Battery Charging Times? Whats the math?

[Rabbit]

Trying to find some information on charging times for wall chargers.

Mind you, i dont plan to use the wall charger for very long not will i be using this battery until i upgrade to a better customer battery & duratrax piranha charger.

Its an 8.4v 600mah Mini for an MP5SD6

Wall charger:
Input: AC 110v50HZ
Output: DC 8.4v250mA

After reading another post the math worked out to about 9 hours? which doesn't sound right, I was guessing around 5 hours or so

[Boyso]

Even 5 hours seems to be way to much.

The output is 250/hr.

600/250 = 2,4

You then need to multiply to a factor I actually can't find right now due to the battery pack loosing some mA.

2 hours and an half would be a good charge to start with until you get a decent charger.

At least, you'd be sure not to bust your battery.

PS : A better battery would be good too, 600 mA is quite small. (www.cheapbatterypacks.com)

[Gunny_McSmith]

Originally Posted by LastSpartan

Even 5 hours seems to be way to much.

The output is 250/hr.

600/250 = 2,4

You then need to multiply to a factor I actually can't find right now due to the battery pack loosing some mA.

2 hours and an half would be a good charge to start with until you get a decent charger.

At least, you'd be sure not to bust your battery.

PS : A better battery would be good too, 600 mA is quite small. (www.cheapbatterypacks.com)

the factor is around 1.3/1.4 for NImh and NIcad batts....

[kalnaren]

1.4 is probably a little high for NI-Mh, you'd be safe with 1.2.

[Boyso]

Alright, thanks.

Soo.

600/250*1.2 = 2.88 hours = 2 hours 52 minutes

Smart charger is still a smart idea.

[ThunderCactus]

That still seems REALLY high, I charge all my batts in around an hour and a half or less... But that's with the pirahna your planning on getting (good choice btw)

[kalnaren]

No way a 250 Mah charger will charge 600 mah in under 2 hours. Personally I charge batteries around 1C, so it takes just over an hour regardless. My charger has it's auto shutoff set at 120 minutes. I don't want to leave batteries charging longer than that.

[venture]

You have the math answered correctly, Mr. OP. Use the factor to add the extra time and you should be safe. Also do a physical check - the battery should not exceed 80º C when charging. If you don't have a temp. probe (and you probably don't), just use your arm. If the battery is uncomfortably warm/hot on the inside part of your arm, then it is time to stop charging.

[Boyso]

Originally Posted by ThunderCactus

That still seems REALLY high, I charge all my batts in around an hour and a half or less... But that's with the pirahna your planning on getting (good choice btw)

what's your charger/battery?

It depends of your charger's output.

[Rabbit]

Wow ok...so theres a few different answers but most people said around 1.2 to 1.4 hours i was assuming?

[kalnaren]

1.2 - 1.4 is the multiple. (<battery capacity> / <charge rate>) * 1.2.

[Boyso]

Originally Posted by Remylebeau

Wow ok...so theres a few different answers but most people said around 1.2 to 1.4 hours i was assuming?

Originally Posted by LastSpartan

Alright, thanks.

Soo.

600/250*1.2 = 2.88 hours = 2 hours 52 minutes

Smart charger is still a smart idea.

Still, check if the battery gets too hot with the inside of your arm.

[The Chad]

I think there is already a thread on this:

http://www.airsoftcanada.com/showthr...battery+charge


Hopefully that helps.

[show_stopper35]

i hate math lol
thats y im just getting an auto cut off charger

[Rabbit]

worst case scenario, can i use this wall charger to charge nimh batteries as well?
the 8.4v 600mah is a nicad. Actually lasted me a whole day playing with it