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Cellular forums Home > Archive > Garmin GPS > January 2006 > Caution: Watch Out for Batteries Too Long for Garmin Battery Compartment
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Caution: Watch Out for Batteries Too Long for Garmin Battery Compartment
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| Dan Anderson 2005-11-01, 5:48 pm |
| I've recently discovered that Powerex 2300 mAh NiMH batteries can
break the flat battery contact spring in a Garmin GPSmap 76S
receiver. The Powerex 2300 mAh batteries have a positive terminal
button that is longer than other batteries and squeezes the flat
battery contact spring too much eventually causing it to fail
where the spring folds over (at the bend). It may have taken a
few insertions before the spring broke in one case. In the next
case, it broke the first time.
This does NOT happen to all Garmin 76 series receivers. I have
been using these batteries in a Garmin GPS 76 and a GPSmap 76
since January 2005 without breaking any spring, although the fit
is extremely tight.
The positive terminal button on all other batteries that I have is
shorter than the button on the Powerex 2300 mAh. This includes
Powerex 2200 mAh batteries and NEXcell 2300 mAh batteries. So most
batteries probably don't have this risk. So far I don't have any
batteries with a capacity greater than 2300 mAh so I don't know if
any other larger capacity batteries have this risk.
--
Dan
(email change 2001 to 2004)
(www.gpsmap.net)
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| Hans-Georg Michna 2005-11-02, 5:48 pm |
| On Tue, 01 Nov 2005 23:53:21 GMT, "Chull"
<chull001@rochester.rr.Not Needed.com> wrote:
>well- I did wonder why the upper batter slot on my 76CS has no spring while
>the bottom one does...
So do I.
On the other hand, it seems to be quite advantageous to have
slightly bigger AA cells that fit tightly, because this
alleviates the shake interruption problems some Garmin receivers
have.
Of course, if the cells are so big that the case breaks, that's
no good.
Hans-Georg
--
No mail, please.
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| Hmm, I've been using Energizer 2500s since buying my 76CS a little over
a year ago. One of the flat contact springs has definitely flattened.
Did your's actually break? Since I've now gone beyond the one year
warranty period and if it did break on mine, I wonder if Garmin would
repair it for free.
Bob
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| Steve Quade 2005-11-06, 11:48 pm |
| I found a way to solve the problem in my Garmin 76CS with the top battery
mometarily losing contact with the metal contacts, which causes the GPS to
power off. I bought a length of adhesive backed, black foam weatherstripping
at the local Home Depot store. The foam I purchased is 10 ft long by 1/4"
thick by 3/4" wide. I cut a 1-1/2" long piece of this foam and then I cut
the width down to 1/2" and then attached the foam to the battery cover, so
that the foam pushes the top battery firmly into the battery compartment.
This pushes the battery against the metal contacts and since I added the
foam in February I have not had a single vibration power off incident.
Please note that the 1/4" thick foam will be very tight against the battery
at first but with time will crush down to make a very nice fit.
I don't know that this will solve the issue with the battery being too long
and breaking off the tab, but since many people mention the vibrate off
problem I thought I would share this fix with the group.
I use the GPSMAP 76CS for cycling so the vibration off problem was a real
headache until I did this fix.
"Dan Anderson" < danderson2001@hotmai
l.com> wrote in message
news:SNCdnSXa9rEhDfr
eRVn-uA@pghconnect.com...
> I've recently discovered that Powerex 2300 mAh NiMH batteries can break
> the flat battery contact spring in a Garmin GPSmap 76S receiver. The
> Powerex 2300 mAh batteries have a positive terminal button that is longer
> than other batteries and squeezes the flat battery contact spring too much
> eventually causing it to fail where the spring folds over (at the bend).
> It may have taken a few insertions before the spring broke in one case.
> In the next case, it broke the first time.
>
> This does NOT happen to all Garmin 76 series receivers. I have been using
> these batteries in a Garmin GPS 76 and a GPSmap 76 since January 2005
> without breaking any spring, although the fit is extremely tight.
>
> The positive terminal button on all other batteries that I have is shorter
> than the button on the Powerex 2300 mAh. This includes Powerex 2200 mAh
> batteries and NEXcell 2300 mAh batteries. So most batteries probably don't
> have this risk. So far I don't have any batteries with a capacity greater
> than 2300 mAh so I don't know if any other larger capacity batteries have
> this risk.
