Weirdly enough I replaced mine with a brand new battery and the error is still there.
Has anyone seen sb1963? It must be a dealer-only document, because it doesn’t google to anything. I wonder if it has any useful info in it, or just an authorisation for a Garmin dealer to do the work as per the MM?
The other thing I wonder is whether the battery backed up CMOS RAM stores anything other than user-entered data. If it does, then changing it without using that procedure to preserve the data will lose things like any OBS offset, so any connected device with an “RMI” presentation will need adjusting.
Weirdly enough I replaced mine with a brand new battery and the error is still there.
Maybe there is a “factory settings” procedure one needs to run, which recalculates a checksum, which is needed because just changing the battery by removal and soldering in a new one has corrupted the data.
I posted the MM above. It escaped into the wild only a few years ago; this is a very rare thing for Garmin. It is pretty bare though and totally unlike the King MMs which actually contained useful info. Garmin don’t want field repairs done…
I have just asked a Garmin dealer friend in the US and he says he cannot find this SB. He says the MM has the whole battery changing procedure.
Yea I had read that bit of the manual before. No mention of having to do a reset. There’s a way to display the battery voltage in test mode so if I try it again I might try and power up the unit on the bench to verify its worked before re-installing.
I have the SB (see extract below) but can’t publish it as it’s Garmin proprietary data issued to dealers. It does allow a local dealer to do the work rather than paying the full Garmin flat-rate repair fee.
Interesting. Are the instructions in the SB different to those in the MM above?
Peter wrote:
The other thing I wonder is whether the battery backed up CMOS RAM stores anything other than user-entered data.
It must store the GPS almanac and previous position — otherwise every time you powered on the GPS it would be a cold start with a 12.5 minute delay until the first fix.
Straubing avionics will take around 400eur for that.
You can do this by yourself just by a little bit skill of soldering.
I don’t to this for my customers only because of guaranty. I can’t earn on this job super money and on other hand I’m risking to destroy very expensive unit so risk is not worth profit.
There is no reason to use a battery. It is just lazy design.
If you need nonvolatile storage of rapidly changing data (which would wear out an eeprom or flash) then a supercap will support a CMOS SRAM for some weeks and it doesn’t have the problems of primary cells (need to be replaced when discharged) or the problems of rechargeable cells (poor lifetime c. 5-10 years depending on quality, after which they tend to go short-circuit and render the whole product useless).
And anything which isn’t rewritten many thousands of times can go into eeprom/flash anyway. All product config and user entered data can. Even the satellite data can be written into flash when the product is powered off, and that removes the need for RAM based storage of just about everything. And this was possible in the late 1980s onwards.
The only thing which needs a power source is a real time clock, but a GPS box gets UTC from the GPS receiver 
Any GPS satellite signal gives you UTC instantly; you don’t need the almanac, a position fix, etc. I’ve just done a design with a little supercap (0.22 farad; cost about ten bob) which runs an ARM ST32F clock for over a week. In 1991 I did a design with a DS1302 clock chip (cost about ten bob too) which would run from a 2016 lithium cell for the shelf life of the cell i.e. about 20 years. And the DS1302 has about 30 bytes of SRAM.
So I wonder what these designers have been smoking all these years, using batteries the size of a tank and which need replacing too often.
The KLN94 is the same. A big fat primary lithium battery and it lasts maybe 5 years. Very easy to change fortunately, without losing data (using that procedure with a temporary resistor trick). But then King designers mostly went to Garmin
Can anyone recommend where I can get a 430 battery changed at a reasonable price in the UK?
Get your 430 out, open it according to the procedure doc further up and then
…if you are experienced and equipped for precision soldering: remove the old and solder in the new standard 3V battery
…if you are like me: find someone who does this small but important solder job for you (time reqired 5-10min, in my case on a box in the hangar)
Screw it back together, fix in the cockpit and power up.
Done my 530 like that. Works perfectly.
