Low voltage...

[Lee Taylor]

Alright, the last time I had this bad boy out at the field, I was reading 7.2 or so on a 1A load test. After this check, I only flew one flight. Anyway, I made sure (as always) that the switch was off before I left the field. NOW, 2 weeks or so later, I go out to the field and get ready to do my pre-flight, and I get no power to the Rx side of my system (as in, I DID have to turn the switch on...so it WASN'T left on). No gyro light (401) or anything. So I finally get a chance to check the voltage and I'm sitting at around 1.1V. I put it on the charger at the field for about 2 hours to see what would happen (keeping a very close eye of course), and checked it again after the 2 hours or so to see if anything came back to life. I got a reading of around 6V with no load. I've got the battery on charge as we speak, and will do another E check every couple hours, until the pack makes it to 6 or 7 hours. My first question is, if I get the pack back up to around 7.5V with a 1A load, will it be okay to use? And two, (assuming the previous happens), is there a possibility of damage only done to a Li-Ion (Duralite in this case) if the voltage drops below the recommended threshhold under a load? I don't know too much about Duralites at this point, but would like to add it to what I'd like to think is a somewhat vast knowledge of electronics. Any inputs would be greatly appreciated. BTW, this is a 4000mAh pack. THANKS!!!

[Kinger]

Lee - Call Duralite and have them check your regulator. Buddy of mine had all kinds of problems with his batts losing voltage while they were just sitting on the bench (VERY unusual) and he traced it back to a bad regulator.

[Lee Taylor]

See I thought that was the culprit too, so I may have to do that. A second opinion with agreement helps out. I think I told Robert that this morning when I discovered the problem...(first person I usually call with any problem...lol). Because that's the only other thing in the circuit besides the wire to the regulator, and Rx...and switch. But I did resistance checks on the switch and it checks out. I think I know a way to check the regulator though, but if it doesn't work out, I'll send it off and have Duralite check it out. Thanks for the input.

[Bonsai]

Hey Lee the best thing to do is to call duralite and talk to them and tell them everything that you have done..they are really good people and will steer you in the right direction..You will more than likely send your system in for a complete check up... I have one pack now thats reading 6 volts and I think that is my problem too. :arggg:
Dean

[Lee Taylor]

Well, I went out and checked the E coming out of the regulator, just to see if it's reading what its rated at...and I don't think something is quite right. I'm pretty sure it's a 5.1V regulator, but right now it's regulating the system @ around 5.6V(5.631V). Which really isn't going to hurt anything, just so long as it doesn't go any further...(if in fact it's a 5.1V reg.)...but if I remember right, Duralite has 5.1V, 5.6V, and 6.1V regulators. So I may indeed have the 5.6V and never knew it. I didn't buy this system new. BTW...

Jeff, Is this the 5.6V regulator? Or do I have a regulator heading toward the way side? LOL...

I think it may very well be the 5.6V reg., because it is so close to the 5.6V rating. ANYWAY, the last check I took on the pack was about 20 minutes ago, and it's gettin' there...right now it's around 7.7V without the load (because I don't have the tester yet), so it's getting up there. Another couple of hours and I think it may indeed get back up to around 8.1 to 8.3 volts. I'll make an update here in a couple hours, and will post the results of the load test tomorrow when I get back from the field. :mrgreen:

[Lee Taylor]

Just a quick update...the pack now reads 8.28V with no load. When i get to the field a little later I'll throw it on a 1A load, and see what i get and post it up on here. And also, I was off a little last night when i was remembering what E the regulator was putting out...I thought it was 5.631V, but it was actually 5.831 volts. Checked it again this morning. So it looks like the SCR (what they're using as a voltage regulator), is going. Anyway, I'll keep the info updated...Thanks.

[angelob]

Are you checking the regulator under load? If not this will account for the higher reading. I saw the same thing so I hooked everything up and ran an extension from an unused channel on my receiver to my voltmeter - when I turned on the receiver, I got 5.1v.

Angelo

[Lee Taylor]

Yeah, I talked to Clint and realized what I did wrong. It is a 5.6V regulator.

UPDATE: I got to the field and threw the load tester on the battery..1A...and it sat right at 7.8V or so. I check the pack after every flight almost, and even by the end of the last flight, I was still sitting at 7.2V. So, I'm going to continue to keep a close eye on the pack at see what it does...but will probably send it to Duralite to let them do an analysis on it. I do think one of the cells may be either dead or working on it. When i pulled the pack off of the charger, the light was still lit...dimmer, but still lit. So I'll check the voltage again late tonight and see what it's reading, to see if indeed the potential dead cell, is pulling down the rest of the pack. But it looks good so far, and didn't hardly lose any charge after 5 or 6 flights...THAT ARE GETTING HARDER, I MIGHT ADD...LOL...SLOWLY, but surely. :mrgreen: ...

[DavidH]

7.8 volts with a 1 amp load on a fully charged pack is OK. There is nothing wrong with that pack if it shows the above.
The battery is in the biggest band of its capacity when it is in the 7.6 to 7.2 volt range with a 1 amp load.
If is normal sometimes for the light to remain dimly lit on the charger.


David

[Lee Taylor]

Just thought I'd put this out, for the record, that the reason the pack made it down to the 1.1V, is completely my fault. I know better, but must not have been thinking straight when I put this pack when in the EVO when I rebuilt it. The way it's supposed to be setup is; battery, switch, THEN regulator, and that plugs up to the Rx. I know better, but like I said, must have not been thinking straight. When I did this, even though minute, the regulator pulled a very small load from the pack, and after the two weeks that it sat from me being gone, it took it down like it did. I definitely think I am one of the lucky ones as well, but I still think I'm going to have the pack checked out for safety sake. Like I said in my last post, I think I may have lost one of the cells, because the LED on the charger doesn't go completely out, even after 7 hours.

I am very happy with my Duralites. They definitely perform better than any other battery I've ever flown. I'll definitely never go back to anything else, that's for sure. :mrgreen: Hope my inputs on here have maybe helped some of you who may also be experiencing self-induced problems(i.e., correct setup)...LMAO...It happens to the best of us sometimes.

[Clintstone]

Glad you found the Problem Lee,,,,,,,,,,,,,,just got in from Mac's.........Later Man.

[Lee Taylor]

Thanks for the help too Clint. Hope you guys had a good time down there. I know we did today...hopfully the rain won't last long tomorrow, and we'll still be able to head out. MUST BURN MORE NITRO!! :twisted:

[Lee Taylor]

When I pulled the pack off of the charger this morning, the charge light was almost completely out, which from what I understand is normal, and the pack read 8.41V without a load. So I think nothing actually happened to it. Just thought I'd put that up here...Thanks to all who helped me out. :mrgreen: