GPSrChive Discussion Forum

Hello,

Would a 12 Watt charger be adequate to charge a 67?

Thank you

Yes, any good quality USB charger can charge the GPSMAP 67. Note that the charging speed is determined by the GPSMAP, not by the charger.

JungleJim wrote: Sat Aug 31, 2024 8:34 am Note that the charging speed is determined by the GPSMAP, not by the charger.

The sentence expressed is a certain simplification, the charger parameters affect the charging time.

Using a charger with a higher charging current than recommended will not reduce the charging time,
but using a charger with a lower charging current will extend the battery charging time.

The charging time depends not only on GPSMap but also on the charger.

Przekątny wrote: Sat Aug 31, 2024 10:17 pm The charging time depends not only on GPSMap but also on the charger.

That's very true, but it's little more complicated.
There are different power supply standards, to put it simply, if both charger and charging device doesn't suport Power Delivery (PD) standard, maximum charging power is limited to 7.5W (1.5A on 5V), even with 12W charger. Both charger and device exchange information to set proper charging voltage and current.

Charging with higher power means higher current (up to 5A with 100W) and higher voltage (eg 20V with 100W charger). Yes, that means USB charging cable should be better - should support higher charging power.

I'm afraid GPSMap has basic USB-C port without PD, so, you can use any charger even with more power, but don't expect quicker charging.
For example I'm charging my GPSMap67 with 60W charger from my notebook, and charging time is not much different than charging with 10W charger from another device.

In my opinion it is not complicated.

Przekątny wrote: Sat Aug 31, 2024 10:17 pm The charging time depends not only on GPSMap but also on the charger.

Assuming: maximum device charging power 7.5 W (1.5 A 5 V) we will use a 650 mA 5 V charger
it will turn out that the charging time does not depend only on GPSmap.

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When using a 650 mA 5 V charger, the charging time will not be longer than twice, because the maximum current of the battery is charged in the first charging phase, then the internal resistance of the battery increases, which limits the charging current.

Przekątny wrote: Sun Sep 01, 2024 12:33 pm Assuming: maximum device charging power 7.5 W (1.5 A 5 V) we will use a 650 mA 5 V charger
it will turn out that the charging time does not depend only on GPSmap.

Yes, of course, I've just said I agree with you - maximum charging time depends on capabilities of both sides: maximum current which charger can send, and maximum current which GPSmap can receive. But up to limits of the nominal High Speed USB Charge (with no DP) limit 7.5W/1,5A or so - that's the hint.

For example, take a look, official Garmin High-speed Multi-charger, it's good measure of garmin devices charging limits:

Spoiler

https://www.garmin.com/en-US/p/142325

Input : 10-30v 5.4A max
Output USB : 4.75-5.25v 2.1A <- that's little more output power than 7.5W