mewanderinghome said:
barbarossa said:
i made the battery teardown of my original 48 volts 13s6p battery (LG MJ1 cells).
i am disappointed about the original built.
several strips had a little rust:
rust.JPG
this means this strip is not pure nickel but nickel plated steel.
nickel plated steel is a horrible conductor and for that reason gets really hot.
yep, the top isolation melted a little. of course it melted at the serial connections because the serial connections i have seen inside the battery were only 2 nickel strips (sometimes more layers per strip connection but not always). 15 amps per strip thats too much for a normal pure nickel strip in that size. but it is dangerous using nickel plated steel (!)
Thanks Barbarossa as always for your detailed findings regarding this bike. I bought one in the group buy in early January, and so I'm still waiting for it (production has been delayed by production slowdowns due to covid-19). It doesn't seem like Ivy or Grace monitor this thread as closely as Ivy used to, so I brought this potentially dangerous finding to Grace's attention. I asked Grace if Frey builds their own battery, and if so would they fix this inexpensively resolved issue for the bikes to be delivered in the group buy. Her response:
"we build the battery. Well, after check with our Tech Department, the issue you mentioned don't have now, that is our old AM1000 version 2.0 or 3.0, now we already updated the frame and battery case in 5.0 version, the compatibility and the precision are very good, so don't worry about it."
I've asked her about 1 bazillion questions since placing my order, so don't really want to bug her any further about it, but I do wish I knew for sure she fully understood the question and specifically addressed whether the strips are now solid nickel or still the inadequate nickel-plated steel. If anyone else wants to call her attention to it too (and ask that specific question), it might help make sure Frey addresses this potentially dangerous but inexpensively resolved issue, since they do build their own batteries.
PS- since they build their own batteries I also asked Grace if I could get the smaller 48v 17.4ah battery in the slimmer-profile Reention Dorado Plus case instead of the bulbous Dorado Max, and Grace said they're now using the Dorado Plus case for the smaller battery. So I'm hopeful I won't have that unnecessarily-wide Dorado Max case that sticks out from the frame on the left side. I'll let you know when I get the bike (end of May probably

) so that mystery can finally be resolved
hi again, mewanderinghome !
mmmhhhh... i know what you mean: is this problem really addressed ? Or it is even considered as a problem ?
design of the battery case did not really change since years - meaning my old battery is identical to my new battery case that i bought a few months ago. except some minor changes concerning the upper plastic end.
but hey it is not a rocket science.
i would say 3 inexpensive things are important:
1) of course only pure nickel strips should be used.
2) serial connections should be 3 layers of pure nickel for each cell group instead of one. here 2 original serial connections - connecting 2 battery blocks with each other:
serial.JPG
3) negative and positive pole should be 3 or 4 layers. have a look at my negative and positive pole of my original 48v battery, the negative pole's PVC melted a little, too hot for all current going through :
positive_negative_pole.JPG
after all it is a solid handmade battery - no obvious risks of short circuits or something like that - only the weak connections are not really nice. i can forgive many problems but these little cells are not toys. maybe the risk is not really high but doing things a little better is never the wrong way. and that is the advantage of Frey i think - Frey communicates and is willing to learn - nobody is perfect.
but hey, you will get your desired smaller battery
only downside, with Reention Dorado plus the Speedict Neptune 15 BMS might not fit - as most (even small) BMS won't. it would be interesting to see which BMS Frey uses with that smaller Reention Dorado plus. there is not much room inside. Neptune 15 has the same dimensions as the original BMS of my 48v battery had - only difference it is a little thicker. and even with Dorado Max battery it is a tight fit.
bms.JPG