Garmin GPSMap 296 Loses Date and Time

[he1iaviator]

I have been having problems with my Garmin 296 (Firmware version 5.40) loosing the date and time when switched off for a week or so. Both main and standby batteries are keeping their charge well. The local Garmin agent was unable to find a fault and it has now been suggested that I return the unit to Garmin in the US. However I have just found that a nearby operator with a number of 296s (Firmware 5.20) is having the same problem with two of their units.

Is anyone else having this problem?

[Bushfiva]

I don't use this unit, but I know a lot of people believe the clock backup battery on the circuit board (which is used in several models) fails prematurely. If you're handy with a soldering iron, there's more info out on Google. If your battery is the Varta 621, replacements are going to be around $3 to $10.

[B Sousa]

I think the 296 is now in the Smithsonian Museum.......Time for an upgrade.
www.garmin.com (http://www.garmin.com)
Then when you find what you want. Look at EBAY or something like www.pricegrabber.com (http://www.pricegrabber.com)

[he1iaviator]

You may have unlimited funds Mr BS but I don't. The unit is only about three years old and has the latest firmware and Jeppesen database.

The Garmin service agent tested the clock back-up battery and said it was fine and did not need replacing. If this is a known problem I would have thought they might have mentioned it during the many emails we have exchanged.

[Bushfiva]

Well, even though it's not the problem, I wonder what they'd charge you to swap the battery out? The battery has a life of "more than 100" to "more than 1000" cycles, depending on how deeply it discharges. Since you say the problem is when it's off for a week or so, you have tried it with shorter periods and it's been OK. I guess you and/or your agent has done a factory reset?

[NotHomeMuch]

Have had the same problem with 2 of the 4 296's we have. By re setting the time and date it worked OK and also by leaving it on for a while - longest time was 3 hours! - we managed to get them sorted.

[Bushfiva]

That's interesting. That would possibly suggest the clock battery is only charging when the unit is powered up.

[500e]

Another great unit having consumer testing :{
"That's interesting. That would possibly suggest the clock battery is only charging when the unit is powered up."
The battery should last for longer than a week, (think of your watch battery driving live LCD \ hands 24\7) would suggest changing even if you are told it is OK, we deal with 100s of rechargeable,s of all sizes and the tester lies on occasions.:(
If its cheapish change it.
Is it a rechargeable or just a throw away if it is a non rechargeable replace it?

[Pandalet]

Do the Garmins use a rechargable system backup or a primary (usually lithium thionyl) cell (like the Skymaps)? If it's a primary cell, they're not rechargable, and need to be replaced when they (eventually) run out of charge. This is generally a pretty trivial operation, involving desoldering the old one and soldering a replacement in.

To be honest, with batteries being as cheap as they are, I'd be tempted to swap it out on a faulty unit regardless, just to be sure.

[spinwing]

Mmmm ...

I use a Garmin 495 and generally I'm very happy with the unit ....However .....

Just recently I've been having issues with "incomplete" battery charging.

I normally run 2 rechargable lithium batteries and swap them about at every recharge (usually daily). the batteries have different part Nos (which might reflect a product improvement?) .... when new both batteries charged fully ...now seem to only want to go to 1/2 charge before the software ceases the recharge leaving the battery showing 1/2 to 2/3 charged .... anybody else have similar issues?

:confused:

PS a friend uses the 276 and has similar problems!

[Pandalet]

Rechargable batteries have different ways of signalling to the charging circuitry that they're full, depending on the technology involved. This ranges from sinking a certain current to reaching a certain temperature. Ignoring these signs when charging a battery can result in the battery going boom (search some of the video sharing sites for what this looks like). Because of this, electronics manufacturers tend to err on the side of caution when they set up their charge circuits.

As batteries age, they lose the capacity to take a charge. This manifests as the "I'm full" signal coming earlier, which in turn results in less charge being stored in the battery. Thus the charging system says the battery is full (or rather, it can't be charged any more), while the level measurement (which shows charge remaining) says it's only half full.

