extending battery life for nuvi

 

Has anyone tried using any of those solar powered chargers for a nuvi? Like solio.com, power monkey or any others? They list that solio will charge the Garmin forerunner specifically, cell phones, ipods and pda's but do not list any other specifics for GPS. I sent them an email but just curious if anyone has any feedback. I figure for walking around in a city, it would be a great back-up source if they work.

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Why not be lazy...

...and just use one of those AA or 9V battery powered chargers to re-charge the Nuvi?

This thread has been beaten around this site before, and the concern is always about volts/amps/charging rate from non-Nuvi designed gadgets.

GC

--
Nuvi 350, GPS Map 76CX

Why not be lazy...

...and just use one of those AA or 9V battery powered chargers to re-charge the Nuvi?

This thread has been beaten around this site before, and the concern is always about volts/amps/charging rate from non-Nuvi designed gadgets.

GC

--
Nuvi 350, GPS Map 76CX

5 Watt

The power monkey says it will fit the nuvi with the blackberry adapter. The power with the power monkey says it has a 5 watt output. The nuvi cord says 5Watt 1000a so it does match. I was just curious how well it recharges it or if it runs off the secondary battery instead? Let's face it, the nuvi battery only lasts about 3-4 hours any extension is a great feat!

What???

PaulATL wrote:

The power monkey says it will fit the nuvi with the blackberry adapter. The power with the power monkey says it has a 5 watt output. The nuvi cord says 5Watt 1000a so it does match. I was just curious how well it recharges it or if it runs off the secondary battery instead? Let's face it, the nuvi battery only lasts about 3-4 hours any extension is a great feat!

If that thing puts out 1000a, must need some huge wire.laugh out loud

Might be 5v @ 1000ma??

RT

--
"Internet: As Yogi Berra would say, "Don't believe 90% of what you read, and verify the other half."

USB data

I am surprised to see someone also thinks like i do.

I face two problems with this.
1. solar panel dont generate enough current to supply directly pump in to garmin.
2. I am searching for garmin USB charger info. i use standard USB specs garmin goes in to lock mode.

--
Dont drink and drive. Be aware of low flying aircrafts. Drive as fast as you can and go to Jail.

.

PaulATL wrote:

The power monkey says it will fit the nuvi with the blackberry adapter. The power with the power monkey says it has a 5 watt output. The nuvi cord says 5Watt 1000a so it does match. I was just curious how well it recharges it or if it runs off the secondary battery instead? Let's face it, the nuvi battery only lasts about 3-4 hours any extension is a great feat!

Watts = voltage x amprage.

So I doubt it says 5 watts and then the amps. and as RT already stated, it is probably 1000ma

--
Charley - Nuvi 350 - Bel STI Driver - Cobra 29 w/ wilson 1000 - AIM: asianfire -

5V 1000ma

Yes, sorry, the Garmin charger says 5V 1000ma output and on the other side of it it says 5V 1.0A (5W).

For the Powermonkey, I was looking at that one since it has the capability to also charge my motorola phone, blackberry, and ipod.

I found on this website http://www.earthtechproducts.com/p2588.html that the adapter is XDA for the Garmin but can't find the specific adapter there, through powermonkey or any online searches. It's nice and small and can be charged via USB, Plug which they include EU adpaters or solar, that's what inspired me.

Solio info

The Solio solar panel output: 165ma @ 6v or about 1 watt. It's rechargeable li-ion battery is 3.6v - 1600 maAh which is similar to the battery in my 650 (3.7v - 1500mAh) The only charging option with the Solio is the mini-usb adapter or at least on the 650. I'm not sure I'd want to use the solar panel to actually power the Garmin but the unit might be fine to use as an extra capacity battery and later use the panel to recharge the battery when not attached to the Garmin.

--
Garmin nüvi 1390

Walkabout NUVI power

Have a look at my post http://www.poi-factory.com/node/10701 - The answer is reasonably simple once you take the cable problem out (plug type determines if it is charge and data or charge and navigate) though some other users with different models have suggested ways to beat that.

I have a NUVI 250 - battery inside just over 1000mAh - so if it lasts 4 hours that is a consumption of just over 250mA per hour. Means that your power input has to be that or better. Look for a replacement battery for your model to get your specs.

