Does 9 + 9 = 18?

[woodturner]

The may sound silly, however will ask it anyway.

When looking at NiCad does two 9 hour charges, over two sequential days equal a single 18 hour charge? i.e TX, RX or Glow batteries.

[WayneBrown]

that depends more on the capacity of the battery, and the output of the charger..
If you have a 600mAh battery, and a charger that charges at 100mAh, a 6 hour charge is all that is required to put in the maximum of 600 mAh.
As many dollars as you've spent recently on parts, I woulda guessed you had bought a triton charger.. :shock:
At least it charges the popular chemistries, and you can see how much you put back in.

[ropes00]

I would say yes...and here's my thinking...

If your battery requires a full 18 hours to charge...the first 9 hour charge would put in what ever amount your charger is rated for. Taking in consideration some minute self-discharge, that occours with all batteries over time, the second 9 hour charge should "top off" the pack as if you had only dicharged it partially during normal use.

You may want to do a little more research on that topic, but that's my gut feeling on the matter.

[DavidH]

Capacity of batteries,
Output in amperage of charger.

For example a 2400 mah battery, charger with 200 mah output.
The charge would need to be approx 12 hours, but to fully charge it you would need to go 14 hours. You do this to make sure the battery is fully charged.

David

[woodturner]

Thanks for the replys. I understand if I use 2000 mah of a 2400 mah battery I'll need to replace the 2000 mah I've used.

What I was curious about, do you find it better to replace all 2000 mah at once or in two sessions of 1000 mah over a two day period.

What I didn't know is once you have the battery on a roll accepting a charge, does stopping in mid ful charge only to begin again next day affect the efficiency?

Thanks..

[Wyn]

Two 9 hour charges a day apart is roughly equivalent to one 18 hour charge. They'll be a little self discharge in between charges, but a day doesn't matter any since there should always be more mah put in than the battery is rated for. For example, at the C/10 rate, 10 hours would be ~100%. However, 14-16 hours is typically recommended, which is about 150% of rated capacity. There are efficiency losses, and the extra energy is wasted in the form of heat. As long as this doesn't get excessive in terms of time or temperature, it's acceptible. There is a FAQ at www.hangtimes.com that might give you some more info. Bottom line, I don't think it matters whether you spilt the slow charge over two days or not, which is probably what you suspected to begin with.

BTW - splitting the charge with a delta-peak detecting fast charger is not a good idea. If the charge is manually terminated shortly before it would have terminated automatically, the chager may overchage a bit the second go-round.