Charging Rate vs Battery Power

[skom25]

Hi,

Question is quite strange and probably answer is "No" but:

I have SkyRC E450 charger and HPI Plazma 3300 NiMh batteries.

Charger has battery type selection and charging rate 1/2/3/4A. During charging, LED indicates level of charge.

Red: 0-25

Red Blinking: 25-50

Yellow Blinking: 50-75

Green Blinking: 75-100

Constant Green: 100

I read somewhere, that charging with low Amps is better for batteries, so I charged them with 1A, because I have time to do this. Strange fact that there was no "Yellow Blinking" part. There was "Red Blinking" and then "Green Blinking". I was sure that there is error in manual and yellow Led does not exist.

Yesterday I was little in hurry, so I decided to go with 2 Amps. I was surprised, because for the first time I saw "Yellow Blinking" led. Well, strange...

Today I ran one battery and from beginning, I had feeling that car is much more powerful. Max speed and initial bite was much better.

Question is:

Is it possible that with 1A batteries were not fully/ properly charged? I am not sure about my observations today but also I did not expected anything, so there was no autosuggestion in that topic.

What do you think?

 

 

[sosidge]

A fast charge is at 1C - 3.3A in your case but 4A would be my choice with that charger. Although if it is a charger that ONLY has LEDs on it, I would choose not to use it at all and replace with a charger that gives proper feedback on the voltage of the cells.

1A is a nothing charge, too fast to be a trickle charge (which would be used in industry or in "dumb" chargers where there is no need for they to cut off), too slow to be a fast charge. So I'm not that surprised that the charger is struggling to find the right cutoff.

[skom25]

Thanks!

I wanted something idiot proof at start and E450 seemed to be good choice. I will go for something better in future.

[Willy iine]

Is that like my Dynamite charger I got recently?  (like a rebadge version?)

 

Anyway, on that charger I only use the 3A setting for 3000mAh and 3600mAh NiMH batteries.  And if you want to keep the battery healthy for a long time, I suggest you only run 50% of the capacity and allow the battery to rest until completely cool (or rest overnight) before recharging.  What I usually do is run the car for only 5 min and then charge the battery after full cool down to see how many amps it will charge.  On this charger you'll need to go by charge time.. meaning if your charge time at 3A for 3000mAh is 30min, then you used about half of the capacity.  With a 5 min drive, depending on motor and driving, you should get about 15-20min charge time before full charge.  Then you know you can drive up to about 10min with 50% of the charge capacity remaining, for example. 

You can peak charge at 3A too just before running your car if you want to get the highest voltage without damaging the batteries.  I usually have a battery charged at all times, then peak charge it 10-15min before running the car.  I also recommend you charge in room temps as much as possible... minimum 50F - max 85F  range... otherwise your cells might not peak normally.

[El Gecko]

Sounds just like my charger, except I've always gotten yellow occasionally when the battery is really depleted.

However I too have been making the mistake of charging my NiMHs at too low of a setting. Whereas NiCds love trickle charging, and quick charging degrades them faster, it seems that NiMHs are the opposite, up to a point.

So I've started charging all NiMHs at 0.5-1C, basically as close to 1C as I can get, since my charger only goes up to 4A like yours (maybe my 5000mAh's don't get quite as full, but it's still within the range).

I only go up to 1C because I don't like how hot the cells get if they're over that (I don't charge a 2000mAh at 4A, for example, and I would charge a 3800mAh at 3A).

I can't tell if it makes much of a difference for power or runtime, although I haven't been very scientific about it. The weather here is all over the place lately, and NiMHs are really sensitive to cold weather. A pack that did well on a warm day a few weeks ago didn't work as well on a colder day a week later, and it was charged the same and used in the same car.