Voltage is important - not because you might let out light and magic smoke - actually the opposite - too far above USB spec of 5VDC (I believe + or - 0.5VDC) and the GARMIN appears to have high voltage protection built in - it just will not work.

I am still playing with ways to REDUCE voltage on my highly charged AA NiMH sets and you would not believe how hard it is to get USB plugs with wires the strength/size of the GARMIN car charger cable (or even USB plugs to solder wires onto!)

Get ready for the magic smoke ;-)

pchinote wrote:

I am still playing with ways to REDUCE voltage on my highly charged AA NiMH sets

I have thought of a simple solution - but promise not to laugh!

If you were to shunt a 1N5338 5.1V 5W Zener Diode, straight across the o/p of the battery pack (inside your cute little box) - that might do the trick.

Now - I know you might think that at this point a small fire may ensue - but I reckon, the internal resistance of the average NiMh cell should just about keep things in check. (I measured mine at about 0.3ohm).

So: 4x0.3 =1.2ohm. Max current that the zener can survive is 0.98A - so voltage drop across internal resistance would be 0.98 x 1.2=1.176V, in this case.

In other words, if the battery voltage is less than or equal to 5.1+1.2=6.3V (1.575V per cell), then the Zener should survive.

When the average cell voltage drops to 5.1 / 4 = 1.275V, the Zener will stop conducting.

Here's a link to the component I mean:
arrow http://www.rapidonline.com/productinfo.aspx?&tier1=Electroni...

My plan would be to be buy half-a-dozen and select one at the highest end of the tolerance range.(The ones with a "B" suffix have a tolerance of 5%)

Of course, cell internal resistances will vary, so some experimentation is required.

Ok, now you can laugh smile

--
------------------------ Phil Hornby, Stockport, England ----------------------               http://GeePeeEx.com - Garmin POI Creation made easy           »      

That's Cool

That's cool but just way too complicated. smile

The major power consumption

The major power consumption comes from the LCD display. By lowering the brightness to half of the full scale my internal battery on Nuvi 350 can last 5 hours straight, quite enough for me.

Need another GPS

Phil:
Honestly, I'm not laughing at you. I'm a simple minded person. Electronics is never my cup of tea. I would get another GPS. By the time the battery in my Nuvi 660 is dead, I would find a reason to buy a newer one with more bells and whistles. Better yet, charm my wife to get one. So far, she bought the last 3 that I owned. Life is good.

Zenner Diode Idea

Hornbyp wrote:
pchinote wrote:

I am still playing with ways to REDUCE voltage on my highly charged AA NiMH sets

I have thought of a simple solution - but promise not to laugh!

If you were to shunt a 1N5338 5.1V 5W Zener Diode, straight across the o/p of the battery pack (inside your cute little box) - that might do the trick.

.........

Ok, now you can laugh smile

Trust me - I am not laughing as the concept has been raised with me by a magic smoke geek. Just not so well explained so it is now number one on my list of things to try. So what if the magic smoke gets out of the diode? Not expensive and the GARMIN has high voltage protection.

Tolerances...

I wrote:

My plan would be to be buy half-a-dozen and select one at the highest end of the tolerance range.(The ones with a "B" suffix have a tolerance of 5%)

I just received a batch of 10 of these to play with. Every one of them is lower than the rated 5.1V (the highest value is only 4.78V).

On that basis, you might be as well trying 5.6V Zeners.

--
------------------------ Phil Hornby, Stockport, England ----------------------               http://GeePeeEx.com - Garmin POI Creation made easy           »      

Charging a Li-Ion battery

Li-Ion batteries are not as simple to charge as NiCad batteries. Remember the problems of notebook computers causing a fire. The problem is detecting when to shut off the charging. Most chargers are matched to the batteries they are made for. Typically they reduce the charge current after the voltage reaches about 4.0 volts per cell which is about 70% of full charge. Charging then continues until at a continuing reduction in current down to about 3% of the initial charge current and the voltage is about 4.2 volts per cell. These batteries do not tolerate continuous overcharge or trickle charge which can damage the battery.

And? ...

