NAZA rapid flashing red + LOW-VOL[4] error in assistant with a fully loaded LIPO !

kloner

kloner

Aerial DP
your batteries are toast, you smoked em, you need more

it's not all that weird, you have to know what your doing with them or they'll go away in one flight

8 volts in a couple minutes tells me you've lost one cell. a 2 cell pack starts at 8.4 volt

I wrote it a zillion times in this thread, if your not seeing exactly 12.6 or within .05v of that after charging, your pack is done, smoked, gone away , you don't have batteries anymore
 

S

skipper1

Member
Kloner, are you saying that a 11.1v battery should be charged to 12.6v? Isn't that overcharging and asking for an explosion?
I have brand new Spyder batteries (3S 2.2a 25c) that have flown once. Of the 4, I checked 3 after the red light began flashing and the voltage read 10.98, 10.95 and 11.34v. Wouldn't 50% of an 11.1v battery be around 5.5v? If so, I'm not even getting 50% use of my new batteries.
I checked my voltage monitor in the assistand and first warning; no load 11.2v, loss .50-Loaded 10.7.
Second warning; no load 11v, loss .50-loaded 10.5v. This is all very new to me but just looking, those number don't look correct at all to me. And I don't see how my new batteries could possibly be toast. Let me stick my tongue to the terminals. Ouch!
I charged Sunday evening and I just now checked the voltage on all 4; #1 11.08v, #2 11.03v, #3 11.18, #4 11.12 v. That does not look like toast to me. Please understand, I am not trying to start an argument, just posting what I'm seeing. I think something is not right with this.
I would like to see some of the more experienced fliers, like you Kloner, give their opinion.
 

kloner

kloner

Aerial DP
absoluteley they should be charged to 12.6 or 4.2 volts a cell. Any other action especially taking it bellow 11.1 smokes the pack, instantly within one flight. not a question in my mind.

if you charge a pack and it's not within .02-.04 volts of each other it's beyond smoked, it's trash

You killed your packs one by one by over discharging them the first flight

if you don't believe me search the web for rc lipo instructions or read this
http://www.rcgroups.com/forums/showthread.php?t=209187

Can't wait to hear what progressive tells ya when you start telling them these numbers and wanting new ones
 

kloner

kloner

Aerial DP
these are my packs, range anywhere from 3 days to 1.5 years old, all sitting there at 4.2 volts a cell ready to fly, none of them have any damage whatsoever.

022%20%281024x598%29_595.jpg


Can prove it by measuring the internal resistance, in fact just did, that's the numbers all over them and none have over single digits per cell.
 

M

mailman35

Member
a cell tester/checker is be best thing to ever buy, as you know instantly whats up with the pack u are about to use.
 

Coomkeen

Coomkeen

Member
I'm having exactly the same problem.
3 cell 2200 20C, three of them exhibiting the same red flashing led a few seconds after take off.
Check with multimeter shows over 12 volts, but that's no load conditions.

I had previously (a few days before) flown for 5 minutes or so with one of the batteries with no problems.

Checked all the Assistant settings and all looked fine.

So today I put a 4 cell 30C pack on, set the Assistant to the right voltage, and away it went with no problem.

The 4 cell pack was an unused one, although I had had it or 6 months or so from new.

Looks to me like the internal resistance of the packs has gone up too high.
They are ok in single motor fixed wing even now, where the current draw is way less.

Ron

EI8GMB - G6IWK
www.bandonmodelflyingclub.com
 



S

skipper1

Member
Kloner,
I hate you and I hate humble pie. I have a feeling you may have been down the road that some of us on the forum are experiencing. I have learned a lot the last few days from you and you point us in the right direction.
You have been correct in everything you have said. If you're using a 3s battery, charge that thing to 12.6v.
I talked to David at Progressive and since these batteries were brand new and wasn't tearing up the sky, I may get lucky. Time will tell.
BTW Kloner, I really don't hate you.
 


kloner

kloner

Aerial DP
you want to try and get a battery and just use em right so they last. IF you do everything right you'll get 200-300 flights till this kinda stuff happens or 2 years.

The other lipo killer is heat. never leave your batteries in your car closed up, always try keeping them 70 degrees if you can. Always store them discharged to 3.7 to 3.8 volts a cell. your charger has a mode made for it, on my stuff that's just what they hit at the end of a flight

yea, humble pie sucks

if you switch to 4s, it is going to also increase your maximum draw like full throttle without changing props. You want 8-9" props on 4s with 900-1000kv motors
 

kloner

kloner

Aerial DP
Ron, them numbers look like a tired old pack that's been taken care of, but done. they don't hold as much as new, they start not holding balance, and there not holding as much mah
 


S

skipper1

Member
Kloner,
Can you point me in the right direction on how to get 12.6v into my 3S 11.1V 25C batteries. I have 500 watt power amp and Powerlab 6. The best I can do is charge till it's empty, 11.08V. (this humble pie is starting to taste pretty good)
On my charger I chose LiPo generic, Accurate charge. Set at 4.4A, Balance 1Cy, no parallel, then it asks to set discharge rate. I think the discharge rate should be 55A but the charger doesn't give me that choice. I guess, in order to get 12.6V, the numbers should be higher, but how much higher?
 

kloner

kloner

Aerial DP
i just tried reading your manual but for crying outloud is there a ton of crap in there. 88 pages

if you have a charger specific question, get ahold of progressive and have them walk you through specifics. on mine (306b) i just set it to lipo, balance charge, i plug in 6 to the balance board and hit start till it beeps. it automaticaly stops at 4.2 volts a cell. there is no other finished charging program i'm aware of that does anything different. Usually if your results vary one of the cells isn't fully charged, usually from damage. You shouldn't have to discharge anything
 

S

skipper1

Member
kloner said:
i just tried reading your manual but for crying outloud is there a ton of crap in there. 88 pages

if you have a charger specific question, get ahold of progressive and have them walk you through specifics. on mine (306b) i just set it to lipo, balance charge, i plug in 6 to the balance board and hit start till it beeps. it automaticaly stops at 4.2 volts a cell. there is no other finished charging program i'm aware of that does anything different. Usually if your results vary one of the cells isn't fully charged, usually from damage. You shouldn't have to discharge anything
Click to expand...

Thanks, Kloner. Exactly. I get car sick everytime I try to read that thing.
 

K

KeithM

Member
You have low voltage. The Naza built in voltmeter detects only 11.03 volts. A full charged 3S battery is 12.6 volts. You need to check your batteries with a quality digital voltmeter. It appears your battery is either defective or not fully charged. When the motors start, the load on the battery increases which further drops the voltage, hence, triggering the alarm.
 

Coomkeen

Coomkeen

Member
I must make an internal resistance checker somehow.
Maybe the bench power supply set up as a 1 amp current sink and the multimeter...?

Hmmmm.

But... Maybe....

Anyone know of a reliable, cheap internal resistance checker?


Ron

EI8GMB - G6IWK
www.bandonmodelflyingclub.com
 

S

skipper1

Member
Thanks, Keith. It took a while but have that much figured out. Being a noob, you get an 11.1v battery, plug in your CellLog 8 and it shows a little more than 11.1v, you figure you're good to go. Not so....live and learn. As you stated, it needs to be 12.6v.
Problem, how do I set my charger up to get 12.6v into that battery? PowerLab 6 is supposed to be idiot proof. Guess what, it ain't. Reading the manual, I may as well be trying to read Chinese. Good car sickness reading.
Who would have thought that yo need to be an electrical engineer just to charge a stupid battery.
Someone knows the answer to my problem and I'm just hoping they happen along with a little help.
 


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