Garmin 696 battery life

[DonMuncy]

How many hours of use is everyone getting out of their 696s. Mine has decided it will only last an hour and a half with low activity (just turning it on and letting it sit).

[Bob_Belville]

I don't think mine, 4 years old, is much different from yours or ever was. It is "hard wired" through the avionics master so the only time it is running on the internal battery would be an emergency or when I upload from Garmin SD cards.

[DonMuncy]

Bob,

I have mine hard wired as well. If we were to have a total electrical failure in the soup, it seems we should use the 696 and/or the IPad to get on the ground well within the hour or so of battery life. That shouldn't be too difficult; it isn't like we should have a total electrical failure without knowing if had happened.

I don't know exactly what my 696 battery did earlier, but it seems to have lasted better earlier.

[Bob_Belville]

Don, yeah, the 696 could be important w/o power in the soup. I do not carry computers for flying. My Aspen has some battery reserve, maybe 30 minutes? I have the 696 and a vacuum BU AI.

 

I did experience a problem a couple of years ago in IMC when a battery going bad confused the VR and resulting in the alternator kicking out. I had no problem aviating and navigating but communicating was failing as I shot an approach.

[donkaye]

How many hours of use is everyone getting out of their 696s. Mine has decided it will only last an hour and a half with low activity (just turning it on and letting it sit).

 

 

I think it is time for a new battery.  I think I replaced mine once when I had the 696.  If the XM is connected, then I remember the battery depletes in about 2.5 hours.  With it disconnected you should be getting 5-6 hours, if I remember correctly.  When I would fly commercially I would dim the display to increase the battery life.

 

It also might be time to upgrade to the 796 if you have or intend to put in the Flight Stream 210.  Within the next month it should be able, through bluetooth, to get ADS-B traffic and weather from the GDL 88, and attitude from the Flight Stream.  If you have a GDL 69 or 68A and an XM subscription for the 796 and don't flight instruct like I do where you need the XM separately from your airplane, then you could cancel your 796 XM subscription and get it through bluetooth from the GDL 69 or 69A.

[Bob_Belville]

I see the Garmin spec is 2.5-8 hours, nominal. Replacement battery seems to be $180-$200.

 

http://www8.garmin.com/aviation/brochures/07675GPSMAP/07675GPSMAP.pdf

[DonMuncy]

Thanks guys.

[MyNameIsNobody]

I don't think mine, 4 years old, is much different from yours or ever was. It is "hard wired" through the avionics master so the only time it is running on the internal battery would be an emergency or when I upload from Garmin SD cards.

+1

[StevenL757]

Don, I'm not a battery expert, but what I do know (and have experienced) is that this could be related to the way your aircraft charges the battery.

Having your 696 hard-wired charges your NiMH constantly whilst powered. Although a higher charge is a good thing, charging it (and leaving it at a fully-charged state) can have a negative effect, in that it will shorten the overall battery life. Rather than lasting ~400 charge cycles, constantly charging it to full and leaving it that way can reduce its life to ~300 charge cycles or less, as well as reduce the usable life of each successive charge. Letting it discharge fully and then recharge (similar to a NiCad) tends to allow it to last longer the older it gets.

[DonMuncy]

Steven,

I had previously heard that batteries had a longer life it they were often discharged and recharged. For some period of time, I have routinely (once every month or two) turned on the 696 with no external power and let it deplete down to where it gave a low battery indication . (Yes, I know, I should have mentioned this earlier.) But I did not leave it in a depleted state. I would charge it back up fairly quickly. 

When I would go out to fly, I would hook it into the ship's power and leave it plugged in for the duration of the flight.

So, the battery was virtually always in a fully (or close to it) state. 

What do you and everyone else think about this.

[Bob_Belville]

I know very little about a lot of useless stuff. But I'm a good friend of Ms. Google. http://www.tested.com/tech/1245-how-to-get-the-most-out-of-nimh-rechargeable-batteries/ So how should you actually handle your NiMH batteries?

Past all the confusion, there is some very solid, consistent advice about getting the most out of your batteries.

1. Be prepared to replace them, eventually. NiMH batteries don’t last forever, and though time and use they will stop working. Thank them for saving you money, recycle them, and move on.

2. Buy a good charger. You don’t have to spend a fortune on the best charger available, but make sure you get a “smart” charger, one that electronically monitors the recharge process and prevents overcharging. Not only is it better for the batteries, it will use less power than cheap chargers, which often rely on a simple timer mechanism.

3. Remove the batteries when the recharge is complete. Unnecessary time on the charger means more “trickle” power is used to keep them charged—so more wear and tear and more wasted power.

4. Don’t regularly discharge your batteries completely in an attempt to make them last longer. Despite all the advice to the contrary, complete discharge can actually shorten their lifespan.

5. Store your NiMH batteries at room temperature in a dry location. Excessive heat can definitely damage your batteries and cause them to lose charge faster.

6. Consider using low self-discharge battery model. Eneloop is the best known brand of these batteries, which unlike most NiMH cells don’t lose power as quickly when sitting on a shelf. If your rechargeables are ready to go, you’re less likely to fall back on the throwaways. 

[Marauder]

NiMH and NiCd batteries suffer from a memory problem. If you keep them constantly charged, they will begin having a shorter power cycle time. Lithium batteries on the other hand have no memory issues, but do a have a finite number of charge cycles.

If the lithium maximum number of full charges is 1000 cycles and you let it go down to 80% and charge it to 100%, this counts as 1/5th of a charge cycle. Do this 5 times and you have one complete charge cycle and have 999 more to go.

Sent from my iPad using Tapatalk

[FlyingDude]

Hi guys,

Does the 696 battery management unit take care of “avoiding constant trickle charge” on the battery? Shouldn’t be hard to implement that by sw, in theory.

Thanks