GPS mouse battery life

TonyP · Posted: Mon Jan 03, 2005 3:09 pm Post subject: GPS mouse battery life

Most GPS mice seem to have an internal backup battery to keep the volatile memory alive. When the battery runs down the unit has to do a factory reset next time it is turned on which can take a few minutes.

The battery life is not very long, for example the Royaltek Sapphire quotes the battery life at 4 days. That means that if you dont use the unit for 4 days you will have to wait for a factory reset fix next time.

Also as the battery ages, its capacity goes down. I'v had my Haicom 3 years and it wont keep the charge overnight .

It would be good to know the battery capacity of the units. Some units like the Garmin 18 use non volatile memory and dont require a backup battery.

lbendlin · Posted: Mon Jan 03, 2005 3:33 pm Post subject:

I think it would be much more useful to know the REMAINING battery capacity of a receiver. Unfortunately that's deep down in the firmware, and may not even get monitored.
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TonyP · Posted: Mon Jan 03, 2005 4:30 pm Post subject:

No, I am not talking about the battery in bluetooth units, but the backup battery for the memory in wired units.

I would like to know how long the unit or the car can be left unused before the battery runs out and the memory lost.

lbendlin · Posted: Mon Jan 03, 2005 4:34 pm Post subject:

We are talking about the same thing - the backup battery in serial receivers. I think it would be much more important to uxderstand how "old" the battery is. It may be able to hold 4 days when it's new. but after a year or two that may be down to half a day.
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TonyP · Posted: Mon Jan 03, 2005 4:59 pm Post subject:

Well, that might be useful to know too, but by then you have bought the thing and cant do much about it.

If I knew that the backup on a new unit lasted say 2 weeks then I would buy that rather than a unit with a 4 day capacity.

Even if the capacity of the 2 week unit dropped to a couple of days over the years, it would still be useable, but a 4 day unit that drops to a few hours is pretty well useless.

Even better would be a unit with non-volatile memory.

My Garmin eTrex just gave me a fix in less than a minute even after sitting in the drawer since August.

lbendlin · Posted: Mon Jan 03, 2005 5:16 pm Post subject:

Yes, NVRAM would definitely be better. But it's also more expensive. Maybe that's why they go for batteries.
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MikeB · Posted: Mon Jan 03, 2005 5:30 pm Post subject:

I believe that a lot of devices (experience from the days of Emtac and other BTGPS devices having to drain battery to get factory reset) don't actually use batteries, but use capacitors which store the juice when connected an then trickle it out over a few days.

When my BT GPS was drained it used to take about 5 or 6 days to discharge the capacitor. I am not sure if a similar design is used in the mouse GPS receivers, if so then the capacitor would probably have a different type of behaviour curve than a rechargeable battery over time.
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TonyP · Posted: Mon Jan 03, 2005 6:15 pm Post subject:

The Garmin 18 uses NVRAM. It doesnt seem to be available in Europe, but only costs $80 in the US. I am tempted to get one, but I am not sure how it behaves in town.

I am sure using NVRAM only costs a few dollars more, but I think it is worth it if the unit is likely to last more than a year or so.

lbendlin · Posted: Mon Jan 03, 2005 6:44 pm Post subject:

It may not be in the interest of the manufacturers to produce something that doesn't need to be replaced after a year... Evil or Very Mad

The Apple iPOD is an excellent example - poor, non-replaceable battery.
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TonyP · Posted: Mon Jan 03, 2005 7:09 pm Post subject:

Sure, I realise that, but I would like to see it in the comparison database.

To me a reliable unit is more important than a second or two on a hot fix.

People who are using a unit all the time and never give it a chance to run down may have different priorities.

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