Red Box International Battery Packs

General

Red Box battery packs are extremely rugged, have very low internal resistance and so produce very high power. They are especially portable in that they can be moved around without difficulty and can be used in any orientation, even inverted. They do not need cycling and therefore can be recharged at any time. Full charge is indicated by 26.0 volts on the built in voltmeter and fully discharged is indicated by 24.0 volts on the voltmeter.

Battery Operational Life

Battery life is cycle and discharge dependant. This means that the more cycles the batteries are subjected to and the greater the depth of discharge in each cycle, the more the battery plates are stressed and the faster they wear out. The worst case is therefore when the batteries are discharged repeatedly from full charge to fully discharged. In this type of usage the batteries may only last 200 cycles but, if only a small amount of capacity is used each time, before recharging, then up to 2000 cycles may be expected. Correct charging, float charging and the regularity of charging will also have an effect on battery life. It is most important to recharge the batteries as soon as possible after use to prevent the onset of sulfating of the plates. This condition will have an adverse effect upon the battery life and performance. It is also very important not to allow the batteries to become deep discharged, that is, discharged below 22.0 volts. If this occurs it will effect the battery life and it could result in the battery being very difficult, if not impossible, to recover to normal use. Generally, it is good practice to leave the power unit on the charger for as long, and as often as possible and it is recommended that when possible they should be left on for 24 hours every 2 weeks or so, to allow full cell equilibrium to be achieved.

There is therefore no specific formula to calculate actual battery life but, Red Box International Limited has some experience, based upon the time from sale of some power units to the time that they were returned for new cells to be fitted. A rough rule of thumb suggests that the approximate average life of these examples is around two years. Some units may be less and some considerably more.

Battery Capacity versus Voltage Drop

One may think that two battery power packs of the same voltage, but with different capacities, would have the same voltage drop when put under the same load. Not true. The battery with the larger capacity will have a lower voltage drop due to having a larger plate surface area. Because the load is spread over a larger plate area the chemistry is less affected. Therefore when you need greater performance, always choose a unit with the highest capacity.

Battery Temperature

All batteries suffer from cold temperature. This is particularly true if the battery is allowed to become cold soaked. That is, if the cold is allowed to reach the core of the battery. In Red Box power packs this condition may take some time to occur. Also, it is worth noting that, if this cold soaked condition is achieved then it will take a similar time to recover the battery to full performance, when it is placed in a warm atmosphere. It is therefore important to manage the portable packs and whenever possible, to keep or store them in as warm an environment as possible. It is important to fit the thermal covers and to avoid wind chill. These actions will delay cold soaking. The "High Tech" lead acid batteries used in Red Box power units will be less affected by cold than most aircraft batteries but even these batteries will eventually suffer if the cold problem is not managed.

Storage

The Red Box power units are maintenance free with regard to electrolyte replenishment. Maximum storage life, between charges, is 2 years at 25°C. (Less period at higher temperatures). Total storage life is 15 years (not affected by humidity).

© Red Box International Ltd 2003.