Maxxamps batt always out of balance

[lincpimp]

Originally Posted by BrianG

Guys, let's keep the MA-bashing posts down. Stick to facts and observations.

Good point, big guy!

I will add one more thing that is pretty good info for all lipo choices. Lipo construction is pretty much universal, so cell dimension and weight are pretty good comparison info when looking at various cells. If both cells are the same size and weight, and one is rated higher you may want to take a step back and ask why... Since I have handled a bunch of various pack cells I have seen the maxamps 4000 mah "20c" cells grow in thickness and in weight over the last 2-3 years. So I guess it got better? Not sure as I still get 8000 packs (4000 cells in paralleled pairs) that puff one or more cells.

The puffing is due to poor cell construction, either materials or testing (or whatever they do). Matching also comes into play, but maxamps has always said that they match the cells. If so then all of the problems are due to a cheap cell that has varying quality issues during the manufacturing process.

Comparing MA's 4000 cell to a similar polyquest cell (older 20c series) the cells were thinner and lighter. So the capacity may be correct (easy to measure that, discharge the pack to lvc and record what it takes to charge fully) but I doubt the C rating is.

I also directly compared MA 5000 pack with a polyrc (enerland) 3700 25c pack And found the polyrc pack could outperform the MA in runtime and punch. Turned out the 5k MA pack could not even deliver the rated mah under the load I had on it, where the polyrc had no issues. These cells should have similar amp output capabilities given the specs, and the 5k MA should have had the advantage on runtime. Pack weights and dimensions were very close with these 2 packs, so I deduce that the MA 5k cells were more like 5000mah 10-12c given the performance.

Bottom line is that people get greedy and want 8000mah packs (MA even base some of their advertising on this) and think that the rated specs will be enough to push a buggy or truggy around on 4s. 4s is hard on lipos in larger scale stuff, going up to 5-6s is much better. lipos that put out 80-100 amps are just not enough for 4s.

I have some informal testing on alot of cells, so I have a good feel for what works and what does not. Plus having dismantled and reassembled a bunch of packs I have seen the pack construction techniques, some of which leave alot to be desired.

[transtalon]

I agree with lincpimp. I have the Polyrc 4350 and it was taking close to 4200 when I charge it one time. I think Polyrc is not a popular name like Polyquest or Flightpower but they are real good and it outperform my 5S 8K MAXAMPs
but don't have the runtime like the 8K with the 4350 mah 5S Polyrc that I score for 50.00 shipped from the fellow member at Lstforum. It is like new, the best 50.00 I spent.

[lincpimp]

Originally Posted by transtalon

I agree with lincpimp. I have the Polyrc 4350 and it was taking close to 4200 when I charge it one time. I think Polyrc is not a popular name like Polyquest or Flightpower but they are real good and it outperform my 5S 8K MAXAMPs
but don't have the runtime like the 8K with the 4350 mah 5S Polyrc that I score for 50.00 shipped from the fellow member at Lstforum. It is like new, the best 50.00 I spent.

I have bought alot of used enerland based packs, like the polyrc pack you bought. I have never had an issue with them puffing, or having weak cells. I can only remember seeing/hearing about a handful of enerland packs that have had issues, and I am not sure if that was user error or bad cells. Enerland have tight QC or something, and the factory matching is pretty good.

Flight power have a in house matching process, as they buy cells from enerland and assemble them in house. Their packs seem to be the best I have tired, also the most expensive new.

Polyquest are enerlands own brand, and they assemble those packs and sell the direct, that is why HC carries them. All good cells, well worth the cost, especially if you can score a deal like you did!