RC India

Hello,

Before inserting the battery on my plane, i checked the voltage with lipo voltage checker and it is showing as fully charged. After putting the battery, along with voltage checker/buzzer, on the model, and i was testing the controls throttle for few seconds and the low voltage alarm started shouting. I see there is a huge sudden voltage drop of the battery. Then i stoped throttle and then i see the voltage checker is showing again fully charged.

Anybody else facing the same problem. Is there any way to resolve this problem. I have 4 batteries ( 3S, 2200mah, 20c ).
All batteries are behaving in the same way. Batteries are good in shape, not even single bit of puffing.

You can check for a short circuit or some jammed  motor in circuit . Which battery you are using.and how much cycles on battery?

looks like a low voltage alarm problem... have you tried with some other voltage checker?

How many cycles (charge/discharge) have these batteries done? Chances are high they have croosed their useful life

Which brand are they? Turnigy have been known to pack up within 50 cycles

I have just changed the battery (new one), and used the same set of motor, ESC, Receiver, Transmitter and it worked fine. No Buzzer and no sudden voltage drop with that battery. it went fine.

All my 4 batteries are wolf pack batteries and i have been using them from the last 1 year. But all batteries suddenly started giving problem (On the same day, just charged all the batteries on the same day). I thought it was the problem with the charger, which corrupted all the batteries. i am using wolf pack B3 charger.

Thanks
Kumar.

Do you have a watt meter (showing V, A, W and individual cell voltage?)

No Sir,

I do not have a watt meter.

But the lipo voltage checker is showing each individual cell voltage. When the throttle is on i see a huge voltage drop down in individual cell also. Below are the results the voltage checker is showing

All 12.6 > Cell1 4.2 > Cell2 4.2 > Cell3 4.2
All 11.7 > Cell1 3.9 > Cell2 3.9 > Cell3 3.9
All 11.4 > Cell1 3.8 > Cell2 3.8 > Cell3 3.8
All 11.1 > Cell1 3.7 > Cell2 3.7 > Cell3 3.7
All 10.8 > Cell1 3.6 > Cell2 3.6 > Cell3 3.6

and the buzzer starts shouting......All this is happening within a minute. Once i down the throttle (complete down, zero throttle), again the values are going up.

Thanks
Kumar

The watt meter can show the voltage as you gradually increase the throttle. Can your checker do that? If so, try please

It can tell if the cells are gone ie if on load the voltage just drops. That means the battery is finished. I think that is probably the problem, as you say on a new battery there is no problem. You say they are one year old and used regularly? In that case their useful life could be finished.

@kumardasai,
Large voltage drop under load means one of two things:
1. Load is too much. Please mention details of motor and prop.
2. Internal resistance of battery too high, ie battery spoilt.

Your problem seems to be #1 above.
Post motor/prop details please.


Edit: this is in addition to what Rai saheb said in the previous post.

Iyer sir, he has mentioned

a) he has been using these batteries for a year
b) With a new battery all works fine

@K K Iyer :- The same battery with same motor and ESC i used for one year and i really enjoyed that flight time. All of this happend suddenly. The Motor is 3150 and prop is 11X6 size with 30 amps ESC with 11.1v 2200 mah and 20c battery.

@sanjayrai55 :- Yes sir, the voltage checker also works in same way, it keeps showing the values for all 3 cells and for individual cell as well, even the throttle on.
If any cell is dead, then it would show the cell count is 2. But the voltage checker is showing the cell count 3.


The batteries are looking like new batteries as there is no puffing at all, no damages at all. I really dont want to throw them away. Not just 1 or 2, They are 4 batteries.

@sanjayrai55,
Didn't notice that. Careless.

@kumardasai
In that case batteries gone as Rai saheb said.

But i'm still curious about the load.
Please give more details of the motor.
3150 is not enough for a search.

If the battery has crossed it's useful life, a cell will not necessarily be dead. It just cannot take load.

Puffing happens because of overheating, and is not the sole criteria of a battery's condition

@K K Iyer :- If any fault in the motor or esc, it should behave the same with new battery. But if i put a new battery ( same configuration 11.1v 2200mah and 20c) it is working fine. Motor Details are : Out runner brushless AT3511 KV750.

But I am really surprised all the batteries spoiled on the same day.  :headscratch: I doubt about the charger. I dont want to take risk, by charging my new battery with this charger. Before that day, all the batteries are working fine and no sudden voltage drop at all. They all are giving excellent flight time.

@kumardasai,
Still not enough detail to identify motor!
Presume its from toprchobby.com
If so, its max draw is 40 amps.
So you've probably been using 18-20c.
These lipos claiming 20c can usually only support 10c.
I've been using Zippy compact 3s 1000mah for over a year as i rarely draw 10-15c.
I think your 1 yr old lipos are dying because of higher draw than they are capable of.

You must be drawing over the load of the battery, could either be your esc or the motor (or anything else between them) that is draining the load. I suspect the ESC as the fet's could have failed partially due from overheating over the period of time of its use.

Try changing a newer & slighter larger ESC and it should solve the issue, if not else the motor is culprit., Nothing else that crosses my mind at the moment.

One year, regular use, normal battery life over - probable

4 batteries failing simultaneously - improbable!

Check your charger too. But these 4 batteries are gone I think

Yes Sir, All 4 batteries gone on the same day. This is the reason i doubt on charger.