View Single Post
Old 03-04-2013, 12:30 AM   #383
_cy_ OP
Beastly Adventurer
 
Joined: Sep 2011
Location: Tulsa, Oklahoma
Oddometer: 5,785
Quote:
Originally Posted by JoelWisman View Post
_cy_ This is WAY ahead of actual knowledge. earthX is using nice thick intercel connectors that are 2x what Shorai is using, but they are no stronger then Antigravity. Their case does not appear to be as tough or water proof as Antigravity but I believe I have an early production unit so will reserve judgement. There or so many variables that go into a battery you can trust your life to beyond good warm weather current output and the presence of something that is stated to be a balancing circuit that does not break after a few weeks of testing..



This is indeed modern theory which changes regularly but does not necessarily have bearing beyond a piece of paper that it is written on.
1: I have two 16 cell Antigravity A123 26650 batteries that I buzzed the tops off of for testing individual cell balance via micro volts and low and high rate capacity testing as well as an Antigravity 4 cell and 20 cell. Even on the test units that have cells that are bulging since testing super high current draw, every cell is still balanced better then 1%. These are batteries that have not only been tested in ways that proved destructive to both Shorai and Ballistic but have spent every day since testing in actual modern adventure bikes being used daily. All of these 56 cells have been once again tested for balance in the last two weeks cell by cell and ALL ARE STILL in balance. One 16 cell has been in testing and use for just over a year now and the other 3 batteries have been in testing and use for greater then 7 months.

In what way is a battery with a balance circuit better then one that through imperial data does not need a balance circuit?



In what way is a battery that has a balance circuit better then a battery that does not have one because it does not need one? If you don't need a balance circuit then all the presence of a balance circuit does is create more things that can go wrong compromising the battery on its own?

I have never seen a prismatic cell that didn't need a balance circuit because the nature of the cell being unconfined and vulnerable to being squished and giggled as well as the tendency I have observed for manufacturing tolerance to be larger with large prismatic cells versus the amazingly tight tolerances A123 26650 cells are manufactured to. So... On larger prismatic cells a properly designed and quality manufactured balance circuit is a plus, but it is NOT a plus over a cylindrical circuit that does not need balancing on it's own.



Where are you seeing over-voltage protection on the earthX battery? I may have missed a few electronics engineering classes due to being hung over but am still reasonably certain that I would notice something on a circuit card that could dissipate hundreds of watts or disconnect the battery during an over-voltage event. It isn't there! earthX has no over-voltage protection that I can find.


NOW...... I am absolutely NOT giving earthX a thumbs down, nor a thumbs up. It will take at least a few more months more before I start forming a significant opinion of any kind. The inclusion of a balance circuit is tolerable IF it is well designed and of high quality IF some other advantage is to be had from using prismatic cells. BUT, what actual knowledge do you have that these are good batteries beyond the very first tests that do indeed show the battery can put out current.

Also, how is 4s (4 cells in Series) superior to a greater number of smaller cells in parallel from a real world standpoint? Cells in parallel are virtually never a problem from a balance standpoint because cells in parallel will virtually always balance if if they are low quality. Cells in series are where the balance problem will occur if the cells are not perfectly matched and a 4S-1P battery has the same balance issues all other things being equal as a 4S-5P battery.

Further regardless of weather you are talking the worlds largest prismatic cell or the worlds smallest cylindrical cell, one hard short, one solid dendrite, one breached container and dry out.... will destroy that cell. The difference is if a battery is made up of 4 cells in series and one cell fails then the battery is completely useless. If on the other hand the battery is made up of 4 seriesed stacks of say 4 cells in parallel and one cell hard shorts, then theres a better then even chance that that single cell will pop its current interrupt check out, and you will still have a working battery though a battery with one fourth less capacity that is going to develop a balance problem over time.

4S and one fails, your walking. 4S-4P one cell fails and odds are you can ride out and replace the battery at your convenience.

Once again, I LIKE earthX so far but don't have nearly enough time testing or experience with them in the real world to say they are better or worse, good or bad compared to anything beyond Shorai which every test and real world come back ratios revealed was a piece of junk.

Through intensive and extensive testing AND over 100 sold by my dealership without a single failure I can and do recommend Antigravity batteries. earthX may turn out to be a better battery, better in some applications, not as good, or a piece of junk.

Where _cy_ are you seeing a real world proven advantage of earthX batteries to recommend them beyond a load test and advertising about a balance circuit and what I believe to be the incorrect assumption that they have over-voltage protection?
true enough Earth-X still has to prove it self in long terms tests. overcharge protection is limited to 3 amp on Earth-X balance circuits.

as each cell reaches a set voltage, excess voltage is shunted off until a set point is reached. this allows cells that have not reached cut-off voltage to reach full charge.

balance circuits will not work until full charge is reached. so balance circuit also acts as an overcharge protection circuit within limits. which are 3 amp on Earth-X boards.

provided one doesn't jack up volts to push current into a 4s stack. LiFePO4 cells naturally reduces amount of current it will accept closer it gets to full charge. so a 3 amp limit should be plenty to prevent overcharge within normal charge voltages of a 12v charger.

Antigravity is an excellent battery as proven by your dealership's zero failure rate for Antigravity. but don't underestimate advantage of your recommendation of correct size Antigravity battery for each bike. will the bike be used for Starbuck duties or Adventure bike duties to parts unknown?

IMHO a major reason for failures for LiFePO4 motorcycle batteries is mfg under sizing recommended batteries. the dreaded combo of Cold short motorcycle rides with heated gear will result in a motorcycle that will not start the next morning.

_cy_ screwed with this post 03-04-2013 at 12:44 AM
_cy_ is offline   Reply With Quote