Mike107 wrote:

Li-Ion batteries are not as simple to charge as NiCad batteries. {snip part about how Li-Ion charge circuits work} These batteries do not tolerate continuous overcharge or trickle charge which can damage the battery.

And? ...

What does your post have to do with the above discussion of an external power source hooked up to the GPS?

PT

--
Garmin nüvi 200 (my first GPS), 780, & 3700 Series. And a Mac user.

Nuvi battery is Li-Ion

The Nuvi 250 battery is 1250mAh Li-Ion so I would look at the point about continuous trickle charge with a little interest. I do no think over charging is a problem with our external backup battery idea but the potential for trickle charge is there so back to basics....

In the car I suspect that the usual operation would be a trickle charge (keeping it topped up) if that is how it works - perhaps it bypasses the battery once the battery is charged and only hits it occasionally for a topup. Does anyone know?

Given the life of devices like this these days I suspect we will all have the new model with bells and whistles long before our batteries croak. And a new battery is under US$30!

It's relevant

Guttermouth wrote:

What does your post have to do with the above discussion of an external power source hooked up to the GPS?
PT

The external battery might act as a charger and try to "charge" the internal battery if the internal battery is low. Without some sort of current protection between the two, it's possible that it could overheat the internal battery or even both. Not that likely, but possible. We don't know if the current and voltage limiting circuits are in the charger or inside the Nuvi. You would hope that they are inside the Nuvi.

Ever jump start a dead battery and see the sparks when you connect the jumper cables? Lots of current flowing from the good battery to the dead one even though the disabled car is turned off.

Not relevant...

It isn't relative because the point you guys are missing is that the charging circuitry for the lithium ion battery is built into the nuvi itself. All we do is provide a power source (USB port, car adapter, external power pack, etc.) and the nuvi's internal charge circuitry does the rest.

Therefore using an external power pack is no different than plugging it into a computer USB port and there is absolutely no chance that you can accidentally continuously trickle charge the internal Li-Ion battery unless there is an actual failure or defect with the internal charging circuitry.

Of course if you want to actually USE the nuvi at the same time as the external power pack is plugged in, then you will need to configure the USB data lines as well to keep it from going into Mass storage mode. But if you just want to simply charge the Nuvi, you can just supply it with voltage from a battery pack and be done with it.

So to answer both concerns to the two posts above this one, yes the Nuvi has the internal circuitry to current limit any charging activity and will regulate both current and voltage to the battery itself. And yes, the internal charge circuitry will turn off all charging to the li-ion battery once the battery reaches full charge. There is no trickle (or float) charging allowed with Li-ion battery systems like you can with a car's lead acid battery.

Trickle charging a Li-Ion battery continuously is asking for an explosion and all Li-Ion charging circuits will have a cut off when fully charged and is why all Li-Ion battery devices build the charge circuit into the device itself such as cell phones, iPods, Garmins, etc. The wall adapters that come with these devices are nothing more than plain old transformers that supply a voltage and have no "smarts" at all.

Hope that helps,
PT

--
Garmin nüvi 200 (my first GPS), 780, & 3700 Series. And a Mac user.

Explosion imminent?

Guttermouth wrote:

Trickle charging a Li-Ion battery continuously is asking for an explosion and all Li-Ion charging circuits will have a cut off when fully charged

I've not figured out how to capture it - but the Battery Diagnostics screen on my Nüvi 310 definitely says
Batt State: Trickle as I write this exclaim

Whether that's what it really means, is another matter...

EDIT:

My StreetPilot C510 has just finished charging. It now says
Batt State. Suspend

--
------------------------ Phil Hornby, Stockport, England ----------------------               http://GeePeeEx.com - Garmin POI Creation made easy           »      

More charge stuff

Ya, as I said in my previous post, CONTINUOUS trickle charging (aka "Float charge") is not allowed, or good for, a Li-Ion battery like you can do with a lead acid battery. The battery will trickle charge for a period usually during two different states of the charge process.

The first is when it nears the end of the charge cycle and the voltage on the battery is nearing the 4.2V or so that indicates a full battery. As it approaches full charge the charging current goes down and will slow charge the final bit of the battery. Generally a Li-Ion battery will charge at full current until something like 80% full charge then begin to cut back the charge current. But once it reaches full charge, as your C510 indicated, all charging will stop even if you leave it plugged in.

