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-   -   new batteries not working ... PLEASE HELP!!! (https://www.rcuniverse.com/forum/batteries-chargers-84/10671343-new-batteries-not-working-please-help.html)

TheKennyKiller 08-15-2011 03:52 AM

new batteries not working ... PLEASE HELP!!!
 
1 Attachment(s)
I need some help ... so I have 2 new venom 1600mAh nimh batteries and I can't get them to work I did a charge discharge charge on both of them at 1.6 amps and when I plug either of them into my mini e-revo the receiver light blinks red once very quickly and then nothing ... I am not using a series or parallel connector just plugging them in one at a time ... if I plug in the stock traxxas battery that has had the same charge discharge charge but at 1.2 amps the truck works fine and I have full power and steering ... can anyone help me understand what is happening ? ... the charger I am using is a racers edge surecharge 2010

TheKennyKiller 08-15-2011 07:44 AM

RE: new batteries not working ... PLEASE HELP!!!
 
I just did another discharge charge on one of them and same problem. I didn't mention before that the esc light and the receiver both blink red once very quickly as I press the button on the esc ... so I am thinking I might have 2 dud batteries which is strange I thought venom was a decent brand and I got them from tower but if that is the case hopefully they will send me a couple of new batteries ... if anyone has any other ideas on what might be the cause I would be glad to hear it ... I have heard that sometimes a cell can die but for this to happen to two brand new batteries seems a bit odd

Rodney 08-15-2011 09:31 AM

RE: new batteries not working ... PLEASE HELP!!!
 
I doubt that you got two bad batteries. Do you have a volt meter ? If so, check the voltage on the output pins of the batteries. Better yet, if you have an ammeter or a watt meter, put it in series with the battery when you hook it up with the load and see what it measures. Chances are you have a connection problem somewhere, could be in either connecting those batteries to you charger or to your load. If you have a friend or mentor to help, have them take a look at your setup, sounds like you are over looking something that may be easy to fix.

TheKennyKiller 08-15-2011 09:49 AM

RE: new batteries not working ... PLEASE HELP!!!
 
thanks I have a friend with a volt meter so I'll ask him to come over tomorrow, also I just did another discharge and I took note of how many milliamps were taken and it was 1243mah from an apparently fully charged 1600mah battery so not sure if that sheds any light on the situation, I'll do a charge and see how many milliamps it takes ... as you can probably tell I don't know a lot about charging but I have been doing my research and reading my manuals so I am trying to get my head around it (mainly so I don't burn my house down) ... thank you for your help

TheKennyKiller 08-16-2011 12:12 AM

RE: new batteries not working ... PLEASE HELP!!!
 
just checked the batteries on a multi meter and they both are reading about 8.2 volts which is strange because I thought I was going for 7.2 volts anyway both batteries read about 8.2 volts but still neither of them work in the truck while the stock traxxas battery is still going good and it also had the same 8.2 volts reading ... venom said they will send me some new batteries free of charge and they were very quick to do so, so either they have awesome customer service or they know something I don't ie maybe a bad batch of batteries ? who knows but all I want to do is plug in my batteries and run my truck, I hate it when simple things become complicated

jester_s1 08-16-2011 05:30 AM

RE: new batteries not working ... PLEASE HELP!!!
 
You could have a bad cell that will put out full voltage with no load but drop down to nearly 0 when it has a load on it. You still should have gotten some receiver function even with 1 bad cell though. Are you sure the connectors on your new batteries are good and compatible with the ones on your car?

TheKennyKiller 08-16-2011 06:27 AM

RE: new batteries not working ... PLEASE HELP!!!
 
yep all the connectors are the traxxas plug and if you have never seen them believe me they are fool proof ... today I charged my 1200mAh that came with the merv and it took on just over 1200mAh and when I charged both of the 1600mAh batteries in question they both only took on just under 1200mAh ... my understanding is that the 1600mAh batteries should take on around 1600mAh and if the milliamps are divided up between the cells equally and my math is right that must mean I'm down two cells per battery ... am I right ?
if I am than I guess it is really bad luck considering these are the first batteries I have bought for my first ever electric r/c but I'm glad venom are being good about it

TheKennyKiller 08-21-2011 05:46 PM

RE: new batteries not working ... PLEASE HELP!!!
 
