for longer .

Why are AA and AAA rechargeable batteries rated at 1.2 volts and alkaline batteries rated at 1.5 volts?

       In the course of their discharge, alkaline batteries actually average about 1.2 volts. The main difference is that an alkaline battery starts at 1.5 volts and gradually slopes off to less than 1.0 volts. NiMH batteries stay at about 1.2 volts for almost 80% of their discharge cycle. When an alkaline battery reaches 50% capacity, it will be delivering a lower voltage than a NiMH battery.

Do NiMH batteries lose capacity over time?

       Yes, but again it depends on how the battery is treated treat it rough and it will lose more capacity.