The other time a Li-Ion will trickle charge is if the battery is VERY low. When a battery is below what would be considered a safe voltage level, usually you trickle charge the battery slowly until the voltage reaches a safe low voltage level. During this time you often won't be able to turn on the device at all so you won't see any indication of a charge happening. Once it reached the lowest "safe" voltage level, the charge will then switch to fast charging using the biggest current allowed by the charging circuitry and at this point you will usually be allowed to turn on the device (or it will come on automatically at this point if that is the way it works).\

Let us know if you nuvi 310 reaches a "suspended" state as well. It should.

PT

--
Garmin nüvi 200 (my first GPS), 780, & 3700 Series. And a Mac user.

eventually....

Guttermouth wrote:

Let us know if you nuvi 310 reaches a "suspended" state as well. It should.

The phrase it settled for (5 hours later) was "Done".

On the Nüvi, there is an additional bit of information, not on the StreetPilot; this is the number of "Charge Cycles". For some reason, this has not changed from "23" for several months!?!

--
------------------------ Phil Hornby, Stockport, England ----------------------               http://GeePeeEx.com - Garmin POI Creation made easy           »      

so getting back to the original feed

My dilema was that since I will be using the nuvi 350 as a city tour guide in battery mode (maps and poi's not music) I would like to add to the battery life. I know all the essentials for extending as in turn the screen light all the way down, off WAAS, and do not keep pressing buttons but I will probably need something for a full day of walking without an outlet to plug into and not 6hours. This is what led me to the Power Monkey and Solio solar panel.

It is believed that plugging these into the nuvi may only be a charge source and not be able to use off the solar/battery pack until charged? Not like the car cig adaptor and continue to be "ON" instead of "in charge mode", is this correct? Charging can take 4 hours. Has anyone tried this or should I be the first?

I understand

I am a otr bus driver over the So West. Some of our buses do not have a plug in that work so I am getting the PowerPort-312 12 volt, 12 amp hour rechargeable battery, with DC outlets, padded bag. I hope that I do not kill my c330. You can look at it at http://www.powerportstore.com/power.htm. please tell me if it is okay or not. Maybe you can tell me better.

--
Southern CA Temp 76 and Sunny. Running around with my Nuvi 465T. Getting lost around the country and loving it.

Just looked at this

Seems like overkill. I don't belive it will harm your unit, but the 73 seems like all you would need.

That said, if you have the room to place it on the bus, then by all means go for it. I would be willing to bet that it will last a lot longer than 12 hours if you are only connecting a c330 to it.

--
Glenn - Southern MD; SP C330 / Nuvi 750 / Nuvi 265WT

The 73

The 73 looks like it would work for me too but to carry around a 8 pound kleenex box is still too heavy and bulky.

I really like the idea of the solar power and it would be cool if I could attach that to my back pack and the GPS would "run off of it" until the sun went down but it is to charge the solar battery then use that to charge the unit. I guess you could always charge it up when you stop for lunch or are indoors on a tour! But then the powermonkey is smaller and takes less time to charge.

Ya the problem with the

Ya the problem with the "Solar Slave" is that it only puts out 200mA and that is probably only when in full sun (specs don't say for sure). So if you are running the GPS at the same time, it will likely be pulling more than 200mA so you would still be losing battery power over time.

However, this isn't to say that the Solar Slave wouldn't help extend battery life. For example, if the unit uses, let's say, a half amp (500mA) normally and you tend to get 5 hours of battery life. And let's say the solor slave on average gives you about 100mA of power. Then your 5 hours of battery should now be somewhere north of 6 hours of batteyr time. So that is something at least.

And as you mentioned if you stop for lunch at a nice outdoor cafe, you can always power off the GPS and let the Solar Slave charge up the battery for the next hour.

Of course the other problem is, you say you want to use it to be able to use it with other devices you have, so you will have to decide which devices are the most important to get charging over others.

But also the included battery pack would give you some reserve.

PT

--
Garmin nüvi 200 (my first GPS), 780, & 3700 Series. And a Mac user.

Battery Check

OK, so leaving my screen light set to only 2 bars, off waas and just leaving the nuvi in the map mode and checking from time to time it seems that after 3 hours, I just went into two bars left so I would assume 6 hours on battery.

