I am having problems as well with my DT800 and the internal battery supply. After Fully Charging the Battery the DT800 will only last for around 4-5 hours before voltage drops to below 9.5 V and the system goes to sleep.

The only program running is checking the internal battery voltage and Current once every 1 minute. Full Charge on the Battery reads 13.97V It appears to be drawing around 690 mA during this time.

Isn't DT800 internal "main" battery a 12 V battery, is it? Even without load the voltage of 13.97 V seems a bit high to me. How old is the internal battery? Are you sure it is ok? Do you have the same problems when you replace the internal battery?

Good morning dc2906,

DT800 is heavy on the power when compared to other dataTaker products. With the battery current if it is reading positive then the battery is being charged, if the number is negative then the battery is being discharged. As the reading is 690 mA then the battery is still being charged up. The current draw during charging can be up to 1 Amp and when fully charged will drop to a few mA.

It is normal for the fully charged Voltage to float up to around 14 Volts. Battery life will also depend on the age of the battery. The more charge cycles the shorter the the expected life.

Try fully charging the battery, setting the sleep mode and then run your testing again. You may want to consider replacing the internal battery especially if it is more than a few years old.

Cheers,
Roger

Roger,

The current DT800 was drawing was a negative number. The Battery is also only 3 months old. How long would you expect the internal battery to last before the DT800 will go to sleep?

If you need to run from an external battery what is the minimum size battery would you recommend

Good morning dc2906,

An IBAT of -690 mA seems to be excessive. When the logger is awake it will draw about 150 mA (the battery will take a about 400 mA when charging) so 700 mA would indicate there is probably some thing wrong with the logger.

I think you should discuss this with your dataTaker distributor and look at having the unit sent back for repair.

Note: For details on using sleep mode and current draw figures please refer to the DT800 user manual (Page 43).

Cheers,
Roger