Sattelite hacking was all but stopped when they introduced NDS and Irdeto2. That was my hobby for about 5 years. But it pretty much ended a year or so ago.


Charles

I know you guys arn't the least bit interested in Trivia. But I will post it anyway.

I decided to compare the Raw RC3600's to the Raw IB4200's at a 20 Amp discharge current.

As expected the IB4200's had a higher average voltage over the full discharge cycle.

But, It was a lot closer than I expected for one of the IB4200 packs. The first IB4200 pack was only 1.7 mV per cell higher than the RC3600's And they were 17.7 mV per cell higher on the other IB4200 pack. And again the Lower capacity IB4200 had the Higher average voltage.

Of course the IB4200's had about a %30 longer runtime.

I know I need to say this every message because people still insist on telling me what I am saying and not looking at what I am writing.

The IB4200's will have FAR supperior performance on the track. Simply because they have a higher capacity. A higher capacity means they wont be discharged as much by the end of the race. And since they are not discharged as much they will have a notably higher average voltage over the whole race time. And this higher average voltage means higher average Lap Times.


Charles

On the other topic of Cells exploding violently I am still searching. Just doing a general search on the Net I got no examples of any NiCD or NiMH cell exploding violently.

Their is however MANY cases of LiPo cells catching on fire in Mobile phones. And a couple of examples of CR123 Lithium primary cells exploding mildly and exhausting much smoke.

I will have to narrow my search down more and start looking only at RC forums. But to date it has only been 2 manufacturers that people have said exploded violently. About 4 examples so far. No doubt this will change when I start looking only at RC forums.


Charles

Your searching skills might need updating.
If you try searching on "exploding battery" in rctech you will find this thread
(hopefully the link is correct)

http://www.rctech.net/forum/showthre...loding+battery

This happened at the National Off Roads last year in Perth. Their is even a link to the photos.

and another from rctech

http://www.rctech.net/forum/showthre...loding+battery

and another

http://www.rctech.net/forum/showthre...loding+battery

It also happened at the Whalan track about a month before Chrissy and shot the casing from one side of the pit area to the other just missing my son and some other kids playing . Mate i'll tell you they go off with a bang . A few of the guy's there that day should be able to confirm this. I actually picked up the casing when it landed and handed it back. It had everybody saying WTF was that

Yes I have found a number of them now. Thankyou for the links.

But they seem to be either IB's or GP's.

Does anyone have any links to other brands of batteries exploding violently. I want to get a pretty good idea of what brands are exploding more violently and more often than other brands.

In the past this sort of thing was very rare. At least the severity of the explosion. Many batteries have vented violently in the past but almost no reports of Violent explosions.

If the explosions are gettimg more violent it could mean the design of the Vent valves is not allowing the preasure inside the cell to be vented before it explodes.


Charles

What has happened to the data sheets from Intellect's web pages ?. I am trying to get the data sheet for their SC3600 Cell. I have the one for their SC4200 but cant find any of them anymore.

The reason is I have now purchased 6 Raw SC3600 cells so I can do a fair comparison with the Raw Sanyo RC3600HV cells. (Apples with Apples as some put it).

Initial results of the SC3600 are quite poor. The Internal resistance is considerably higher than the RC3600HV's and the Average voltage on a 10 Amp discharge was noticably lower. The Run time was about the same.

Also, Just for a laugh. Someone posted a message saying Sanyo cells were only good for Battery Powered tools. Well this is what I found on IB's web page about the SC3600.


Key Specifications/Special Features:

SC size NI-Mh rechargeable battery
Up to 3600mAh
High rate discharge up to 20C
Widely used for R/C toys and power tools



I have also checked into why the RC Plane guy's are using the RC3600HV's and not the GP3600 or IB3600's. And I was correct with my guess. The Sanyo cells are lighter. And with planes weight is always a problem.


Charles

On thinking a while I removed this message about CE certifiction. Could cause too many negative/angry/abusive responses.


Charles

This seems to a very serious trend that is appearing recently with these new high capacity cells. I am sure we all hope that no-one is serioulsy injured.


Charles

What you will find is that the new cells are charged at a higher rate, thus putin a high load onto the cell. The container that is made to hold the inners is appox the same as the lower capacity cells. You get a lot more stress on the cell , so when they let go, they go with a bang in general.

