Battery charging time question.

[justlookin]

Hi Group, wondering if anyone can give me an idea if i'm on the right track
for a charging time on a handheld radio battery.
It's a kenwood copy and the "fast" charger cradle says 14.5v input at
800ma and it lists the output at 9.4v at 850ma both DC. The battery is a
NiMh at 1500mah at 7.2v. Now the interesting part is that the supplied
plug pack does not meet the input listed on the cradle, it is 12v dc at
300ma, so i take it if the plug pack was up to spec the fast charge time
would be just under 2 hours, but with the supplied plug pack at 300ma i
would be looking at around 5 hours to charge ??
Thanks for any help !
Steve.

 

[Phil Allison]

"justlookin"

Hi Group, wondering if anyone can give me an idea if i'm on the right
track for a charging time on a handheld radio battery.
It's a kenwood copy and the "fast" charger cradle says 14.5v input at
800ma and it lists the output at 9.4v at 850ma both DC. The battery is a
NiMh at 1500mah at 7.2v. Now the interesting part is that the supplied
plug pack does not meet the input listed on the cradle, it is 12v dc at
300ma, so i take it if the plug pack was up to spec the fast charge time
would be just under 2 hours, but with the supplied plug pack at 300ma i
would be looking at around 5 hours to charge ??
Thanks for any help !

** Far too many unknowns in your story.

Just try it out and see how long it takes.




....... Phil

 

[Allan]

Hi Group, wondering if anyone can give me an idea if i'm on the right
track for a charging time on a handheld radio battery.
It's a kenwood copy and the "fast" charger cradle says 14.5v input at
800ma and it lists the output at 9.4v at 850ma both DC. The battery is a
NiMh at 1500mah at 7.2v. Now the interesting part is that the supplied
plug pack does not meet the input listed on the cradle, it is 12v dc at
300ma, so i take it if the plug pack was up to spec the fast charge time
would be just under 2 hours, but with the supplied plug pack at 300ma i
would be looking at around 5 hours to charge ??
Thanks for any help !
Steve.

I think you may have a problem, if the charger cradle says 800 ma then the
12v 300 ma will be to small, and may fail.
Also the lower voltage MAY mean you wont get a full charge, but that's going
to depend on the type of charging circuit it has.
I would be tiring to get a 14.5 volt Power supply with a current rating of
at least 850 ma.
If you have a DMM take some measurements and see how much current it does
draw when charging a flat battery..
Allan

 

[justlookin]

Thanks Allan,
I had a quick look with the multimeter at the contact
points on the cradle with the plug pack attached but no radio in the cradle,
it's sitting over 22volts and the same straight on the plug of the pug pack,
so i guess t's fair to say it's unregulated ! When i get a chance i'll have
a look inside the cradle and see whats there, i've done a google on this
type of radio and theres been a bit of discussion about them in the uk with
a lot of them being fakes, the cradle led is supposed to go red for charging
and green when complete, but one person said their led was only 2 pins not
3. Anyway, i bought the unit with low expectations as it was from HK, i just
mainly want to not over charge it, I gave it about 5.5 hours on friday and
the radio does and has worked well on 5 watts, but i think a regulated pack
would be a definite !
Thanks,
Steve.