critterhunter

I've got some more info for you guys using this charger and/or Hobbyzone/Parkzone packs. I drained all my packs to near zero and then put them on at .1 amps to slow charge/balance them. This takes a good 9 to 11 hours, depending on the ma rating of the pack. I heard this was good to do with a new pack or after roughly 30 or so regular "fast" charges on a used pack to keep the cells in balance. It's supposed to allow a weak cell to recover and "catch up" to the stronger cells in the pack. Anyway, after doing this to all my packs and heading to the field they had only about 2/3rds the "horsepower" that they normaly do. Great, I thought I trashed my packs by draining them near dead and then slow charging. Well, after running them down about 2/3rds and then doing a normal charge (.9 amps for a 900ma pack, 1.1 amps for a 1100ma pack), I was relieved to find that they had their power back...AND it seems they are performing better and longer than ever. So, the slow charge does work but do yourself a favor and don't try to launch the plane after that. Drain'em down to half throttle cutoff and then recharge.

On the other hand, the slow charge did nothing for my sick Venom pack. As a matter of fact, the pack got worse and now doesn't even have enough power to launch the plane. I pulled off the shrink wrap and inspected them. I could see no shorts, dings, or dents that might indicate cell damage. I then checked each cell with a volt meter (though they were still wired together) and all the cells were around 1.3 to 1.4 volts a piece. I was surprised, as I figured the sick cell would should a lower volt reading. Maybe I need to disconnect all the cells to do this test...but I would figure any cell isn't being "helped" by the others so long as I put the volt meter on it's negative and positive ends? So, now I suspect that one cell is "faking" a full charge and is dropping in voltage drasticly as soon as a load is put on it. I was figuring I could probably run the pack down a few minutes and then re-check the cells? Or, should I remove all the cells and put a load on each one, seeing which drops the fastest in voltage via a small 1.5 volt light bulb or something? Need some ideas as I've never tried to diagnose a pack for a dead cell before.

critterhunter

Back to the topic of the amp drop from specified settings while charging. You said that this is due to the input 12v power source dropping in voltage and thus lowering the output amps to compensate. I've been experimenting with this and can find no relation to this drop. Sometimes it will lower the output amps from say .9 to .8, despite how high the source voltage is. AND...I also noticed that the charge will sometimes increase the output amps from say.9 to 1 amps. It appears to happen when the charging packs voltage has stalled. IE: It isn't climbing or dropping. Like I said, the charger appears to do this slight lowering or raising of amps on difficult packs near the end of the charge. This still leads me to believe that is has some form of charging logic in it that is trying to get the pack to the proper charge. If I'm charging smaller Sub A packs it may lower the output amps near the end of the charge (or raise it). However, after charging these and then charging some 3300 sub Cs I see no decrease or increase in output amps. My only other explaination would be that the output from the car battery isn't constant...and that it may (as it discharges) produce higher or lower input voltage to the charger. It's not a problem, just curious if it's charger logic or something other. This only happens maybe 1 out of 10 charges. Most of the time it stays rock solid on the specified charging amps.

Jim_Purcha

My Feedback: (8)

Great thread guys, I'm trying to understand this charger myself. Any way I'm using this to charge up the 8.4Volt 2100 Mah Nicad battery pack in the Hobbico Superstar EP. Plane crashed last year, repaired in a couple days. I tried it a couple of weeks ago after reading this thread. Set the unit as Nicad, 2100 MAh, 2.1 A, 3mv, no trickle charge. The battery charged up to 2100 Mah. took at least on hour, the pack was slightly warm. Went to the Wham Electric Fun Fly, got some help with it, flew great.

Last night, Set up is Nicad, 2100 Mah, 2.1A, 8mv, no trickle charge. The battery charged up to 1700 Mah. Reset the unit to 3mv and 0.5Amps. The charger turned off after approximately 280 Mah. I figure the pack now has a charge of 1700+280=19800 Mah. Does this seem correct to you?

Should I be using the trickle charge with nicads? Why not with NIMH?

I also find parts of the instructions difficult to understand. It needs some examples. I do not like the line that says "If this happens, just change either A, B, or C." Do you lower the value, rise the value, etc.

The guys at the field said they usually give the battery a quick charge just before the flight. Is this done at 4~5 Amps?

