should the brca abandon the electric board homologation list?

[wookieewonder]

I'm your typical on a shoestring racer. Been using Turnigy (dirtiest word in rc racing) everything for over 2 years. Motor , servo, esc , Lipo , charger, tools all Turnigy Trackstar / nano tech A spec. None of it has ever let me down . I've even reverse polled the esc/Lipo, fine no problems. I own just one nano tech Lipo , charge it between every heat. no balance problems or puffing in 2 years . Maybe I've been lucky with their products. I do agree their customer support is non-existent though!

[DynaMight]

I wish I held off buying my new batteries now.

I recently upgraded my car so required all new batteries, previously I had some Turnigy stick batteries, not the A-Spec ones, just normal Nano-tech, and they had been fine. Not swelled in over a year, great for the £20 I paid.

I didnt want to spend lots of cash on new batteries and wanted BRCA legal ones to save hassle if I did BRCA events, plus there was some talk about one of my local clubs going BRCA legal only! so I went with some GensAce saddle packs.

My old batteries were 5300mAh 30c, the GensAce were 4800mAh 25c but hell, they drain quickly! I have to do two races on one pack and for the past year, the packs went down to 7.8v after two races, so almost perfect storage charge but plenty of juice left if required.

After just one race the GensAce are about 7.7v! although thankfully they do just about manage 2 races but means I cant do any laps prior to the heat just incase. I'm pretty sure those 500mAh difference between the two batteries isnt the whole reason.

if only I had waited, I could have had 6000mAh 90c battery for an extra £8

[K-Brewer]

If ur on about the 6000mah gens ace ive heard they are to tall to fit in most cars

[DarkHawk]

Originally Posted by alex97

It shows the poor quality of the battery's, ive had four sets of nano tec saddle packs and within 4 months they had both started to puff. They were balance charged and store charged everytime. This really put me to off the nano tec batterys.

I've had a set of £24 gens ace saddles for the last 15 months and there is zero sign of them puffing and they still feel good.

The QC at Hobbyking is very poor as is the quality a lot of their products.

I know a lot of people who run these batteries with no problems and you have to remember all lipo can puff.

[mark christopher]

Originally Posted by wookieewonder

http://www.hobbyking.co.uk/hobbyking...Approved_.html

Shorty pack £27 .07p from the UK warehouse

I take it older versions, ie nano A spec are still not approved?

Believe it or not only the batteries shown on the list are all legal from 1april (for the new additions)

[mattr]

Funny really, the only batteries I've had puff were my two most expensive, approved packs.
An Intellect saddle and an Orion saddle.
My cheap nasty turnigys and gens ace have been fine. Quite a few are on their second owner (or third) and still going strong.

[mpg200]

I have been reading this thread since the beginning, and while I initially voted yes, I changed my mind and can see why the list is there. Being able to see the common sense of the arguments in the fog of forum dribble took some doing but I made it. Some very well put arguments. But rather than do nothing, I wrote to hobbyking and suggested they submit batteries for homologation. I explained to them about the BRCA list and the potential market they were missing out on. So while I have no idea whether my correspondence made a difference, I am feeling a bit smug. The point is rather than rant about it, do something about it. It may be that because of this thread hobbyking received a torrent of emails asking for homologation.

[dazp83]

I messaged them as well, got something back about sponsorship.

[JCJC]

I asked as well, guess a few of us encouraged them, lets hope they can see the system works for them and that these batteries are easy for racers to get.

5mm bullets seem to be available (sample)

[h0m3sy]

If it ain't broke then don't try and fix it

[zoaman]

well I think that the brca should take a fresh look at the batteries already listed. I have bought several lrp 1s saddles recently and have had to have them all replaced.then 3/4 weeks down the road same again swelling and really swelling.1 discharge per Friday night then recharged the following week after storage.so £65+ for them I will defo go with a cheaper brand and take my chances

[xfactor]

Originally Posted by zoaman

well I think that the brca should take a fresh look at the batteries already listed. I have bought several lrp 1s saddles recently and have had to have them all replaced.then 3/4 weeks down the road same again swelling and really swelling.1 discharge per Friday night then recharged the following week after storage.so £65+ for them I will defo go with a cheaper brand and take my chances

Totally agree,

I had two 2s LRP shorty packs swell after 1 charge at 4amps. I have used nano-tech now for nearly a year and are the same size as when purchased and less than half the price. If it means I cant do regionals then so be it, but would rather my house stay in one piece as the ones on the list I wont be buying again..........

