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Hobbyking lipo user going elsewhere!


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When you say they sre in a different league do you mean price wise or quality? I have also just bought some from George, had them the next day, great service and helpful but the proof of the pudding is how they perform and stand up over time. Fingers crossed, will be buying more if they hold up well. 

Edited by martin collins 1
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George’s LiPos seem to be much more robust than the competition albeit slightly bigger and heavier for ostensibly identical capacity.   I suspect he deliberately understates the numbers slightly so they seem to last much longer.

 

Having very good experiences with Optipower too in 4 and 6S.   Not cheap, but when is good cheap?

 

BTC

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2 hours ago, Graeme White said:

Whilst talking about batteries, does anyone know of anywhere with stock of turnigy life batteries or other reasonably priced alternatives? Need something like 2s 2000 and turnigy was giving me this for about £17.

Component shop have some and are showing stock: 

https://www.componentshop.co.uk/6-6v-2000mah-lifepo4-receiver-battery.html

Simon

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8 hours ago, Graeme White said:

I think I did see this but was really put off by it being 3c which seems really low??

True, it does seem to be a lowish C rating but nobody would worry too much about using NiMH batteries and these have a similar rating. 3C gives you 6A and a short term 12A - I would be worried if you ustarted to use more than this, also the futaba/JR type connectors are said to be rated at around 3A so these are probabaly the limiting factor. I use a number of different RX battery types - NiMH, LIFE and LIPO and have little problem with any of them. Whenever possible, I use two smaller batteries with two swtches as a form of redundnacy which also effectively doubles the rating of the plugs.

 

If you really want a high C rated LIFE then Hacker do some (I think West London Models stock them), but they are not cheap.

 

Simon

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14 minutes ago, Simon Clark said:

True, it does seem to be a lowish C rating but nobody would worry too much about using NiMH batteries and these have a similar rating. 3C gives you 6A and a short term 12A - I would be worried if you ustarted to use more than this, also the futaba/JR type connectors are said to be rated at around 3A so these are probabaly the limiting factor. I use a number of different RX battery types - NiMH, LIFE and LIPO and have little problem with any of them. Whenever possible, I use two smaller batteries with two swtches as a form of redundnacy which also effectively doubles the rating of the plugs.

 

If you really want a high C rated LIFE then Hacker do some (I think West London Models stock them), but they are not cheap.

 

Simon

Maybe wrongly, not sure, and I am happy to be corrected. I have been looking at c ratings as a kind of quality control? Higher the c the better the cells and the longer they will last?

 

As you say I don't think I will be anywhere near 6a but when other life are 5 or 10 c which gives more of a buffer. I think I'm just looking for something cheap when things aren't anymore!

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17 hours ago, martin collins 1 said:

When you say they sre in a different league do you mean price wise or quality? I have also just bought some from George, had them the next day, great service and helpful but the proof of the pudding is how they perform and stand up over time. Fingers crossed, will be buying more if they hold up well. 

 

17 hours ago, Martin McIntosh said:

Quality.


How are you measuring “quality” in a lipo at the time or purchase? You certainly can’t take them apart to understand the construction, they are a “black box” product in that sense. All you can really measure is cell balance and (if you have the facility) IR. The former can show up a bad pack from early on, but you can’t extrapolate how long a new well balanced new pack will stay that way purely from cell voltages.
 

IR allows you to calculate a real world C rating (see here), so you know what actual current can be pulled from the pack without damaging it (rather than the exaggerated values given by 99% of manufacturers). What it doesn’t do is tell you much about the likely longevity (cycle life). That is dependent on many things, many of which aren’t in the manufacturers control (discharge rates, storage voltages, temperature of pack during storage and use, etc etc).

 

29 minutes ago, Graeme White said:

Maybe wrongly, not sure, and I am happy to be corrected. I have been looking at c ratings as a kind of quality control? Higher the c the better the cells and the longer they will last?

 

As you say I don't think I will be anywhere near 6a but when other life are 5 or 10 c which gives more of a buffer. I think I'm just looking for something cheap when things aren't anymore!


See above… Whilst a higher C rating indicates a greater ability to deliver current, manufacturers often exaggerate the values hugely and it tells little to nothing about the QA applied to the cells, construction methods or likely cycle life. 

Edited by MattyB
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As has been said, the lifetime of a LiPo battery depends on so many factors that objective comparisons are hard to come by. As for C ratings, they are more an indication of marketing ambition than of quality. I have had experience of high C rating batteries giving good (low) IR readings initially but swelling prematurely, whereas packs of the same brand and capacity with a more modest C rating have held their shape and shown a much more gradual increase in IR.