The old cells wont take that tpye of stress so vent a lot sooner.

Good to see you picked up on the series i put in.

But the load rating of the the cells is still much higher than the lower capacity cells.

The reason you have been tormented by he statement that the sanyo have the same discharge rate at 10 amps, is So What?? They dont perform on the track. Again you stated the the IB cells would perform better on the track.
But 10 amp discharge is not the track, we know this so why compare the 2?? It makes no sense to compare them, the IB are a better cell.

Simon

It was probably a silly thing to do in the first place to compare a 3600 mAh cell to a 4200 mAh cell. But that was the only IB cells I had at the time. I was trying to show the Quality differance of the cells as apposed to the Performance of the cells. They are not always the same thing. Some people had a hard time understanding the differance and kept accusing me of saying the Sanyo's were better. In fact I said many times the IB4200's perform better on the track purly because they have a higher capacity. And I still stand by my comment that the Sanyo's are a higher quality cell. Even though the IB4200's are winning races.

The problem with these new cells and the container exploding violently appears to be that the Vent valve is not opening soon enough. By the time the Vent valve has opened it's too late and a very violent explosion of the case occurs. The reason they have vent valves is to stop the case from exploding like this.

As for charging them at a higher rate that is %100 true that it puts higher stress on the cells. I would suggest that people charging at these very high rates have a look at the Intellect Web page. They give you some pointers on how to look after the cell. The Most important one is they tell you to use a Temperature sensor and make sure it cuts out below 55 Degrees C. They also say to only fast charge them at 2-4 amps.

Remember it is Heat that kills NiMH cells Much Much sooner than NiCD cells. NiCD cells can take quite a beating compared to NiMH cells. NiCD cells are a much safer cell. They just cant make them in such high capacities which means they are uselss nowdays for racing.

I have not had a problem fast charging the Sanyo cells. They are at a lower temperature after charging. And also a lower temperature when discharging at high currents. I used to charge my 7 year old RC3000's at 5 amps and never had any problems with them.

I just finished my proper tests with the RC3600HV and SC3600. I did find one thing rather concerning. The SC3600's got very hot during discharging at 20 amps. I got worried and starting cooling them. Even with added cooling they still hit over 55 Degrees case temperature. The RC3600HV's at the same discharge current with no addeed cooling only hit 47.2 degrees peak.

This higher temperature is probably caused by the internal resistance of the cell. The higher the internal resistance the more heat is generated inside the cell. And the IB's do have a higher Internal resistance to Sanyo. Even the RC3600HV has a lower Internal resistance compared to the SC4200.

I do feel that Zapping the cells is a must. It benifits the cell by lowering the internal resistance (According to the experts this doesnt damage the cell). Which helps in two ways. 1. Lower Running Temperature. 2. Higher average volts. I am yet to be convinced that Matching at very high currents is a good idea. It does extreamly stress the cell. And the cell can fail some time after matching. Matching at a lower current still gives as good a matched set but doesnt stress the cell to the extreme. Matching at these rates surly must be going above the manufactures recommended cutout temperature of less than 55 degrees C.

Anyway, Here are my test results of a Fair test of Raw cells. RC3600HV vs SC3600.

Note, The Internal resistance was measured using the generaly accepted method of a 1khz 1 Amp square wave.

Charles

Charles,

I do not know why you are playing with the SC3600. Although you are doing it for a comparison with the SANYO, Intellect gave up on making this as a competition cell neraly two years ago.

As for planes and boats where weight and power to weight is required there is currently only one choice ... the IB4200 cell has no competitor. Its performance far outweighs any other cell on the market according to these guys. A 3600 maybe in a glider but not a high powered plane or boat

For F@%*'s sake Charles,

At 4 lines, NickM probably reads more of your rants than most. However as I was scrolling past your latest techo rant, I am so glad I picked this bit up!

WTF! "According to the experts ... " The whole point of this "Know Nothing Rant" thread is that you refuse to listen to the experts and don't want anybody else to either!

Do something really useful for the world. Stop posting missinformation here, junk the Sanyos, buy a decent battery pack, get to your local track, be human, have fun, but most importantly, "Don't mention the Sanyos!"