Many of you may think that those of us who own a Hobbico Accu-Cycle should shelf it and buy a better charger/cycler. Many of us, like myself, buy this charger to replace our wall warts soon after getting into this hobby. I bought it before I discovered RCU, not knowing the brutally honest (but very valuable) opinions of REAL end users of this product.

Anyways, I've stuck with it and it has served me well for 3 years. Now my first battery packs may be nearing the end of their reliable lifetime. I wanted to make sure the Accu-Cycle is properly calibrated before I make the decision to chuck the old batteries.

When seaching RCU for instructions on how to calibrate it, I found that some people have never touched a multi-meter and don't know what it means to connect it in series to measure current. It really is very easy. Since it is such a common task for Accu-Cycle users, I thought I would take some pictures so that the "electrically challenged" users know what to expect.

Here goes...

1) Get a multi-meter and set it to measure DC current. I borrowed this Fluke multi-meter from work. I have to set the dial to measure DC current and I have to attach the red probe to the port that measures current. (Picture #1)

2) Start with a fully charged battery hooked up the Accu-Cycle. My Tx battery is connected here. Red lead to the red port. Black lead to the black port. (Picture #1)

3) Now connect the multi-meter in series. Do do this, disconnect the black lead and put the red probe into the black port instead. Now connect the black lead to the black probe. I just held them together. The multi-meter is now connected in series. Remember these connections, you are going to have to hold it like this when the Accu-Cycle is open and the ports are up-side-down and facing away from you. (Picture #2)

4) Set the discharge rate to 250 mA and start discharging the battery. The actual discharge rate will show up on the multi-meter. I was reading 257.2 mA. (Picture #2)


5) Open up the Accu-Cycle. The picture shows where the Tx and Rx potentiometers are. (Picture #3)


6) Adjust the Tx pot so that you bring the current back down to 250 mA. You are going to have to hold the multi-meter in series and start the discharge cycle before you do this. (Picture #4)

7) Do exactly the same thing to calibrate the Rx discharge rate. I'm too lazy to take the battery out of the fuse, so I brought the whole fuse over. Remove the switch and connect the battery directly to the charger. Change the "RX CELL SELECTOR" to 1 cell (don't know why), hold the multi-meter in series again, then start discharging. (Picture #1)

8) Adjust the Rx pot until you get 250 mA. (Picture #2)

9) That's it! Screw the top back on. Notice I used 18 mAh and 20 mAh to adjust the Rx and Tx discharge rates, respectively. Top off your batteries before you start cycling again. This time you'll be more confident about the mAh readings at the end of the discharge. (Picture #3)

I hope this helps...

Juice

Thanks abunch Juice,
Anybody that owns one of these should do this.
I always wondered why my RX packs looked like they needed replaced even when new.
TX waxnt too bad at 257, RX was at 277!!!!!!!!!
Set them both to 250 and now they look like the new packs they should be.
How about the accucycle plus, is it the same?
Thanks

I don't know for if it is the same for the Accu-Cycle Plus. An Accu-Cycle Plus owner will have to comment on that.

Juice, good job on the instructions ! The reason why you need to select a lower cell count is to "cheat" the accucycle so that it does not go into charge mode (there is a potential drop across the DMM when its connected in series). My accucycle has served me very well over the years and I haven't had the need for another charger. Yeah, it's a little extra work to calibrate it, but hey, I think you learn quite a few interesting stuff along the way right ?

Juice, very good post it should be stuck to the top of this forum. I’ve tried to explain this here a couple times with much fewer words.

I have done this to my Accu-Cycle and a buddies Accu-Cycle Plus. The Plus works the very same way. However when I tuned his Plus there wasn’t enough adjustment on one of the pots to bring it to 250.

7) Do exactly the same thing to calibrate the Rx discharge rate. I'm too lazy to take the battery out of the fuse, so I brought the whole fuse over. Remove the switch and connect the battery directly to the charger. Change the "RX CELL SELECTOR" to 1 cell (don't know why), hold the multi-meter in series again, then start discharging. (Picture #1)

Does anyone know why you must select 1 cell???

9) That's it! Screw the top back on. Notice I used 18 mAh and 20 mAh to adjust the Rx and Tx discharge rates, respectively. Top off your batteries before you start cycling again. This time you'll be more confident about the mAh readings at the end of the discharge. (Picture #3)

I notice the 18 & 20 mah in the pic but wouldnt this be time or compacity of the battery once discharged depending on what you have the selector switch on. Could you explane more of what you mean by " I used 18 & 20 to adjust the discharge rates". I'm lost there.