>
> --
> Dan
> (email change 2001 to 2004)
> (www.gpsmap.net)
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| MikeSoja 2006-01-10, 11:48 pm |
| On Tue, 01 Nov 2005 08:58:07 -0700, Dan Anderson
< danderson2001@hotmai
l.com> posted:
>I've recently discovered that Powerex 2300 mAh NiMH batteries can
>break the flat battery contact spring in a Garmin GPSmap 76S
>receiver. The Powerex 2300 mAh batteries have a positive terminal
>button that is longer than other batteries and squeezes the flat
>battery contact spring too much eventually causing it to fail
>where the spring folds over (at the bend). It may have taken a
>few insertions before the spring broke in one case. In the next
>case, it broke the first time.
>This does NOT happen to all Garmin 76 series receivers. I have
>been using these batteries in a Garmin GPS 76 and a GPSmap 76
>since January 2005 without breaking any spring, although the fit
>is extremely tight.
>The positive terminal button on all other batteries that I have is
>shorter than the button on the Powerex 2300 mAh. This includes
>Powerex 2200 mAh batteries and NEXcell 2300 mAh batteries. So most
>batteries probably don't have this risk. So far I don't have any
>batteries with a capacity greater than 2300 mAh so I don't know if
>any other larger capacity batteries have this risk.
'Tis an old thread, admittedly, but I've got a new GPSMap 76CS and
almost two dozen moderately used Powerex 2300 mah batteries on
hand, and the batteries really *are* too tight a fit for the new
unit. Fortunately, I'd read this thread last year, and approached
the problem cautiously, not wanting to break anything new and
expensive. Also, fortunately, I've some lesser mah batteries to
use, too.
I bought the Powerexes from Thomas-Distributing so I went back to
their site to poke around. They spec the Powerexes at 49.85 mm
long, but my little millimeter ruler puts them more at like 50.5 mm.
I don't think the T-D specs include the button on the end, but I
didn't make that measurement and didn't know that before I undertook
more sleuthing elsewhere.
I logged into the Thomas-Distributing help system and asked what
they recommended for a shorter battery. The illiterate there wrote
that he "like[d]" the Sanyo 2500 mah. I went to the Sanyo website
and found the specs for their NiMH batteries and they're pegged at
50.4 mm long! Now, that was when I still thought the Powerexes were
only 49.85 mm, so I wrote back to the Thomas guy and said I didn't
like his recommendation very much. He basically blew me off, and I
gave him a low "Review", and I haven't heard anything more from that
quarter.
I then found the Energizer website, bunnies and all, found their
specs, and they claim all their AA batteries are 50.5 mm long. Does
anyone have trouble jamming Energizers into the 76CS?
I got out my stainless steel Lufkin millimeter rule and started
measuring:
Maxell 1400 mah == 50.0 mm.
Monster Powercell 1800 mah == 50.0 mm.
GP2000 1900 mah == 50.0 mm.
Powerex 2300 mah == 50.5 mm.
The GP site "says" the NiMH batteries are 50.5 mm ...
http://www.gpbatteries.com.hk/html/techinfo/nimh.asp
Energizer (50.5 mm)...
http://data.energizer.com/DataSheets.aspx
Sanyo (50.4 mm) (you gotta fill in the form)...
http://www.sanyo.com/batteries/specs.cfm
Maha Powerex at Thomas (49.85 mm)...
http://thomasdistributing.com/ maha...e_batteries.php
Maha Powerex at Maha (50.0 mm)...
http://shop.mahaenergy.com/store/vi...0&cur=specs#mid
So...
Now I'm left not knowing who to believe or which specs are right.
I'm waiting for the Monster Powercell people to write me back, but
they've had all day, so I'm not holding my breath.
Anyone out there got a 2300 or better AA and a ruler?
Mike Soja
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| Bob Greschke 2006-01-10, 11:48 pm |
| > Now I'm left not knowing who to believe or which specs are right.
> I'm waiting for the Monster Powercell people to write me back, but
> they've had all day, so I'm not holding my breath.
>
> Anyone out there got a 2300 or better AA and a ruler?
>
> Mike Soja
Powerex 2000 ~49.6mm
Powerex 2300 just below 50.0mm
Powerex 2500 a pretty solid 50.0mm
Duracell Ultra 51.0mm
Bob
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| Mike,
I've been using Energizer 2500s in my 76CS for about a year and a half.
They are tight but haven't caused any damage. I bought an 8 pack and
they measure between 1.968-1.971" long (48.987-50.063 mm).
To solve the problem with getting them out, I first put a piece of
ribbon about an inch wide into the bottom of the battery compartment
then push the batteries in. With the ribbon extending about a half inch
on each side I'm able to gently lift the batteries out. Of course I had
to cut a hole into the middle of the ribbon to clear the latching boss.
