1st battery charge on NiMh packs

[Baddon]

Just got 2 new NiMh 3300 packs, been out of the hobby for over 20 years, so please excuse the newbie question.

 

The charger I have has options to charge at .05A, 1A, 2A, 3A or 4A.

What is best for life of battery (is there something better for its start of life ?)

ie is it better to slow or fast charge, esp from new or ever so many cycles?

What will expected charge time be on each rate (is there a calc I can do to know so if I have a limited time I will use a certain rate rather than best for battery life) ?

 

I did search back about 4 pages before posting this as I am sure it has been asked before, so apologies if its rehashing an existing question.

Edited November 17, 2017 by Baddon
added another question

[GooneyBird]

Modern NiMH packs are pretty sturdy things. It's a great example of 'mature technology', IE: all the kinks have been worked out.

First charge: Go for the 1A charge, just to gently wake it up. Run it until the speed noticably drops. (Or you get bored, whatever comes first really), then put it back on the charger for the full 3A or 4A.

Math time! Actually quite easy. You've got a 3300mAh battery. Assuming it's completely flat-dry (which it will never get), you need 3.3A for 1 hour to charge it back up. However, most NiMH packs are actually a bit underrated. I have a 3000mAh pack, that routinely takes ~3500 mAh in charge. And that's with the cutoff set at a generous 1V per cell. On the other hand you'll never run it completely dry. Most (semi)-modern ESCs have a cutoff to protect the pack.

One thing to note: is your charger compatible with NiMH? A NiCad charger cannot succesfully detect the delta-peak of a NiMH pack (as the voltage drop to indicate a full charge is much more subtle).

[Baddon]

26 minutes ago, GooneyBird said:

One thing to note: is your charger compatible with NiMH?

Thanks for your reply,

In answer to your question above, Yes, says so on the charger 

Its an Origin Radient, NiCd & NiMH AC/DC 4A Peak Detection Charger. Clearly states on it NO LIPO though.

[Backlash]

1 hour ago, GooneyBird said:

Math time! Actually quite easy. You've got a 3300mAh battery. Assuming it's completely flat-dry (which it will never get), you need 3.3A for 1 hour to charge it back up. However, most NiMH packs are actually a bit underrated. I have a 3000mAh pack, that routinely takes ~3500 mAh in charge. And that's with the cutoff set at a generous 1V per cell. On the other hand you'll never run it completely dry. Most (semi)-modern ESCs have a cutoff to protect the pack.

 

The mAh rating on the pack is the discharge capacity..

Sometimes you will get lucky and get more mAh out of you battery than its rating and then with others  (like the cheap eBay packs) you wont get any where near the pack rating..

Generally you will need to put 110-120% of the rated capacity back in to reach full charge, so that's probably why you are putting 3500mAh back into your 3000mAh battery