[CHEVY]

Got 2 1s lrp 6300 discharge at 7amp down to 3.6-7 for storage voltage
no problem with swelling had problem with reedy 1s

[HOTSHOT III]

Originally Posted by dazp83

Just the ultimates, don't forget they have 5mm bullets. But you can solder in a 4mm female bullet.

Mine came with 5mm-4mm adaptors so you can retain your 4mm ESC/charging connectors if you wish

I got some 5mm connectors at the same time but i'll be using the adaptors until the batteries are all broken in and i'm happy with them

[dazp83]

Yeah so did mine, the ultimates are really good batteries. Had my sv2 flipping over and my other batteries didn't do it.

[SlowOne]

Pointing at the BRCA and its list is like saying you won't buy a Subaru homologated (listed) rally car because McRae crashed one!

Puffing of LiPos is inevitable - there is nothing you can do to stop it. The process of manufacturing guarantees that because of variations in the chemistry of the LiPo that cannot be controlled perfectly dendrites will grow, they will penetrate the insulators, there will be local gassing and the LiPo will puff.

It doesn't matter who makes it, who puts a case and label around it or who puts it on what list, puffing of LiPos happens all the time and cannot be stopped. That is especially likely in our LiPo construction where everything is at its limits because of the discharge rates we want for racing. Consider what making a LiPo involves in terms of process control in manufacturing...

Lithium-ion cell separators most commonly are porous polyethylene, polypropylene, or composite polyethylene / polypropylene films. These films are typically on the order of 20 um (0.0007”) thick, although thinner (approximately 10 um or 0.0004”) and thicker films can be found (approximately
40 um). That’s 1/3 the thickness of a human hair!

If you'll forgive the technical novel...

Any number of minor defects on a cell anode can cause very localized lithium plating. A few examples include a scratch in the anode, a point of anode delamination, a point of anode over-compression, a thin spot in the anode, or a point where a metallic contaminant has plated. Such lithium plating results in the formation of lithium dendrites (hard crystals) and a mat of “dead lithium” composed of detached lithium dendrites.

Individual dendrite shorting is usually not significant, as resistive heating quickly breaks the dendrite. Resistive heating melts the separator locally which quickly heals over and prevents a dead short. That's one source of the gas that causes the puffing. However, if such shorting and heating occurs in the midst of a mat of dead lithium, it may be possible to ignite sufficient material to initiate an internal short of sufficient size to cause cell thermal runaway.

The amount of plated lithium needed for these situations is tiny - in the microgram region - and will have negligible effect on the behavior of the cell once thermal runaway is initiated. One important aspect of this lithium plating failure mechanism is that lithium dendrite growth only occurs during cell charging, since charging is accomplished by moving lithium ions (Li+) and electrons from the cathode to the anode.

Puffing is a sign that the cell is now not in the best of health and it is really good to see people taking this seriously and replacing their cells.

There's no point in blaming the list or the manufacturers - it is the technology we demand and the inability of the manufacturing process to be perfect all the time that leads to puffing.

Look back to the NiMh cells and ask yourself how many you and to buy in one season to be competitive and (at the end of the development cycle) how many just died on you. You couldn't buy competitive NiMh cells for less than £60 a pack and you'd be lucky if they stayed competitive for half a season and you didn't have the capacity to run flat out for any race length in any class. And as for the maintenance regime...!

Now you have competitive cells that cost around £50 to be competitive, last up to two seasons and take no complex maintenance. In order that they are made to a standard that gives the greatest amount of protection and standardisation to the user through limits on size, enclosure and price, there is a (BRCA) list.

The price you pay for that value, simplicity and standardisation is that some will puff and you have to replace them. Complain all we like, the answer is to suck it up as that is the price we have to pay for this technology.

I hope that helps understand why cells puff and why the list helps us. It seems our inventive people are finding lower-cost competitive alternatives that might not be at the cutting edge of the technology, but as a result are more robust in use. Go for it!!

[zoaman]

well all this may be true.but im no chemist yet I do know that after only 4weeks and 6 set of saddles @ £65. per set .and no they wont change them again they say. I feel that some body needs to take a closer look.cheap batteries doing the job (and there is loads of people on here saying that) yet expensive one failing.which way do you think most folk will go. if the cheap ones live up to it y not use them

[SlowOne]

Correct - your post shows you are not a chemist!

No one needs to take a look at it. People need to be informed and understand the situation. I'll make it simpler - if you go for the highest performing version of anything it is more likely to fail than if you go for something that performs at a lower level and is more robust.

We are not victims of some great conspiracy, we are adults who take responsibility for our actions. No one needs to do anything for us here, we need to do it for ourselves. It matters not which way folks go, the market will sort itself out based on the actions of the customers.

If you want information, isn't that what Oople is for?!!