See [link=http://www.rcuniverse.com/forum/fb.asp?m=1527003]Post #6[/link] of this thread for the answer.

The 18 and 20 mAh really has no relevance to the procedure. The Accu-Cycle is in discharge mode when you are doing the calibration. 18 and 20 mAh is how much the batteries partially discharged while I did the calibration, expressed in mAh. Assuming a constant discharge rate of 250 mA you can also express this in time:

18 mAh / 250 mA = 0.072 hours = 4 minutes 19 seconds to calibrate RX
20 mAh / 250 mA = 0.08 hours = 4 minutes 48 seconds to calibrate the TX

Again, this has no relevance to the procedure. Everyone will take a different amount of time to calibrate their charger.

Hope this helps,
Juice

Thanks Juice,

I completly understand & should have to start with. BRAIN FART!!

Thanks. I was about to trash two battery packs. I check my accu-cycles; one was at 272.4 and the other was at 263.2. I calibrated to 250 and the packs went from 76% to 85% capacity. I will fly them now, and as always keep a track on their capacity.

Juice thanks for the great tip! I calibrated mine works just like you explaned. THANKS

Lonnie

I have a plus. I just checked mine and its bang on

I have just puchased my first futaba 6 volt battery,but it came with no charger,I have the accu charger,do I simply just set the cell setting to 5,and thats it,?????????????

Juice.
Great tip. I know my Accu-Charger is not up to "snuff".
I have a RadioShack multi meter (22-810) which I can set to DC--2V, 20V, 200V, and 500V.
Which should I set it at?
Thanx a bunch...croz

2rolls your meter wont be on any voltage setting but rather the DCA setting like the one in the pic I've posted. If yours is like this one unfortunatly its max range is 200 ma & you need a min. of 250 + since this is the lowest setting if I'm not mistaken on the discharge of the Accucycle. If you try to use it there is a little fuse inside that will blow more than likely. It may handle the 250 + or - mills but if it dont all you will be out is a 50 cent fuse.

You will however be able to hook it up & check the charge rates to see if there acurate since the max there is 125ma

That should be it but I would besure to charge & discharge the pack a couple of times to see whats in there after a charge.

RSROGERS, thanx for the heads up.
Mine is exactly like the one you pictured.
I'll locate another meter...thanx again...croz

Rajul, A few months ago you had talked me through this process in calibrating my Accu Cycle which is now working perfectly.

My question is, how do we check on the charging side of the Accu Cycle to ensure that is working correctly, or is that a given once the discharge values are correct.

Hi karolh, sorry for my belated reply. I missed your post somehow.

To answer your question, you can check for the charging current using your DVM connected in the same way between the charge port and battery pack, as when you were measuring the discharge current. I have also found it to be easier to use a H9 in-line current meter to verify the actual charging rate. One thing you will find out is that after some time, the internal contacts of the selector switch charge current will get dirty or oxidized, and the resulting higher resistance will cause a drop in the charge current. Slide it back and forth several times to clean the contacts, and the charge current will go up. The in-line meter is helpful in this respect as a quick way to verify the actual charge current. It's easy to use - just plug it between the pack and the charge cord.

Hi rajul, thanks for your reply. Due to the time difference between us of approx. 4 hrs. I thought that your response was quite timely.

hello

can you explain to me what you meant when you said
you used

l8 mah and 20 mah to adjust the rx and tx discharge rates


thank you

ralph

I asked the same ?? heres the answer from a previous post:

The 18 and 20 mAh really has no relevance to the procedure. The Accu-Cycle is in discharge mode when you are doing the calibration. 18 and 20 mAh is how much the batteries partially discharged while I did the calibration, expressed in mAh. Assuming a constant discharge rate of 250 mA you can also express this in time:

18 mAh / 250 mA = 0.072 hours = 4 minutes 19 seconds to calibrate RX
20 mAh / 250 mA = 0.08 hours = 4 minutes 48 seconds to calibrate the TX

Again, this has no relevance to the procedure. Everyone will take a different amount of time to calibrate their charger.

Hope this helps,
Juice

After reading through all of this, Juice, I wish to also add my thanks. You probably have saved many of us two things: 1. replacing batteries that really were not bad, 2. saving a potential crash!

Thanks again.

Great to have this never read anything about that and have been using an accu-cycle. Added a post to put it in my list so I can get back to it easy.