Trickle charging

Trickle charging

Trickle charging, also called float charging, means charging a battery at a similar rate as it is self-discharging, thus maintaining a full capacity battery. Most rechargeable batteries, particularly nickel-cadmium batteries or nickel metal hydride batteries, have a moderate rate of self-discharge, meaning they gradually lose their charge even if they are not used in a device. One must be careful, however, that if a battery regulator is not employed, the charge rate isn't greater than the level of self-discharge, or overcharging and possible damage or leakage may occur.

For example, a 24 volt battery pack, comprising 12 2-volt flooded lead-acid cells, which has been deeply discharged, would normally be restored by a boost charge of approximately 2.4 volts per cell for a short time (perhaps around 72 hours). Once the collective cell voltage reaches a surface charge of 28.8 volts (2.4 volts x 12 cells), the charge rate would be switched to the sustained lower float-charging rate of typically 2.23 volts.

Eventually, with the Boost charge removed, the surface charge will diminish slightly and the battery-bank voltage will stabilise at a preset float voltage, in the case of the example above to approximately 27 volts (2.23 volts x 12).

Charging rates for a trickle charge are very low. For example, if the normal capacity of a battery is C (ampere-hours), the battery may be designed to be discharged at a rate of C/8 or an 8-hour rate. The recharge rate may be at the C/8 rate or as fast as C/2 for some types of battery. A float or trickle charge might be as low as C/300 ( a 300-hour discharge rate) to overcome the self-discharge. Allowable trickle charging rates must conform to the battery manufacturer's recommendations.

In low duty-cycle applications, where a relatively high current or power is required infrequently, charger costs can be minimized by applying trickle-charging principles. This can be an economy measure in cases where the charging method could be quite expensive if the full charging rate were employed, such as solar-cell installations. Full battery capacity can be achieved at a low charging current over a long period of time to provide a high-power load for a short period.

Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • trickle charge — A continuous charging of a storage battery at a low rate to keep it in a fully charged condition for a period when no current is drawn from it …   Dictionary of automotive terms

  • Battery charger — This unit charges the batteries until they reach a specific voltage and then it trickle charges the batteries until it is disconnected …   Wikipedia

  • Nickel–metal hydride battery — NiMH redirects here. For other uses, see NIMH (disambiguation). Nickel–metal hydride battery Modern, high capacity NiMH rechargeable cells specific energy 60–120 W·h/kg[1] …   Wikipedia

  • Nickel-metal hydride battery — Batteries caption=Modern, high capacity NiMH rechargeable batteries EtoW=30–80 Wh/kg EtoS=140–300 Wh/L PtoW=250–1000 W/kg CtoDE=66% [] EtoCP=2.75 Wh/US$ [ [ NiMH Battery… …   Wikipedia

  • Automotive battery — 12 V, 40 Ah Lead acid car battery An automotive battery is a type of rechargeable battery that supplies electric energy to an automobile.[1] Usually this refers to an SLI battery (starting, lighting, ignition) to power the starter motor …   Wikipedia

  • Car battery — A car battery is a type of rechargeable battery that supplies electric energy to an automobile [ Horst Bauer Bosch Automotive Handbook 4th Edition Robert Bosch GmbH, Stuttgart 1996 ISBN 0 8376 0333 1, pages 803 807 ] . Usually this refers to an… …   Wikipedia

  • Rechargeable battery — A rechargeable lithium polymer Nokia mobile phone battery …   Wikipedia

  • Battery (electricity) — For other uses, see Battery (disambiguation). Various cells and batteries (top left to bottom right): two AA, one D, one handheld ham radio battery, two 9 volt (PP3), two AAA, one C, one …   Wikipedia

  • Капельная подзарядка — (англ. trickle charging) подзарядка аккумулятора малым током, для компенсации саморазряда. Большинство аккумуляторов, в частности никель металл гидридные и никель кадмиевые имеют заметный саморазряд. Это значит, что они постепенно теряют… …   Википедия

  • Nickel–zinc battery — specific energy 100 W·h/kg energy density 280 W·h/L specific power > 900 W/kg Energy/consumer price 2–3Wh/US$ Cycle durability 400–1000[ …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”