 

I also find it very hard to assess how quickly a pack is losing useable capacity. If  my (cheap) battery checker tells me that I have 30% remaining after the flight yet the battery is full after a charge of only 30% of its nominal capacity, then has it really lost 40% of its useable capacity? The only way to find out is to discharge the battery on the charger but doing so will shorten the life of the battery so. . . . .

 

Trevor

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I do wonder about the quality versus price question when it comes to Lipos. We hear that brand X from a popular UK based business is of a much better quality that brand Y from one of the on-line 'warehouses' but how much of this is down to consumers feeling the effects of paying more and being comforted by their confidence in 'expensive must be better'.

I remain unconvinced as I doubt whether China has a factory or factories producing quality Lipos on some production lines and elsewhere, lines that concentrate on dollar earning tat. Could they afford to be that selective in production anyway?

I suspect that much of what we buy and the quality of battery that we receive is down to chance, unless the supplier takes the trouble to select out the top tier of batteries by testing and increasing the price for his trouble. We see adverts for 20C, 30C, 60C 100+C...........just how are these figures arrived at and can we really trust any of them?

Most of us understand how to select and run a Lipo for a particular application - However, from experience, I've come across just as many people who don't have a clue and regularly blow up their ESCs and puff Lipos like balloons because they are ignorant of even the most basic electrical knowledge.  Naturally, the brand they're using gets complained about as rubbish and the word is spread to anyone who'll listen.

Quite a few Lipo tests for C rating and IR etc on YouTube and the results are many and varied which only adds to the question.

 

 

Edited by Cuban8
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Presumably the 4 Max ones have a lower IR although I have never bothered to measure it. Against a Zippy Compact pack of the same capacity and C rating I have found that I get considerably higher power over a longer period. Not trying to say that the capacity is any different but the voltage remains more constant over the discharge curve.

I recently had to test fly seven Rxs using a 3S 2200 and did not need a second pack.

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14 hours ago, Bruce Collinson said:

Having very good experiences with Optipower too in 4 and 6S.   Not cheap, but when is good cheap?

 

The RCHotel uses (or at least used-I've not been since Covid, hopefully I'll get back this year) Optipower. Typically these last one or two seasons, being charged 5-6 times a day , 7 days a week over 6 months, including those used in EDF's. Turnegys in that environment when Spiros tried them (and sometimes left by guests after a visit) generally expire within a couple of weeks.

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8 hours ago, Cuban8 said:

I remain unconvinced as I doubt whether China has a factory or factories producing quality Lipos on some production lines and elsewhere, lines that concentrate on dollar earning tat. Could they afford to be that selective in production anyway?

 

 

You are probably correct, but something like a lipo will vary in manufacturing, but if the customer has good quality control and specified an acceptance criteria then they should be able to achieve a consistent standard.

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12 hours ago, Frank Skilbeck said:

 

You are probably correct, but something like a lipo will vary in manufacturing, but if the customer has good quality control and specified an acceptance criteria then they should be able to achieve a consistent standard.

This is how I understand it to be Frank.

 

I have a friend who works in the industry who has travelled on business to China to develop model related things. He told me that they will manufacture products to the spec required by the customer, although reaching said customer spec is not always easy for them as they don't see "quality" in the same as we do in the west.

 

With specific regard to lipos I gather it's a question of selecting and matching the individual cells that make up a lipo more stringently along with a few other tweeks in production. 

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14 hours ago, Frank Skilbeck said:

 

You are probably correct, but something like a lipo will vary in manufacturing, but if the customer has good quality control and specified an acceptance criteria then they should be able to achieve a consistent standard.

Agreed. The problem is for the consumer to be able to discriminate between levels of quality for the intended use of the item.

C ratings provided on the battery labels are no guide to be relied upon in most cases and retailers will simply follow what's on the battery label. I've always allowed a large amount of error to allow for over optimistic battery claims and because most of my smaller electric models are only modestly powered ( I do have a couple of larger 6S 1000W+ types though) battery quality for sport flying has been less of an issue.

The massive price increase of Lipos means that one can't just take a chance on a product being suitable when seeking an alternative source - not so bad when a standard sport type 2200 3S was around the £15 mark a few years back, but I've seen that size of battery on sale for three times that now.

The situation is even worse with larger batteries. Not a good position for the hobby to cope with, and as with a number of other non-modelling products, sales and as a consequence, businesses will begin to come under pressure as some customers modify their needs and spending habits to suit their situation.

I don't mind admitting that although I could do with several new packs to replaced some tired units, for the time being laying out a couple of hundred quid in the present climate for things that did only cost a third or so of that recently and only compounded by some crazy shipping charges,  is not on at the moment. A personal decision of course.

 

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3 hours ago, Steve Colman said:

I have a friend who works in the industry who has travelled on business to China to develop model related things. He told me that they will manufacture products to the spec required by the customer, although reaching said customer spec is not always easy for them as they don't see "quality" in the same as we do in the west.

