I am curious as to what might be the solution to a problem I am having. I am running a std servo for throttle, three 5945, and an 8611 for flight controls.

The problem is the 2700/5cell nimh that I am using is a bear to charge as the Trition and Activator chargers that I have will trip out after anywhere from about 275mah to about 650mah at a time.

I got back with the vender that I got them from and checked if it is okay to go with a constant charge 500mah 9v wall wart. They said that will be fine just make sure that I monitor the temp and time.

I figure the guys with the really big birds that are using multiple packs and heavier draws than this, which begs the question how do you charge them when they are Nimh?????

what settings are you using on your triton charger?

Sounds like you may have a problem with your chargers. Or the wire gauge you are using for the charge wire is to small, generating excessive resistance. Just for the heck of it, try using 12-14 gauge wire for the charging leads from the charger. The Triton should be able to handle 1 amp plus charge loads. If you still have them, check the directions to see if there may be any issues that may be creating the problem.

Also ....... when you charge, how many flights have you had on those batteries before you recharge. Your figures would indicate something like 1 to 3 flights for the charge rate the chargers are putting in the batteries. For your servo load, 250Mah to 350 Mah of battery discharge per flight would be pretty normal. Remember, unless you discharge your batteries completely between charges, you only have to put back into the battery what you took out plus a little additional for overhead. I find it hard to believe that both chargers are bad and Silversurfer's advice regarding charge lead wire gauge is a good one. NIMH batteries are no harder to charge than NICD ones if the charger is designed for them.

Roger S.

I had similar problems with my triton. It would always seem to stop charging pre-maturely on certain packs. You could do what i did and sell it on ebay and buy the hobbico accu cycle elite. That way you can charge two packs at once.

It's my guess that it's a combination of a charger with too-strict rules and batteries with too-high internal resistance.

Your approach of using a wall wart is good, but they are 50ma, not 500ma, and charging yor 2700mah pack from zero would take at least 4 days.

I suggest you look for a different pack with low internal resistance, the kind designed for electric motors. I'll bet that the plane will fly better also, I doubt you are getting full power to the servos as it is now.

TF

I have only had one flight on the pack and that was to see about how much would be used per flight.

I did a first charge as per Dave Thacker at Radical RC and then flew the plane after some radio set up time and used about 500mah

I then discharged the pack and first tried tried 2700 with the Triton and it kicked at about 625mah and the second time tried at 500 and it kicked again at about 275. I then tried the Activator and it kicked at around 325.

I checked back with Radical RC about using a WallWart that I had at the house from some old something that no longer works, but the transformer still does. It is a 9v 500mah wart that they said will work fine and it will then take about 6hrs. I will have to start doing a routine of Friday & Sat nites that I dis on the Triton and charge on the wart. Gone are the days of only charging at the field.

You have to put an initial formatting charge on your Nimh batteries. Then every other charge, do a complete discharge/charge cycle to keep the batteries in top condition. I had the same problem as you, but with a new 2200mah 8 cell Nimh pack for my transmitter. There's nothing worse that getting the dreaded low-voltage warning and know that you have about 30 seconds to get the plane on the ground before your transmitter shuts off. I've had the receiver packs get wimpy after 6 months of continuous charging on a Hobbico quick charger.

As with other support equipment, I have found that as the planes get bigger, more expensive, with more reliance on the batteries, upgrading to a good charger and voltmeter is well worth the money.

Go to http://www.hangtimes.com/nobsbatteries.html for great batteries and information. I now use a Miniron charger (http://www.rcbatteryclinic.com/Minron.pdf) with a 25A power supply to keep all my battery packs in good condition. Yes, it's a $400 investment, but it's good insurance when flying my $2000 W-H.

Also, use a good voltmeter like the Ace or H9 that not only gives you the voltage output, but puts an adjustable load on the batteries that tells the true condition of the pack. Also, don't go cheap on the RX switches. Power issues are sometimes a switch issue.

I flew electrics with Nicad, Nimh and Lipoly batteries for a couple of years before getting into glow and gas planes. I got by with a Hobbico quick charger and the 200mah wall chargers for a long time, but the batteries only lasted one season. I've tried the Ace chargers, but they just charge for a set rating at a set period of time. The Miniron actually detects the cell count and adjusts charge rate and time automatically and even allows you to manually modify the charge programs to meet your specific needs.

Sometimes there is some truth to the old saying,"You get what you pay for." On the other hand, it's all relative to the way you view the hobby.

Good Luck,

Jim in Dallas

I will see tomorrow how it worked.

I did a discharge and then used a 9v transformer at 500mah output for 5.5hrs. the pack got pretty warm for about the last hour but not to hot I dont think

Terror,
I just finished a WH 28% Edge. It has two 2700 MAh Sanyo packs wired in parallel. They were formed with a Litco Alpha 4 charger and both are showing in excess of 2900Ma when cycled at a 500 Ma discharge current. The Alpha-4 seems to work well with the NiMH batteries.

However, they are high-internal-impedance cells, maybe too hight to be used as a single pack in a 28% machine. Sanyo makes a 1950 cell with MUCH lower internal impedance that would probably be more appropriate when used in a single-pack application. Using two packs in parallel reduces the effective internal impedance of each of the packs by one half. I wanted the safety of the redundancy of a two-pack system and the 2700s weigh the same as the 1950s.

BTW, I would NOT charge that 2700 pack at 500 Ma. Higher internal resistance requires lower charge rates. I think 500Ma charge rates will greatly shorten the life, and perhaps reliability, of the 2700. In short, I agree with Tom... get a pack more appropriate for the intended use.

In the menu for the Triton make sure the peak detection setting is at least 6mv and that your safety timer etc are not to low.
I just got one from someone that said it was useless and the cause was he had it at 3mv settings which means it will always false peak.
Nimh can sometimes take 3 cycles to form up.
The Triton is as good as any out there, I have gone out and paid 350 for one that performs no better.
Also if yours does not have a yellow or green sticker on it it may need an upgrade ( free )
I have also found that it performs better if you set up the battery in memory and adjust your parameters there. Left on auto it defaults to very safe settings.
You can do a forming charge with it by turning up the safety timere to either off or at least 10hrs, turn the peak sensitivity to its highest ( Dont forget to put it back!) and the capacity to much higher than the battery and lastly set a C setting of a tenth of capacity.

Silversufer is spot on about the leads, get good ones ( Hobbicos have a tendancy to break internally ).