Hello to all.

I just started with the hobby and I just acquired new 8cell 720 mah NiMhs. Therefore I am currently in the market for a charger/cycler. The trouble i'm running into is that it seems most products in the market are either a cycler or a fastcharger, not both.

I am leaning towards the Supernova from FMA. It was mentioned in the (battery clinic) website that you could in fact "fool" the charger into charging at C/10 rate. Did I understand this correctly?
Any comments/hints appreciated...


Thanks,

Noel

I suppose you mean <a href="http://gnv.fdt.net/~redscho/" target="_blank">Red's Battery Clinic</a>?

Quote from Red's Battery Clinic:
As originally conceived, the SuperNova was not intended to perform C/10 or overnight charging, but Fred Marks of FMA Direct suggested something I'll pass on to you: if you select the lead-acid battery, you really don't have a peak-detect circuit in effect; you can set the average voltage for your pack and the C/10 charge rate, and it will continue to charge indefinitely. I tried this with a 6-cell 1700niAh pack The voltage was set at 8, and the charge rate was set at 0.2 amp (200mA). You can set the current only to 100 mA, so the 0.2 was as close as I could get to the 0.17 amp that I wanted. Under these conditions, the SuperNova did work, so this is an option you might want to try.

It seems you can do it by putting the charger onto lead acid at C/10 rate. This way the peak detect doesn't take effect. Personally I've never tried it but I'd love to hear from anyone who has!

Ben C

PS. It is a very good charger. I would definately recommend it!

[This message has been edited by Ben C (edited 06-08-2001).]

consider also that the lowest setting of the Supernova 250S is 100ma (.1 amp) so you may not be able to get down to a C/10 rate on some of the smaller batteries (270mah, 110's, etc.).

I have one of these chargers and for the price I love it!

Steve

Thanks for replying so quick guys.

So if I understand this correctly, the Supernova can (initially) charge my 720Mahs at C/7 (if there is such a thing) or 100mah in 7 hrs.

I know most people would rather initiate the batteries at C/10? 7hrs is close enough I guess.... Hopefully there no long-term effect to the batteries. What the heck. Im sold!

Noel

I'm extremely pleased with my Supernova. I've decided to abuse the heck out of a few NiMH packs and see how long they last. I've been charging a 600mAh NiMH pack at 1.2 amps for about 25 cycles now, and it just keeps bouncing back 100%. I plan to charge a 720mAh NiMH pack at 1.4 amps. It's great to be able to charge a NiMH pack in 30 minutes. With the Supernova's advanced circuitry, the packs don't even get warm when being charged at this rate. If this pack dies prematurely, I might back off to .6 amps. But I really don't believe it is necessary to "baby" NiMH when you have a quality charger like the Supernova.

There is no need to "fool" the charger to make it charge at 100mA. Just set it to manual mode instead of auto and program it for precisely 8 NiMH 720mA cells and a fixed charge rate of 100mA. It's already designed to do it. Easy!

By the way, I use mine, (the Simprop clone version) on auto for those very same cells and it works perfectly every time. The current maxes at about 1.3A then tapers down just before peaking. They come off hot but never so hot as to vent or damage the shrink wrap.

Not to take anything away from the Supernova..I'm sure it is a good charger. I just happened to purchase the Dymond RC version. It is quite a bit less money and is all the charger I need. Wanna talk service ?

I purchased mine in January. I had a problem with it in May three days before Memorial Day weekend, and I call Helmut at Dymond RC. I said the warranty is six months, right ? He says "don't worry, we replace them after that too". I asked about getting one sent out right away and he said "no problem we send one out today, just send us the old one with a letter of description of problem" . So I get my new one on Saturday before the big weekend . Thanks Helmut and Dymond RC !!

Al

Gerald does your charger let you actually set the 720 exactly ? I have the version made by Dymond and was told all the three are same chargers. FMA's Dymond's or Simprop's versions of this charger are all made by same company.
But mine does not have the 720 as an option.
700 and then 750. Any thoughts on this ?
Or perhaps they are not all the same ?

Originally posted by Gerald:
There is no need to "fool" the charger to make it charge at 100mA. Just set it to manual mode instead of auto and program it for precisely 8 NiMH 720mA cells and a fixed charge rate of 100mA. It's already designed to do it. Easy!

By the way, I use mine, (the Simprop clone version) on auto for those very same cells and it works perfectly every time. The current maxes at about 1.3A then tapers down just before peaking. They come off hot but never so hot as to vent or damage the shrink wrap.

Vicman

I presume the 720 you want to set is the pack capacity ? If so, you can set it the next stop higher and it will still peak correctly. No problem.

Al

Originally posted by Al P:
Vicman

I presume the 720 you want to set is the pack capacity ? If so, you can set it the next stop higher and it will still peak correctly. No problem.

Al

Thanks Al, I do have 720 pack and I did setup
the charger to charge it as 750. I was going to find out if the charger made by Simprop is actually different them mine and if it will let you setup exactly the 720.

i, too, have an fma 250S that ime vrey pleased with. works like a champ. that being said *begin shameless plug* you could build yourself a slow changer for like $10 from parts you can get at radio shack or any better supplier. have a look at the article i wrote at http://www.ezonemag.com/articles/200...er/charger.htm - its just the ticket for doing this type of slow charging and equalizing of packs. *end shameless plug*

Hi,

if the 720 mAh NiMH are from Sanyo or GP then it is officially ok to quick-charge them up to 1C=720mAh once they are formed at C/10. I have some Sanyo Twicell 700 packs (just the same but have button top to be used in consumer stuff) and they work great. But be sure to have a NiMH graded peak charger (not an older NiCd graded one).

Regards, Jochen

How do you tell if its Sanyo in the first place? The batteries I got were dark green then it says "720 mAh JAPAN FCH". At the "-" end it says "HR". other than that nothing else...

Noel

Same batteries like I have, kind of hard to say what they are. I guess shouldn't be bad whatever they are if they are made in Japan.

Originally posted by CheapDad:
How do you tell if its Sanyo in the first place? The batteries I got were dark green then it says "720 mAh JAPAN FCH". At the "-" end it says "HR". other than that nothing else...

Noel

Hi CheapDad:
Let me try to lean you another direction.
The little jeti $35 DC charger is rated for 4 through 7 cells.
Well it charges my 3 packs of 8 cell 720 ma MiNH and all of my other size NiMH and NiCD packs beautifully. Almost all of my packs are 8 cell. Been using it for about 8 months now and not even a hickup.
My 2 cents Put this towards your new charger. Der Zip