I went to the battery test page to see what was left but not sure it really relates to the charge that's left? Any idea what time is left from this?

Currently after 3.2 hours now it reads:
Batt State Ok Cap
Vbattery: 3.76
BattCap: 40
Bat Chrg 1 mA: -195
Bat Chrg mAhr: 538
Chrg Cycles: 30
Vexternal: ___
Temp: 25t

2.75 more hours!

PaulATL wrote:

Currently after 3.2 hours now it reads:
Batt State Ok Cap
Vbattery: 3.76
BattCap: 40
Bat Chrg 1 mA: -195
Bat Chrg mAhr: 538
Chrg Cycles: 30
Vexternal: ___
Temp: 25t

Interesting.

It looks like it does run just under 200mA, the rating of the Solar Slave. The -195 I believe means it is using 195mA of current from the battery. A positive number woul mean it is charging, a negative it is discharging.

It also indicates that charge remaining is about 538mA-hours. Assuming that means until shutdown (rather than completely draining the battery) at 195mA of current draw you should have about 2.75 hours left of battery power.

Of course that is all speculation that I am interpretting those messages the same way Garmin intended them.

PT

--
Garmin nüvi 200 (my first GPS), 780, & 3700 Series. And a Mac user.

after 5.25 hours

Guttermouth wrote:
PaulATL wrote:

It looks like it does run just under 200mA, the rating of the Solar Slave. The -195 I believe means it is using 195mA of current from the battery. A positive number woul mean it is charging, a negative it is discharging.

It also indicates that charge remaining is about 538mA-hours. Assuming that means until shutdown (rather than completely draining the battery) at 195mA of current draw you should have about 2.75 hours left of battery power.

PT

OK, So then my starting mA should be at about 800? I think that does make sense then. I still have the unit on (I wanted to see how long till it says battery low) to get a more "true" battery time. As soon as the bars went down to 1 after 5.25 hours I checked the Battery screen again.

Batt after 5.25 hours:
vbattery 3.71
batt cap 21
batt chrg 1 mA -194
bat chrg mAhr 287
chrg cycles 30
temp 24t

Dual Outlet Car Adapters

I used to have a thingy that plugged into my lighter and give me two outlets.

If you did that, you could just use your car to charge the Garmin.

The Garmin works best when you are moving in a vehicle (smile).

Jen

Walking Mode

jennyzita wrote:

I used to have a thingy that plugged into my lighter and give me two outlets.

If you did that, you could just use your car to charge the Garmin.

The Garmin works best when you are moving in a vehicle (smile).

Jen

If you look back at the original post, you'll see Paul is interest in using it while walking.

--
Nuvi 660 -- and not upgrading it or maps until Garmin fixes long-standing bugs/problems, and get maps to where they are much more current, AND corrected on a more timely basis when advised of mistakes.

Walking NUVI

So now we are back to my AA battery pack idea - which works A-OK with no extra fiddles (except the need to use the GARMIN cable to bring the power in so it does not go to Mass Storage mode) AND/OR the idea that ANY battery pack (or power source like the solar) will work if it has enough mA to sustain the unit use AND is in the 5VDC + or - a little that is the USB spec.

(For anyone wondering I still have to find the time to try the zenner diode trick)

Power Chimp

pchinote wrote:

So now we are back to my AA battery pack idea - which works A-OK with no extra fiddles (except the need to use the GARMIN cable to bring the power in so it does not go to Mass Storage mode) AND/OR the idea that ANY battery pack (or power source like the solar) will work if it has enough mA to sustain the unit use AND is in the 5VDC + or - a little that is the USB spec.

(For anyone wondering I still have to find the time to try the zenner diode trick)

It looks like your idea is here. It is called the Powerchimp. It takes 2 x AA Ni-MH 1800mAh and can be powered in the same ways as the monkey. It is coming out sometime this year for ~ $56. http://www.powergorilla.com/

Battery Extender for Nuvi 750 and others

I found a web site that will probably solve all your NUVI Battery Extender WANTS!!!!!

http://www.gomadic.com/brand-garmin-accessories-garmin-nuvi-...

and for the 750 it is only $19.95 !!!!!!!