Bob
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| MikeSoja 2006-01-10, 11:48 pm |
| On Tue, 10 Jan 2006 20:05:42 -0700, "Bob Greschke"
<bob@greschke.com> posted:
[color=darkred]
[color=darkred]
>Powerex 2000 ~49.6mm
>Powerex 2300 just below 50.0mm
>Powerex 2500 a pretty solid 50.0mm
>Duracell Ultra 51.0mm
Holey Moley. I think the Duracell is out.
Now I know why most battery compartments have such big springs in
them, but I'm still surprised there is that much variance in what I
thought would be rigorously standardized, mass produced item.
I wonder how much extra power they manage to add just by making the
battery bigger.
Mike Soja
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| MikeSoja 2006-01-11, 2:48 am |
| On 10 Jan 2006 19:06:45 -0800, "Bob" < clintonstreet3@veriz
on.net>
posted:
>Mike,
>I've been using Energizer 2500s in my 76CS for about a year and a half.
>They are tight but haven't caused any damage. I bought an 8 pack and
>they measure between 1.968-1.971" long (48.987-50.063 mm).
That variance just amazes me. And what are you using to measure?
Digital calipers?
>To solve the problem with getting them out, I first put a piece of
>ribbon about an inch wide into the bottom of the battery compartment
>then push the batteries in. With the ribbon extending about a half inch
>on each side I'm able to gently lift the batteries out. Of course I had
>to cut a hole into the middle of the ribbon to clear the latching boss.
That's tight. Too freakin' tight. I haven't decided which brand to
try, yet, but I'll drop a post here when new batteries arrive.
Mike Soja
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| David Lee 2006-01-11, 5:48 pm |
| Jack Erbes wrote...
> Battery length is only part of the problem. A bigger issue is the flawed
> design on the Garmin battery cases. The flat springs used are too closely
> spaced and/or don't have an inadequate working and holding range to them.
> They make poor contact and are doomed to failure because they get
> overstressed during battery insertion.
>
> I'd be very surprised to find that there is not some internationally
> recognized range that the battery sizes do not have to fall into. The
> designers were either unaware of the range of battery sizes or that they
> did not work out an intelligent solution to accommodating it.
>
> The Magellans use coiled springs on both ends of the battery. The (+) end
> is a nearly flat wound coil with a short travel range, the (-) end has
> about 5/16ths of an inch (8mm) of travel.
>
> The long springs are at opposite ends of the battery case and are easily
> compressed as the batteries snap down and into the case. I like the fact
> that I can use my finger to find the spring and the flat end of the
> battery to get the batteries in right on the first try when I am replacing
> them in the darkness.
>
> Maybe Garmin is saving a few pennies on each unit by using the flat
> springs?
No - the Garmin design is a good idea badly engineered. The problem with
coiled springs is that they can be damaged if you try to extract a cell by
prising out the end in contact with the coil. Garmin get around this by
using only flat springs at the bottom end of the unit so you can safely lift
out either cell from this end and insert them the same way. Additionally,
because the lower contact assembly comprises a single piece of spring metal
there are no electrical joints at this end to fail - other than contact to
the batteries themselves - as ther would be if a coil spring had to be
joined to a flat one where the cells are connected in series. Problem seems
to be that the size of the battery enclosure appears to have been designed
for the coil spring solution and there is a lot less tolerance on the other
side of the battery compartment.
There also appears to be a significant difference between the casing of a
yellow etrex and a Vista, in the battery compartment. In each case the
spring strip at the positive end of the compartment is mounted in a slot in
the plastic casing. In the my basic etrex the button of each cell can slide
into this slot giving more play and a greater amount of spring travel. This
reduces the insertion force and ensures that all the spring pressure is
being borne by the electrical terminals. In the Vista, on the other hand,
this does not occur and it appears that most of the contact force on the
cell buttons may be bearing on the plastic rather than the spring terminals.
Additionally the cells require a much greater insertion force, which is
likely to cause more flattening of the springs, particularlythe flat one at
the negative end of the right hand cell.
However, I can't help wondering whether this really is always the source of
the bad connection problem. Maybe there may also be corrosion problems
leading to intermittently poor contact at the wire-wrap terminals at the top
end of the battery compartment or the crimp between the top +ve terminal
spring and the connecting wire. Just a thought.
David
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| 30 milliamps per millimeter.
Assuming it's a standard 1500 mAh battery.
"MikeSoja" <msoja9@newsguy.com> wrote in message
news:n1u8s19nagv5bpb
utulapbfrmotvdi52po@
4ax.com...
> I wonder how much extra power they manage to add just by making the
> battery bigger.
>
> Mike Soja
>
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