Help would be appreciated.

critterhunter

I haven't charged too many Nicads with it but when I did I was setting the M/V setting to something like 12 to 18 or so. Nihms work fine at 3mv, or set as high as 5 if the pack terminates too quick but 3 has never given me a problem. You want to detect the voltage drop quickly in order to prevent over charging a pack. Nicads do a much larger drop in voltage when peaked and thus the higher m/v settings. However, remember that if the pack wasn't drained near dead you won't get the capacity to reach the pack's rating as the battery is already "partly filled up" and thus the tank doesn't need as much gas to top it off. Once in a while (10 to 30 charges) I'll drain my pack to dead (to where the motor cuts off at the lowest speed and will no longer drive it) and then charge the pack. Write down the capacity it reaches and the peak voltage (VP) it reached. This will give you a good record of the packs condition. They almost always will charge to a higher capacity than the pack's rating when healthy. If you start seeing a big drop in capacity or VP numbers then the pack is sick. Drain it down near dead and do a slow charge (.1amps for a 1100ma pack, .2amps for a 2000ma pack, etc). This will take roughly 10 or 11 hours but helps balance the cells. The first flight after this slow charge might not produce the same power as the higher the charge rate it tends to give the pack more horsepower. However, I never do harsh fast chargers. I stick to .9 amps for fast charging a 900ma pack, and even only charge my 1100ma packs at .9 amps as they are pretty much the same cells. My 3300ma sub Cs I'll charge at 3 amps, but these are bigger cells than my sub As. Trickle shouldn't be used on Nimhs. Well, it can be but this charger doesn't go low enough for a safe trickle on Nimhs and Nimhs tend to not like a trickle anyway (can make the performance flat). Nicads do favor a trickle but I'm not sure if you're Nicads are large enough to use the LOWEST trickle setting on the Piranha. Others will have to chime in on that. Any other questions just ask and I'll try to help.

By the way, don't set the capacity at exactly what the pack is rated for. If it's a 2100ma pack set the capacity to 2500 to 2800. You'll often find the pack will have a higher ability than it's rating and if you set it for 2100ma the charge will stop there regardless of if the pack has peaked or not. Just play it safe and try to be around the charger when it reaches 2100 or so in capacity. If for some reason you don't have the m/v setting right the pack might overcharge and bad things could happen. I tend to put my hand on the pack and make sure it is never real hot. If it is stop the charge right away. I also like to watch the voltage and make sure it's making a steady climb. If it's stalled in one spot or keeps moving up and down this is cause to pay attention. It's probably nothing but the normal charge should be steady up and then steady down when peaked. Of course the voltage rises and falls when the charge amps cycle to 0 every minute or so. That's normal.

Jim_Purcha

My Feedback: (8)

10 to 18 mV seems kind of high. I was reviewing the manual for the Triton Charger, and the final pages gives a table of settings to use for various sizes of nimh, nicad and lithium packs. It recommends a 8~10 mV/Cell for delta peak for nicad batteries.

What has other modelers using nicads on the Triton experienced?

Allan Aguilar

I have this kind of charger for almost 2 years. I use this to charge my RC Car batteries NICAD and NiMH 2100, 2400, 3000, 3300 mah car packs, 2400 mah AA NiMH airplane packs, and 2/3 A receiver pack for nitro cars. This works perfect to me so no need to buy another one, except, if I will move to Lipoly packs then I have to get another charger suited for it. I also have the Duratrax Deluxe Pulse Charger for almost 5 years and it too works perfect for these type of batteries.

In my experience these are my charge rates,

Nicad 2100 & 2400 mah sport packs - 4.5 to 5 amps, 25 mv
NiMh 3000 & 3300 mah sport packs - 4.5 amps, 10 mv
NiMh 3000 mah race packs - 4.5 amp, 8 mv
Nimh 2100 mah 8 cell AA Airplane packs - 1.8 amps, 8 mv
Nimh 1100 mah 8 cell 2/3 A - 1 amp, 8 mv

For reference purposes only. Charge rates may vary according to battery age, capacity and condition.

thanks

Jim_Purcha

My Feedback: (8)

Thanks, I'll give these battery settings a try.

USABaja5B

Great review, I have one for almost 3 years now, and I love it. I mark all my batteries with the charge number, so you don't forget to change the settings.

For the tx batteries, you can get 4 or 8 pack holders from Radio Shack.

racer59

Hello to all.
I just purchased a used Piranha Digital peak charger w/o an instruction with the package of my Hawk Heli .30.
I am lost on how to charge my Transmitter and Receiver.
Can someone please help me?
Example--4.8vdc-500mAh, how do I charge this? I have been playing with the dial and still trying to figure out on how to
get in the proper functions.
Thanks,
racer59

critterhunter

Receiver or TX packs should be charged at a very low setting. I charge my 2500ma AA TX batteries at .2 or .3 amps. Your pack should probably be at .1 amps. If the packs are nimhs set the M/V at 3 to 5. If Nicads set them higher in the 10 to 14 m/v range. Turn OFF trickle. Set the capacity a bit higher than the pack, like at 600 or 700 MA in case the pack can hold more than it's rated for in capacity. Otherwise the charger will terminate as soon as it reaches the capacity setting regardless of whether the pack has peaked or not.

mountain_of_cheese

Critter, nice post. Lots of good info in there. I just received my Piranha charger today and was boggled by the inadequate instructions that came with it. This post has helped quite a bit, maybe someone can summarize it further into a spreadsheet or some kind of chart. Any takers?

