Overcharging battery

[W1WH]

Does anyone know of the TT1 has an overcharge protection circuit? Is it possible to overcharge the battery?

 

[danjreed]

I doubt it.

 

[ruwafl]

i would seriously doubt that it would not have a overcharge protection circuit. not that i'm in the know about the tomtom circuitry, but i deal with lithium batteries in my r/c hobby. have you ever seen what even a small lithium battery can do when over charged? lithium batteries are a good technology but a lithium battery will not tolerate overcharging.

 

[Wiley]

TomTom has admited, rather candidly, that they have had problems.

Does anyone know of the TT1 has an overcharge protection circuit? Is it possible to overcharge the battery?

TomTom replaced my battery-blown One v2, with virtually no hesitation. The two service people that I spoke to in September '07 remarked that they had been seeing a number of units coming back with batteries that had died prematurely. They believed that the issue was/is caused by too frequent charging by users. They confessed that the majority of "Refurb" units being returned to the marketplace had battery related problems when first sold as new.

I was encouraged (or warned) to not leave my One plugged into a charging source for an extended period of time. That little off-the-cuff comment sounded to me like they didn't have much faith in any charge-limiting circuitry that was currently built into their units. I don't know how big the battery related returns were, but the TomTom folks that I spoke to said that they were seeing a trend upward at that time, as the number of users increased.

I've decided to play it safe and monitor the battery level on my TomTom only once a week. I try to keep it charged up to at least 70%, as Li-Ion batteries don't like to be totally discharged either. It's a little perturbing that battery and battery-charging technology hasn't simplified our life as much as we might have hopped for.

 

[flyer1024]

The car charge cord or the unit itself has overcharge protection, not sure which.

If you check your battery status when plugged into the charge cord it will show "charging" when charge is actual happening. When fully charged this notification disappears.

the number of battery failures most likely is caused by users over discharging their batteries. Lithium batteries are notorious for failing if over discharged. Also lithium batteries are a fire hazard if over charged so any manufacturer providing a device without charge cut off with lithium batteries would be taking serious risks.

 

[w5lx]

It's hard to believe that any modern piece of electronic gear would not have overcharge protection built into it. If it didn't, that would mean you would need to disconnect the cord from the cigarette lighter plug when not using the unit or it would overcharge and the battery would blow up from excessive heat (which is what happens when overcharging occurs). Just about all modern circuitry shuts off charging automatically when full charge is reached.

Does anyone know FOR SURE?

 

[bel4_20]

I'm sure that if it was any what of a hazard which it clearly can be there would be an overcharge circuit protection built in. I don't think tomtom wants those problems. (ie: injuries etc etc).

 

[Wiley]

TomTom replaced my battery-blown One v2, with virtually no hesitation. The two service people that I spoke to in September '07 remarked that they had been seeing a number of units coming back with batteries that had died prematurely. They believed that the issue was/is caused by too frequent charging by users. They confessed that the majority of "Refurb" units being returned to the marketplace had battery related problems when first sold as new.

The take-away I got from the TomTom folks was that frequent, prolonged recharging was the culprit...rather than "overcharging." What I recall hearing was "... only do a full recharge once a week, and do not leave the unit idling on the charging source for more than four hours. When the unit is powered down, the charge rate is significantly higher, and there is more heat generated by the battery."

In so many words, TomTom seems to be advising users to not leave the unit plugged in to a charging source when it is not in use, or otherwise needing to be fully recharged.

 

[danjreed]

Seems to make sense.

My unit seems to chage pretty quickly.

Proper battery cycles are the key to a good life.

http://en.wikipedia.org/wiki/Lithium_ion_battery

 

[Wiley]

That's a good reference... Some issues really stand out...

Proper battery cycles are the key to a good life.

http://en.wikipedia.org/wiki/Lithium_ion_battery[/SIZE]

It seems that Li-Ion batteries have a lot of issues that make you wonder why the small electronics industries are so infatuated with their characteristics.

For the consumer, the use of Li-Ion technology seems to be a losing game.

- Short life when compared to other battery types.
- A very small window for achieving efficient charging.
- Higher replacement cost than competing technologies.
- VERY SENSITIVE to environmental conditions. Heat from any source (the dash of a car, charging, etc) causes accelerated wear-out.
- Less durable mechanically.
- Subject of massive recalls by manufacturers...due to their potential to cause a fire.

Obviously, there must be some redeeming virtues of Li-Ion batteries. How could they be so pervasive in the hand-held electronics market if they didn't provide a significant advantage (AKA "profit incentive") to manufacturers. Unfortunately, that advantage doesn't necessarily transfer to the end users...us! Remember when you read this thread. It would be interesting to see how many users experience battery related issues before the end of 2008. Happy New Year!

 

[canderson]

It seems that Li-Ion batteries have a lot of issues that make you wonder why the small electronics industries are so infatuated with their characteristics.
(snip)...(snip)
Obviously, there must be some redeeming virtues of Li-Ion batteries. How could they be so pervasive in the hand-held electronics market if they didn't provide a significant advantage (AKA "profit incentive") to manufacturers.

The one primary benefit is to the industrial designer and the consumer -- these packs have substantially higher energy density (more poop per size and weight) than any of the previous (carbon, alkaline, NiCd and NiMH) packs did. They certainly aren't cheaper, and charging isn't as straightforward, either. They sure as heck aren't cheaper for the manufacturer to include in a product.

You want your products small and light but with a lot of battery capacity? Well -- this is where the technology has taken us so far. Best to live with the limitations, and be aware that the lithium technology is evolving and improving, too.

 

[Rick F.]

I would much prefer to have a device that is powered by a Lithium Ion battery than HGA or NiCad. My son is/was an engineer in battery developement and told me I should not let the LI battery get completely discharged, and it should give me a lot of yrs service. I've had my current cell phone for over 2 yrs using the same LI battery... and it gives me great service. Many other products are changing to Lithium/Ion since it gives us more power. Ryobi drills for instance recently came out with LI power. They're more expensive, but give the user more power with developing any memory of charge/discharge.