Battery replacement frequency is primarily determined by the type of use of the recorder. If the recorder is used as a fault finding tool and is only connected to a power source during an investigation (less than 50% of the time) then it is recommended that the battery be replaced with a good quality battery once every 3 months.
If the recorder is permanently installed as a voltage and current recorder, then the battery can be replaced, purely as a precaution, once a year. Again, a good quality battery should be used.
Doing a download (especially if extensive) without power connected i.e. using battery power, will drastically reduce the battery life. Up to 50mA of current is used during a download. The battery can supply this current for a total of 4 hours before reaching the 7.2V cutoff. This means 1% of battery life is used for every 3 minutes of download.
To combat this, it is suggested connecting one of the voltage channels to the mains and then download. Care should be exercised to not cause multiple events to occur while connecting. This can easily happen by putting a live cable into the unit's socket as many connections can happen during this action. If this occurs, the event buffer can be overwritten and any genuine events that were recorded will now be erased.
While storing the unit between jobs, apply mains to the unit (only one channel is needed on the 836i). This will remove any current draw from the battery while the unit is sitting on the shelf doing nothing. Before the unit is installed on site, a quick download will confirm the unit is still operational as it has been recording while in storage.
All data should be downloaded before changing the battery. If the unit appears to not respond, the battery may well be flat. Try powering the unit (see the caution above) and attempt a download. If this fails, then the unit may well require a "cold start".
Note: Power must be disconnected when changing the battery on an LC-812. The battery negative is directly connected to the mains input Neutral. If accidentally swapped, this makes the battery live!
On an LC-836i it is suggested that the battery be changed with power applied. The inputs on the 836i are isolated from the circuitry through transformers. By applying power, the unit is not upset by having power removed (it is known for some versions of the LC-836i to 'lock' when the battery is changed making a "cold-start" necessary).
Obviously a note of caution has to be issued being that should there be any failure of any insulation within the LC-826i, then the battery could very well be live.
It has been reported by a number of users that the Duracell M3 appears to last longer than most.
Note: This web page does not form part of any official documentation.Any information contained herein is used at own risk.
© M.T.P. - 16.01.03