secret_squirrel

Hi all,

I have been pulling my hair out trying to cycle NiMh batteries and I have basically given up on my charger. I have a VistaPower Q6320 AC/DC and I absolutely hate it for NiMhs. I recently switched from NiMhs to A123s for my Rx batteries and the charger does fine in this battery chemistry. I believe something is wrong with the NiMh/NiCd part of the charger.

My Tx batteries and a few smaller planes, as well as my gas ignitions, use NiMh batteries (mostly 2000 mAh). I need a RELIABLE NiMh/NiCd battery charger/cycler for both the field and home. I am really interested in one that properly detects the NiMh delta peak and pack voltages because I truly believe that is where my current charger fails. It constantly false peaks. I am willing to pay if the charger can properly cycle and charge NiMhs and of course other battery chemistries are fine but I am more concerned with the 4/5 cell NiMhs. I am also interested in at least a two port charger.

A apologize if this has already been posted somewhere, I sorted through the recent posts but most seem to be looking for Lipo chargers.

Any assistance is greatly appreciated.

I know there are people out there still using these batteries, what has worked for you?

Thanks in advance,
Dan

flyinwalenda

My Feedback: (5)

A 2 port charger with the features you want will cost around $200.00.
This is a nice ,easy to use single port charger that will cycle your Nixx packs plus charge Lixx and Pb batteries as well.
http://www.horizonhobby.com/product/...ger-p-kxsc1002

secret_squirrel

What would be your suggestion for two ports. Anyone still using the triton and/or accu-cycle elite? I used to love the accu-cycle elite. Went to the Vista Power when it burned out for Life compatability. Now that I don't need Life/Lipo, a rock solid two port NiMh carger is what I crave ;-)

P-40 DRIVER

Give up on the idea of fast charging your NiMH batteries, use a 1/10C charge and pull them off when they start to get warm. You can discharge them using your current charger to check for condition. I use a Cell Pro Multi4 for charging receiver batteries,. You would be hard pressed to find a better charger for the money. a lot of your issues may come from your charger wiring if its not up to spec. Hobbico makes a good 2 port NiCad/NiMH cycler but its useless for anything else. Nimh batteries when fast charge need to use temp cut off to actually work well, the Hobbico has that feature. Good luck, Nicads are much better suited to fast charging. LiFE seem to be the way to go these days. NiMH, you seem to always false peaking or cooking your batteries

secret_squirrel

I dont fast charge my NiMhs. usually 1A or 500 Mah. Will the Hobbico two port charger you talk about charge also. SOunds like exactly what I need? I usually charge on the way to the field and agree that temp cutoff is optimal. What os the brand?

P-40 DRIVER

Try this, should answer your questions

http://www3.towerhobbies.com/cgi-bin...&I=LXEYD4&P=ML

P-40 DRIVER

These are probably the best chargers on the market.

http://www.usastore.revolectrix.com/...pro-Chargers_2

jetmaven

Go to hangtimehobbies.com and learn all about charging NIMH's before you buy anything .Treat them right and they'll treat you right .

secret_squirrel

Funny, after a whole day of agonizing over this, the accu-cycle elite is what I had before my q6320. Never popped into my head today, not sure why because I loved that charger. It won't do life, but like I already explained, don't need life charging. I ordered one with two temp sensors. Thanks.

secret_squirrel

All my batteries are NoBs batteries....exactly why I have been pulling my hair out. I know he makes a good product and my charger is crap. Anyway, I can't be around my batteries while they charge at 1/10C to see if they get warm during cycle routines. Hopefully the accu cycle elite with temp probes will solve my problem. If not, I am going back to nicds.

Rodney

That is the nice thing about charging Ni.xx batteries at 0.1C; you do not have to be around to watch them. If you leave them on charge to long, no harm as the heat build up is so slight there is no damage. Also, at 0.1C charge rate, if you leave them on for at least 14 hours you are sure that all the cells have been fully charged and should you forget and leave them on an extra day, no harm.

qwerty3

I've had a similar experience with NiMh packs - the 'fancy' charger will false peak, and shut off way too soon. A cheapo Hobbico 'Fast Field Charger' seems to do OK- but the overnight wall-wart type charger is probably best. Especially with a new NiMh pack, expect to cycle it 4 - 6 times before it comes up to capacity. It may require manually charging with one device, then discharging on another. A good LiFe pack is a lot less hassle, IMHO.

jetmaven

I put 2000 mil Eneloops from NoBsBatteries in my old reliable Futaba 8 UAP. I've found them easy to care for . Well worth a few bucks more.

049flyer

My Feedback: (18)

Any charge rate higher than 1/10 c is considered a fast charge and should be avoided with most NIMH/NICAD cells. Some cells are more tolerant of fast charging than others, only testing will tell you for sure how fast a given pack can be charged. To be on the safe side use 1/10 c.