1 Attachment(s)
I was going to start another thread but I kinda have the same problem. I just got some Lipos (3s 11.1v) and when I charge one of them and check each individual cell only 3 of them are taking charge. This is my first lipo and it's on it's first charge but I am pretty sure that all six cells are meant to be charging at the same rate. Do I have 3 dead cells ? if I do I will never buy venom again

TheKennyKiller 08-21-2011 05:53 PM

RE: new batteries not working ... PLEASE HELP!!!
 
and the first one just finished charging (seemed to charge way to quickly) and it won't work in the truck... same problem as with my nimh. plug it in turn it on and the light on the esc and receiver both blink red once really fast ... fml

TheKennyKiller 08-21-2011 08:45 PM

RE: new batteries not working ... PLEASE HELP!!!
 
emailed traxxas so hopefully they will know what is up

BigTb17 08-22-2011 03:15 AM

RE: new batteries not working ... PLEASE HELP!!!
 


ORIGINAL: TheKennyKiller

I was going to start another thread but I kinda have the same problem. I just got some Lipos (3s 11.1v) and when I charge one of them and check each individual cell only 3 of them are taking charge. This is my first lipo and it's on it's first charge but I am pretty sure that all six cells are meant to be charging at the same rate. Do I have 3 dead cells ? if I do I will never buy venom again
You only have 3 cells in that battery. The charger shows voltage readings for 6 possible cells, but your battery only has 3 and the readings look perfectly fine on all three. Based on the picture I would say you have a perfectly good battery. A 3S LiPo has 3 cells in Series, so that is why only 3 of the cell voltage readouts on your charger are showing voltage.

Just a quick question, when you compared the milliamps taken by each of your Ni-MH batteries, was your traxxas battery run down in your truck vs. the other batteries simply doing a discharge/charge cycle? If so, it's possible that your truck drains the battery further, possibly accounting for the difference. This isn't for sure, just a possiblity.

Considering this is the third battery with the same problem, I would start looking more closely at the possiblity of a connection problem. Also confirm that the polarity of the new batteries matches the old battery and truck.

TheKennyKiller 08-22-2011 03:52 AM

RE: new batteries not working ... PLEASE HELP!!!
 

ORIGINAL: BigTb17



ORIGINAL: TheKennyKiller

I was going to start another thread but I kinda have the same problem. I just got some Lipos (3s 11.1v) and when I charge one of them and check each individual cell only 3 of them are taking charge. This is my first lipo and it's on it's first charge but I am pretty sure that all six cells are meant to be charging at the same rate. Do I have 3 dead cells ? if I do I will never buy venom again
You only have 3 cells in that battery. The charger shows voltage readings for 6 possible cells, but your battery only has 3 and the readings look perfectly fine on all three. Based on the picture I would say you have a perfectly good battery. A 3S LiPo has 3 cells in Series, so that is why only 3 of the cell voltage readouts on your charger are showing voltage.

Just a quick question, when you compared the milliamps taken by each of your Ni-MH batteries, was your traxxas battery run down in your truck vs. the other batteries simply doing a discharge/charge cycle? If so, it's possible that your truck drains the battery further, possibly accounting for the difference. This isn't for sure, just a possiblity.

Considering this is the third battery with the same problem, I would start looking more closely at the possiblity of a connection problem. Also confirm that the polarity of the new batteries matches the old battery and truck.
Thanks BigT... yes the working battery was run down by the truck vs the discharge by the charger on the other batteries and thanks for pointing out about the 3 cells I feel kinda dumb but it makes perfect sense to me now :) and the polarity is correct as the connection is fool proof. I got a hold of a multimeter and I checked both the battery side and the esc side of the connection and my results are as follows
1200mah 7.2v nimh traxxas battery reads 8.2v
1600mah 7.2v nimh venom battery reads 8.1v
1300mah 11.1v 3s lipo venom battery reads 12.2v

I am really starting to think that the batteries are fine and my problem is with most likely the esc but it still baffles me as to why the 1200mah traxxas battery runs the truck and the others won't :S not sure if I have mentioned this already but all the batteries are new and so is the truck ... thanks again for your reply

BigTb17 08-22-2011 05:54 AM

RE: new batteries not working ... PLEASE HELP!!!
 
No problem.

When you turn the ESC on with any of the new batteries attached it flashes briefly and then goes off again? Is there any way you could check the voltage on the ESC side of the connector when you do this and see if voltage drops or goes away when the ESC first turns on?