This link is for the NUVI 750 but once there you can backup to see the other Garmin GPSs

H Hannah
Nuvi 750 and IQUE 3600

--
"Those that stop and smell the roses, must realize that once in awhile you may get a whiff of fertilizer."..copyright:HDHannah1986 -Mercedes GPS - UCONNECT 430N Chrysler T&C - Nuvi 2598- Nuni2555 - Nuvi855 - Nuvi295W - Nuvi 750 - Ique 3600

Going Green

H Hannah wrote:

I found a web site that will probably solve all your NUVI Battery Extender WANTS!!!!!

http://www.gomadic.com/brand-garmin-accessories-garmin-nuvi-...

and for the 750 it is only $19.95 !!!!!!!

This link is for the NUVI 750 but once there you can backup to see the other Garmin GPSs

H Hannah
Nuvi 750 and IQUE 3600

That'll work too. I went with the monkey though since I want to try out the solar feature for it and go green if possible. If I can avoid a wall outlet completely it is worth the extra price of not having to carry around EU plug adaptors and power converters or buy more batteries.

Nice site

Thanks for sharing.
Gage

--
Gage with a nuvi 350 and 200

4 x AAA cells - not good :-(

pchinote wrote:

So now we are back to my AA battery pack idea - which works A-OK with no extra fiddles

I just tried a simple 4xAAA battery box with my Nüvi 310 - but the results were very poor.
The box itself had a 'Nokia-phone type socket', but was supplied with an adaptor to change that into a full-size USB. The box has an on/off switch.

So, by using a short USB->mini-USB lead, I was able to connect it to the Nüvi's (side) usb connector. Turning the box On sent the Nüvi into mass-storage mode - turning it Off and then back On as the Nüvi reboots lets the Nüvi enter navigational mode.
Because the Nüvi senses the external power, it disables the auto backlight-off function, which is one problem.

Problem #2 is that the o/p of the box soon dropped to 4.8V using NiMh cells. Although there was never a point where the Nüvi 310 thought the input was too high, it objected violently when the voltage became too low.

Having flattened the internal battery first, run-time on the external battery pack was only around 25 minutes (bluetooth connected, screen max. brightness). There was probably plenty of charge left in the 750mA.hr cells - but the voltage drop meant that it couldn't be used. As the voltage dropped, the Nüvi became unstable - rebooting and entering all manner of strange states sad

So, it seems that any practical, external power supply has to be able to maintain the voltage within the stated USB limits.

Potentially, the Gomadic product looks like it might do this:

"The output power of the AA extender really depends on the type of batteries that are installed. The output power of the charger is regulated at 5.0 vdc (like all gomadic chargers), however, the amperage available will depend on the type (and remaining life) of the batteries installed."

--
------------------------ Phil Hornby, Stockport, England ----------------------               http://GeePeeEx.com - Garmin POI Creation made easy           »      

To charge or not to charge?

I made it all the way through this thread and didn't find the answer I was looking for (maybe I missed it)...

I have a 660. Is it better to pull the plug overnight in the car so it doesn't keep power on? Or can I just leave it plugged in all the time? I used to leave it plugged in all the time until the battery died and had to be replaced (coincidence?).

Thanks.

The Power Monkey

So I got the power monkey. Here's the scoop. It works great for cell phones, ipod and such but it requires a different tip since the mini USB puts the nuvi into a the mass storage mode. You need the XDA tip for it. So I had to special order one which when it arrives I'll update further.

FYI

PaulATL wrote:

So I got the power monkey. Here's the scoop. It works great for cell phones, ipod and such but it requires a different tip since the mini USB puts the nuvi into a the mass storage mode. You need the XDA tip for it. So I had to special order one which when it arrives I'll update further.

FYI - When Nuvi goes into Mass Storage mode, it still recharges your battery.

--
nüvi 3590LMT "always backup your files"

Did not know

bandaid wrote:
PaulATL wrote:

So I got the power monkey. Here's the scoop. It works great for cell phones, ipod and such but it requires a different tip since the mini USB puts the nuvi into a the mass storage mode. You need the XDA tip for it. So I had to special order one which when it arrives I'll update further.

