7.4V 5200mAh Battery Topcon BT-65Q for Topcon GTS-720 GTS-750 GTS-900 GPT-7500

Product Specification

7.4V 5200mAh Battery Topcon BT-65Q for Topcon GTS-720 GTS-750 GTS-900 GPT-7500 Total Station

Model: BT-65Q

Specifications:

Features:

• Equivalent to Topcon BT-65Q battery
• Rechargeable
• 7.4 Volts
• 5200 mAh capacity
• Compatible with Topcon GTS-900 and GPT-9000 total station.

Introduction:

For long-lasting power on the go, this Leosurvey Li Ion Battery is the ideal replacement for the Topcon BT-65Q battery. Works with Topcon GTS-900 and GPT-9000 total station, it is durable and lightweight for easy storage.

This rechargeable battery has an output voltage of 7.4V and 5200 mAh capacity. You can charge it using the Leosurvey BC-30 charger or BC-30D dual charger.

What will cause my battery to lose power?

A battery over time degrades and eventually stops working. In fact the battery from its very first charge begins a very slow process that causes the battery to cease from functioning. Collectively the process is called battery degradation and power loss and it includes the following: declining capacity, increasing internal resistance, elevated self-discharge, and premature voltage cut-off on discharge.

Declining capacity is when the amount of charge a battery can hold gradually decreases due to usage, aging, and with some chemistry, lack of maintenance.

The loss of charge acceptance of the Li ion/polymer batteries is due to cell oxidation. Cell oxidation is when the cells of the battery lose their electrons. This is a normal process of the battery charge creation process. The capacity loss is permanent because the metals used in the cells run for a specific time only and are being consumed during their service life.

Internal resistance, known as impedance, determines the performance and runtime of a battery. It is a measure of opposition to a sinusoidal electric current. A high internal resistance curtails the flow of energy from the battery to a device. The aging of the battery cells contributes, primarily, to the increase in resistance as does cell oxidation. Interestingly energy may still be present in the battery, but it can no longer be delivered due to poor conductivity.

Elevated Self-discharge: All batteries have an inherent self-discharge. The self-discharge on nickel-based batteries is 10 to 15 percent of its capacity in the first 24 hours after charge, followed by 10 to 15 percent every month thereafter. Li-ion batteries self-discharge about five percent in the first 24 hours and one to two percent thereafter in the following months of use. At higher temperatures, the self-discharge on all battery chemistries increases. The self-discharge of a battery increases with age and usage. Once a battery exhibits high self-discharge, little can be done to reverse the effect. Be sure never to leave a rechargeable battery at low charge for long periods, even during storage.

Premature Voltage Cut-Off: Some devices do not fully utilize the low-end voltage spectrum of a battery. A device may cut itself off before the designated end-of-discharge voltage is reached leaving battery power in the battery unused. For example, a pda that is powered with a single-cell Li ion battery and is designed to cut-off at 3.7V may actually cut-off at 3.3V. Obviously the full potential of the battery and the device is lost (not utilized). Why? It could be something with elevated internal resistance and or operations at warm ambient temperatures. Devices that load the battery with current bursts are more receptive to premature voltage cut-off than analog equipment. High cut-off voltage is mostly equipment related, not battery.