 

I think that this comment, perhaps paints an unfair picture of Chinese manufacturing quality. Before I retired, I spent around 25 years visiting and working with various Chinese factories. I have had some very detailed looks at manufacturing and quality system. It is absolutely right that they will give you what you ask for and if you uask for the wrong thing, then you will get the wrong thing. I have seen dozens of factories ranging from tiny outfits in just a couple of rooms, to huge factories with tens of thousands of workers on site and there is a similar variation in approaches to quality systems. Of all the factoires around the world that i have seen, the ones with the worst quality systems have been Chinese (although a couple in UK and Italy have been close) BUT also the two with the best systems by far are also Chinese. You can get cheap rubbish anywhere in the world, and you can also get superb stuff anywhere, you just need to be careful about what you ask for and how you check it.  

 

SImon

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I couldn't agree more, Simon.  A very good friend of mine was a senior engineering manager at Rolls-Royce and spent the last 3/4 years of his career setting up a manufacturing facility in Xian (where the terra cotta army is).  Royce's are required and thus demand the highest standards of quality control and the Xian factory supplied it. 

 

China can rightfully be accused of a lot of bad things but engineering innovation and skills is not one of them.  You only have to look at our own limited sphere of interest here.

 

Sadly, my friend died of prostate cancer 3 years ago but there were some very complimentary emails read out at his funeral from his former Chinese colleagues and he visited several times after he retired.

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As is always so. Remember electronic components tested for 10 hours before installation, in stuff that the user REALY does not want to fail. 
QC costs, user decides if it’s worth it. User also has to know that cost does not equal quality if the supplier is a con artist. 

 

Different note, Optipower used by RC Hotel, page up in this thread, is there any reason why hard used stuff that holds up well, as it seems to do here, would not give long service in longer ownership but less intensive use. 
 

ie, as most of use use it.

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17 hours ago, Don Fry said:

Different note, Optipower used by RC Hotel, page up in this thread, is there any reason why hard used stuff that holds up well, as it seems to do here, would not give long service in longer ownership but less intensive use. 
 

ie, as most of use use it.

 

Cells have a shelf life. Capacity drops with time. The chemistry degrades all by its lonesome, without interference from man. And that with the best of intentions and the best of maintenance. Something to bear in mind?

 

All the above points about QC are bob on, cell selection / matching simply costs time at the factory; broad brush overspeccing also works, but equally has a cost (and for lipos, size/weight) impact.

 

Cheap, fast, reliable, pick any two.

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23 minutes ago, Peter Miller said:

As I have mentioned in another thread...or maybe the early stages of this one  Amazon sell lipos. 

They also do a lot of other R/C related stuff

 

 

Amazon's Sunpadow packs are reasonably priced considering what you can pay elsewhere, and from what I've found from a little internet research, Sunpadow packs are favoured by the model car racing  fraternity in the US. I guess the only way to find out re their quality is to buy a pack or two. 2250mA 3S 25C  for fifteen quid including free next day delivery (Prime customers) is worth a punt.

Similar packs are available from Overlander for a couple of  pounds more per item but with a five pound courier delivery charge............one pays one's money etc.

Edited by Cuban8
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2 hours ago, Nigel R said:

 

Cells have a shelf life. Capacity drops with time. The chemistry degrades all by its lonesome, without interference from man. And that with the best of intentions and the best of maintenance. Something to bear in mind?...

This happens at a greater rate with increased temperature and state of charge. The higher the state of charge i.e. the higher the voltage, the faster side-reactions take place between the chemicals in the cell that degrade its performance. Chemical reactions run twice as fast with each 10°C rise in temperature. The best possible storage conditions are a low state of charge and as cool as possible but not frozen.

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48 minutes ago, Andy Stephenson said:

This happens at a greater rate with increased temperature and state of charge. The higher the state of charge i.e. the higher the voltage, the faster side-reactions take place between the chemicals in the cell that degrade its performance. Chemical reactions run twice as fast with each 10°C rise in temperature. The best possible storage conditions are a low state of charge and as cool as possible but not frozen.

 

I agree that Lipos will dgerade whatever happens and that the worst thing is to store fully charged but I do not think it is best to store at a low charge status and as cool as possible. lipos will suffer with having a low state of charge as well as a high state of charge. Most manufacturers of Lipos recommend storing at around 3-8- 3.85V / cell (around 50% charge state) and at around 20 deg C and warn against any other charge state or being hotter or colder than this. Most modern chargers have a storage function that take the battery to around 3.85V / cell. 

 

The time that I really ruined some Lipos was caused by leaving fully charged over the winter months when it got very cold in my garage. Siince then, I have religeously put all my Lipos into sotrage state if I am not going to use for more than a day.

 

Simon

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