Also, if you try to turn the ESC on again without doing anything else (like disconnecting and re-connecting the battery) does it turn on briefly again? Do all three of the new batteries have the new "universal" Venom connector?

Also, the reason I asked about polarity wasn't because I thought you were connecting it wrong, but I've seen a battery wired wrong once (the wires were connected to the plug backwards from standard). But it sounds like that's all good. It was a long shot anyway considering it was happening with multiple batteries.

jester_s1 08-22-2011 05:55 AM

RE: new batteries not working ... PLEASE HELP!!!
 
Yes, your batteries sound like they are fine. That lipo should be at 12.6 fully charged though.

If one battery runs the truck and the others don't, then you just have to figure out what it different about that battery. What you are describing sounds like a connector problem since the stock battery works but the new ones don't. Another possibility is a wiring issue with the BEC.

About a comment you made above: the battery will always take its rated mah if it's fully discharged, even if there is a bad cell. The cells add up in a 3s setup to increase voltage, not capacity. Each cell is 1600 mah and 3.7 volts. When you wire 3 of them in series, you get 1600 mah and 11.1 volts. What probably happened was the battery was not fully discharged, which with a lipo is a good thing. Try not to ever run them all the way down to the low voltage cutoff.

TheKennyKiller 08-22-2011 08:30 AM

RE: new batteries not working ... PLEASE HELP!!!
 
1 Attachment(s)

ORIGINAL: BigTb17

No problem.

When you turn the ESC on with any of the new batteries attached it flashes briefly and then goes off again? Is there any way you could check the voltage on the ESC side of the connector when you do this and see if voltage drops or goes away when the ESC first turns on?

Also, if you try to turn the ESC on again without doing anything else (like disconnecting and re-connecting the battery) does it turn on briefly again? Do all three of the new batteries have the new ''universal'' Venom connector?

Also, the reason I asked about polarity wasn't because I thought you were connecting it wrong, but I've seen a battery wired wrong once (the wires were connected to the plug backwards from standard). But it sounds like that's all good. It was a long shot anyway considering it was happening with multiple batteries.
If I connect any of the problem batteries and turn on the esc I get one quick red flash and then if I try turning the esc on again I get nothing not even a flash and yes all the batteries have the universal plug. I'll include a few pics so you can see the connections and I will also ad the pictures of the batteries that were posted on the website I got them from and as you can see in those pictures they have genuine traxxas plugs. I'll borrow the multimeter from my mate tomorrow and check the voltage as I turn on the esc. thanks for your advice

TheKennyKiller 08-22-2011 11:21 AM

RE: new batteries not working ... PLEASE HELP!!!
 
ok something very interesting just happened. I discharged and charged my lipo three times and then like magic it worked BUT my joy was short lived when I unplugged it and then plugged it back in I got one flash of red and nothing, I'm not sure if the charging had anything to do with it but I am putting it down to those crappy venom universal connections, so I just ordered a few sets of genuine female traxxas plugs and I will solder them onto the venoms to see if that works. If that does work I will consider myself lucky and never use venom again, you shouldn't have to change a plug on a battery that comes with the plug you need that is ridiculous. I will re-post on here when I get the new connectors soldered on and let yawl know if that fixed the problem. Thanks to everyone for your advice, without it I would have been tearing my hair out

TheKennyKiller 08-22-2011 11:38 AM

RE: new batteries not working ... PLEASE HELP!!!
 
sorry another quick update I just noticed a little spark while trying to connect the lipo to the truck, I would not have noticed it had I not just turned off one of the lights in the house so it was a bit dark and it got me thinking has it been sparking the whole time and I only just noticed it ? ... I plugged in the stock battery and everything is fine and no spark so until I get the traxxas connectors I won't be plugging in the venom batteries at all.

Rodney 08-22-2011 12:05 PM

RE: new batteries not working ... PLEASE HELP!!!
 
Yes, your problems sure seem to be connectors. As to that spark you saw, that is pretty typical anytime you connect the battery to the ESC, more obvious with the higher cell counts, when you have 6 cells, it can be quite startling. That is because there is a capacitor on the input to the ESC and when you first connect to it, it is literally a short circuit for the first micro second or so as it starts charging that capacitor. On some of the larger capacity high cell count setups, the operator often installs a secondary connection buffered with a resistor to charge the capacitor before making the final connection to eliminate that spark that can and does erode the contact area on the high current devices.


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