FYI - When Nuvi goes into Mass Storage mode, it still recharges your battery.

I did not know that. Thanks for letting me know. I am hoping that the XDA tip (when it arrives) will let me run the unit at the same time like the car plug does. That would be ideal. But I needed a special camera battery tip anyways that I needed to order. If nothing else, I have a spare in case I lose one. The only thing I see as a improvement right away is to maybe include or be able to order a 3-4 foot cord So I can put the battery in a back pack while holind the nuvi.

Ideas are appreciated

Hornbyp wrote:
pchinote wrote:

So now we are back to my AA battery pack idea - which works A-OK with no extra fiddles

I just tried a simple 4xAAA battery box with my Nüvi 310 - but the results were very poor.Having flattened the internal battery first, run-time on the external battery pack was only around 25 minutes (bluetooth connected, screen max. brightness). There was probably plenty of charge left in the 750mA.hr cells - but the voltage drop meant that it couldn't be used. As the voltage dropped, the Nüvi became unstable - rebooting and entering all manner of strange states sad

With all this brain-storming we will eventually figure the best way - great stuff!!

What you report just confirms one of the problems. With the standard cable it goes to Mass Storage. My AA batteries are 2300mAh so I hope to get a better life (I suspect AAA may not have what it takes).

I have solved the connection problem but still need to improve it physically.

I still need to trial reducing initial high voltage. I have the zenner but need to get the time to try it.

The BIG trip is still 6 months away so I have time to play yet - and watch for other ideas.

There have been some very interesting product suggestions I can fall back on if it gets ugly in the battery box and makes magic smoke!

Charging

I haven't had time to read all the posts since my last input but I disagree that the car adapter is a dumb converter. I believe it has circuitry to end the charge cycle and prevent damage to the battery. I know my Li-ion cell phone car charger has circuitry since it causes static in the radio which I realize may be just a switching converter but I believe is more than that.
Since these batteries are so expensive and have to be replaced by Garmin, why take a chance of ruining it?

Charging circuitry is in the device, not in the adapter!

Mike107 wrote:

I disagree that the car adapter is a dumb converter. I believe it has circuitry to end the charge cycle and prevent damage to the battery. I know my Li-ion cell phone car charger has circuitry since it causes static in the radio which I realize may be just a switching converter but I believe is more than that.

Nope. The charging circuit it built into the Garmin just like it is built into your cell phone. The auto adapters do nothing more than provide a voltage at a minimum and possibly configure the USB data lines to indicate to the device what is plugged in or to allow the unit to not go into mass storage mode. But other than that, all the charging circuitry (the charging brains) are in the device itself.

PT

--
Garmin nüvi 200 (my first GPS), 780, & 3700 Series. And a Mac user.

.

Mike107 wrote:

I know my Li-ion cell phone car charger has circuitry since it causes static in the radio which I realize may be just a switching converter

You're possibly spot-on with that hypothesis!

My Nüvi 310 'Vehicle Power Cable' (010-10723-06) contains the following components:

--
------------------------ Phil Hornby, Stockport, England ----------------------               http://GeePeeEx.com - Garmin POI Creation made easy           »      

Still Nope...

Hornbyp wrote:

You're possibly spot-on with that hypothesis!

My Nüvi 310 'Vehicle Power Cable' (010-10723-06) contains the following components: {snipped}

Still nope. All of those are nothing more than a power supply to get the correct voltage off your "12V" auto system for your Garmin and some filtering. None of those components are the "smart" ICs required for a properly designed Li-Ion charging system.

So again, the charging smarts are in the device itself.

PT

--
Garmin nüvi 200 (my first GPS), 780, & 3700 Series. And a Mac user.

That's not what I meant...

Guttermouth wrote:

Still nope. All of those are nothing more than a power supply to get the correct voltage off your "12V" auto system for your Garmin

It was the 'static' part, I was referring to.

--
------------------------ Phil Hornby, Stockport, England ----------------------               http://GeePeeEx.com - Garmin POI Creation made easy           »      

oopsee

Hornbyp wrote:

It was the 'static' part, I was referring to.

Oops, I see what you mean now. Sorry about that. wink

PT

--
Garmin nüvi 200 (my first GPS), 780, & 3700 Series. And a Mac user.
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