critterhunter

Thanks. It really is a great charger for the money. Offers more features and functions in an LCD unit for it's price than others. I've gone lipo on my planes now but I still use this charger for my TX batteries and to top off friend's packs in the field. It gets a good extra amount of capacity into their packs that have only been charged on the stock hobbyzone/parkzone cigarette light chargers.

x030399

Ditto on your great explanations and info on the Piranha, Critter. I too used your post to "translate" the awful instruction manual. When you figure out how to use it, it's a great value for the money. I routinely get 100-200 mah over most battery's stated capacities into them, without them ever getting hot.

scott

critterhunter

Thanks again, but I was as lost as you guys until others helped me figure things out...like those who responded in this thread. I also do still use this charger for my monster 3300ma nimh packs that I fly in the Extreme. Even when friends charge their nimh packs on their chargers (Parkzone cigarette lighter charger or a Phrophet (?) ), they still like to re-peak them on this charger as it gets more into the pack (doesn't false terminate providing you set the threshold right...3 to 7 m/v for nimhs, much higher for nicads). Often the charge rate or too low of a m/v can false terminate the pack. For instance, if a I drain my 2500ma Engerizer AAs down dead (use them in my TX) and then slow charge them at .3 amps or so overnight, I may have to restart the charger two or three times within the first hour. This is because I keep the m/v setting at 3 m/v and the pack voltage will climb, drop, and stop while charging at such a low rate and at such a low m/v setting. However, I like keeping the m/v setting real low when I'm charging over night or not going to be watching the charge take place in person. This helps there to be less chance that the charger will overcharge things and cause a potential fire. If I had the m/v setting higher it might not see the packs voltage drop and terminate. Remember, nimhs and nicads will start dropping in voltage when they've peaked, but nimhs drop in voltage much less than nicads to indicate this. Hence the higher m/v settings for nicads over nimhs. M/V number X number of cells (automaticly computed by the charger) determines the amount of voltage the pack will need to drop before it triggers the charger to terminate.

mountain_of_cheese

I haven't tried charging batteries overnight yet, but I'd like to. Is it safe if the unit has stopped charging the batteries but is still on? I guess I could also hook it up to a lamp timer if it can handle the current draw.

I've also heard about people adding a fan to it, which I may try at some point, or maybe get a cheap solar panel and connect it to the fan to draw heat away from the transformer inside the piranha. Or maybe even an easier solution is find a slim aluminum heat sink from an old pentium cpu to add to it. Not sure it's worth doing.

critterhunter

Don't use a timer. If the charger looses power while a pack is still plugged into it it will sound an alarm and flash something like input power failure on the screen and keeping beeping (It uses your pack's power to feed it's self at this point so it can alert you). Also, if the charger terminates it's charge of the pack it is safe to leave the pack hitched up until you've got around to checking it. However, it is VERY important that you do NOT have trickle turned on for nimh packs. Nicads are OK to trickle after the charge is complete but it's not good (or safe) for nimhs. Make sure you have that set correctly. Great thing about this charger is it will remember your settings when unplugged, but it's a good idea to re-check that and other settings before each use.

mountain_of_cheese

I'm wondering if adding one of these thin film solar panels to the top or side of the charger will be enough juice to power a small fan to extract more air out of the back or top of the charger to maybe extend the life of it. Nothing would have to be bolted on so warranty coverage shouldn't be a problem. [link=http://cgi.ebay.com/Solar-Panel-Powersheet-paperthin-ultralightweight-60mw_W0QQitemZ6059037623QQcategoryZ41981QQcmdZView Item]solar panel[/link]

If battery heat were an issue, you might be able to rest one of these on a heatsink on the battery to pull heat away. I'll have to check if I can get by using 6v and such a low current on a small cpu fan.

critterhunter

Yea, the charger has the mount and vents for a small fan already in it, so hacking one to it wouldn't be hard at all. Still, I keep it and my packs cool in the field while charging by using a car fan. I have one that plugs into the cigarette lighter but I hitched aligator clips up to it. I always charge off my truck's battery in the field so I just clip the fan and charger to the battery under the hood. This fan (Walmart) is a big black one that has a strong holding clip on it to secure to your dash, so it can be put in a good position for the charger and battery under the hood. I try to use things that have other uses. I don't want AC in my truck (I work outside), so when on the road I simply use this fan to keep me cool.

cjtyped

My Feedback: (1)

Question:
NiCd 600maH, 4 cells. Recharged using Piranha.
Settings:
NiCd
600maH
0.6A
<I 6mV/C
Digital Readouts after charging:
T:041:54
6.624Vp

TrC 0377
6.217V

Can anyone tell me anything about this? I also have a CBA computerized battery analyzer; I intend to discharge this pack when I get off work.
Thank You in advance.

AJ DRAGON

Hi

If anyone still has one of these chargers and would like to add a cooling fan to it then the picture below will show where to hook the wires up at.



P.S. Sorry about bring this thread back to life.