How long have you had your rechargables, are they lithium ion or lithium polymer (not that this makes much difference), and how many charge/discharge cycles have they seen? Standard Li-Ions will be ok for around 1000 cycles (depending on use and charge speed), although they really don't like being left sitting for long periods with no charge. Li-Polys are a bit more forgiving, and the newer Li-FeO cells should be good for around 4000-5000 cycles (but I doubt there are any GPS units using these as yet).

In short, if your rechargable batteries are a bit old, and aren't holding charge like they used to, they probably need replacing.

[MiKeRoToR]

Hi Hel1aviation, i have the same problem, i dont know why happens :ugh: but i can help you to solution... to solve this problem.
You need to do a reboot of sistem, try at start to hold and push enter and on buttons or maybe quit (i dont remember)...
after this put the gps to caught signal (its probably that takes a bit longer)...

A have this problems to times (but i think that this is only a light solution)..
Good Look!!! and safety flights

[spinwing]

Pandelet ....

Garmin 495 is 6 months old and the batteries ... one is 9 months old the other came with the unit ....

I would have hoped to get 2-3 yrs out of them ???

Cheers :{

[Pandalet]

Garmin 495 is 6 months old and the batteries ... one is 9 months old the other came with the unit ....

Ah, that would point to some other issue than old batteries. I would have thought you'd get at least a year out of fresh batteries, even with a fairly abusive charge/discharge scheme. I can't suggest anything else - perhaps try the reset thing as posted by MikeRotor and others?

[Bushfiva]

Thread drift has caused massively different types of batteries to work their way into this thread. The original battery is named in post 2. Check its specs, it's the size of a zit. Deduce what any error in charging rate will do to it: it can do 1000 charges at 10% DOD, but only 100 deep charges. The difference between what it thinks is a deep discharge and a normal discharge is very small. Its capacity is 3mAh, rated at 0.01 mA (that's 10 microA) to 2V, it weighs a quarter of a gram. It's a graphite LiMNO cell. At the rated discharge, it's good for 12 days without external power.

Under perfect conditions, it may last 2 to 5 years. He1aviator's particular unit may or may not be suffering from a dead cell, but if I ever opened a piece of equipment and saw that cell, I'd swap it out on principle.

[B Sousa]

You may have unlimited funds Mr BS but I don't. The unit is only about three years old and has the latest firmware and Jeppesen database.


Sorry about that, some in life just seem to draw Lemons. Actually I was mistaken, and thought it was the 276. They are still out there and for sale cheap. An upgrade or so with a data base for whatever part of the world and they do OK.

I have had very good luck in dealing with Garmin and maybe you might consider sending it to the factory. Considering the area where you reside there may be some expense but as I have seen in the past, many of the Shade tree fixes dont work forever.

Good Luck

[spinwing]

Mmmmm ...

Ok re my post #10 I think I've found a fix .... I completely ran the both batteries down to the point of the GPS unit shutting itself down ......

I then activated the charge cycle and BOTH batteries charged FULLY.

It would appear the clever microprocessor could see the "Min charge" state and went to "Max charge" mode ..... "voila".... two fully charged batteries and a big grin on my face!

Cheers :ok:

[gafa1]

We had same problem in our 296's,
There is an internal battery that goes flat in them.
Here is a link on how to replace them yourself, but i would recommend to get someone that knows what they are doing to do it.

GPS Information.net Forum > • View topic - Garmin 276C has an internal battery that will start failing (http://www.gpsinformation.org/forum/viewtopic.php?t=4701)

just have to get someone to fuse the connectors onto the battery for you, and you will need static lines for when you solder the wires back on!:ok:

[zigsta]

Hi,
I'm considering purchasing a Garmin 496. Do any users have experience of flying with this in the heli routes etc? Is the additional cost justified when compared with the 296?

Is anyone upgrading to the 695 and considering selling their 496 unit?

[he1iaviator]

I was recently on a week long sailing trip :} with the 296 plugged in to the boat battery and switched on all the time. (One needs to know if the anchor is dragging while drinking chilled wine and eating lobster fresh from the sea!) For the last two weeks the unit has been switched off most of the time but it has managed to keep the correct time. This must mean that the clock battery is holding its charge. As it did not hold its charge, despite days of charging, when connected to the power supply but switched off I think I will try charging when switched on from now on and see if that does the trick.

Or maybe it just prefers sailing to flying in those noisy shaking machines :E