Therefore, for a 500 ma pack, you will need to charge at 50 ma for 12 hours or so, a 1000ma pack will charge at 100 ma for 12 hours.

Many quick chargers will not charge at this low of a rate and many will automatically shut off long before the 12 hour charge is complete. Peak charging will not work on a 1/10 c charge rate. Use a charger designed for constant rate over night charging.

John_M_

Get yourself an iCharger 208B, or a iCharger 306B... if your really into big electrics, then get the iCharger 3010B... I use a iCharger 208B to charge all my receiver and servo buss batteries... works great as a field charger too, but you're limited to the cars 12 volt starter battery voltage, so consider getting a decent DC power supply... with NiMh you have to slow charge (none peak detection) for the first few cycles to establish the full capacity of the cells, I use just a std wall charger at 500 mAh, once they've been brought up to full capacity, I use the iCarger from there on... its a great little charger!... the 306B is 20 bucks more than the 208B, and the 306B comes with a power balance board thrown in.


http://www.progressiverc.com

John M,

secret_squirrel

well, I purchased Eneloops and according to HangTime Hobbies they come pre-formed. Will still take it easy on them for several cycles. Anyway, after I receive my Accu-Cycle Elite, I will have it, a wall wart, and my A6320AC. Tons of options. Dealing with both brand new packs and old packs that I need to cycle. I used to love the accu cycle elite. Like I said, gave it up for a fancy charger. Now I have both.

secret_squirrel

I agree with you on Niacds. Not so sure heat is good for NiMhs though. I also understand trickle charging them is not as good as Nicds. I used to trickle my Nicds all the time but I think NiMhs are different. Who am I to say though. I leave them on till they start to heat up and then take them off.

secret_squirrel

yes, my new packs are Eneloops. I have some old cells that need to be cycled to see if they are any good though.

P-40 DRIVER

Long live the NiCad battery, It is a much better solution then most, and has few drawbacks except for weight. They are still in my future until they quit making them. A goof proof battery if there ever was one. Those Sub C's would take a lot of neglect and abuse and still do the job. My Makita drill used them, run everyday, for years, fast charged, run completely flat sometimes. LiFe batteries are going to be, the go to battery for most people as time goes on but I still think NiCad's should not be ruled out quite yet. Those Eneloops have a future but not as receiver batteries.

secret_squirrel

Sounds like we are on the same page. I absolutely love my A123s so far. Of course they are new but 1) when I got them, took about 30 minutes to charge and they were in my plane doing their job. No forming charge crap :-). 2) easy to charge, and you can see each cell, that is what I love. 3) I don't even put a dent in them at the field.

The only thing I don't like is their discharge curve and size. And I need to do some more research to figure out how to tell when they are bad.

jmiles1941

I use hitec x4 it charges all types of batteries little pricey but it does a great job just my 2 cents worth

P-40 DRIVER

The life and proper use of NiCads is so well known, that we take it for granted. The LiFe batteries will become that way; as well, as we use them more and more. They just have a different set of rules to follow. I think their done when they will only discharge to 80% of capacity just like any other battery. As for catastrophic in flight failures; who knows how that's going to pan out in the long run. I suspect junking them every 2-3 years is your best bet to avoid failures. I would also cycle them every 3 month or so to check capacity.

John_M_

My inlaw and I both dispose of our a123 and NiMh cells at the end of a flying season... we get about 60-70 flights a season, maybe a bit more if weather and time permits... the batteries are cheap enough now days, its not worth the hassle of predicting when good is good enough... back in the early days of NiCad's I had more memory issues causing sudden voltage drops, than I care to admit too... I was even cycling them regularly with an Abacus battery cycler... of course, A123 LiFe and NiMh don't exhibit memory issues, but I still at the end of the days flying discharge them to a safe voltage, and then slow charge them back up to storage voltage until the next weekend of flying and then hit them with a faster charge to bring them up to full capacity just before going out flying again... after 3 flights, they're charged back to a full charge again... I also vary the charge rates, just so not to get into consistent ritual of managing the batteries, mix it up keeps them alive and kicking.



John M,

bjw4072

My Feedback: (6)

There is probably nothing wrong with your existing fast charger. It is false peaking because the cells are not balanced.
As has been mentioned above, the best way to charge NiMH packs is with a simple constant current 1/10C charger.
Use this non-peak charger at home before flying. Then if you need to occasionally fast charge at the field your peak
charger will probably work fine as the cells tend to balance out when most of charging is done at the
constant 1/10C rate.
If you are using 2000mAH packs as I do, Maxx Products sells a charger CH96N for $18 that will charge 4 or 5 cell packs
at 200mA.

chuckk2

Have you cycled the batteries several times?
I found that that can help.