E-Bikekit.com 36v 10ah LiFePo4 Battery

[Ypedal]

So the fun continues..

Since last friday i have a good dozen cycles on this pack, 10 or so shallow cycles.. and 2 full 100 % drain cycles. They yield a full 10ah at 9 amps.

It's horribly cold and snowy out here in the maritimes so i'm bench testing !

 

[Ypedal]

Closeup of the charger.

UL, CE, FCC, etc.. all the good stuff i like to see..with a polarized plug !! Bonus.

I wanted to open it up but it's a sealed unit, no visible screws behind the sticker.... doh!

Open circuit my DVM says 43.6v
Cycle Analyst confirms 2 amp charge with CV at the end until 200ma then goes to green.

 

[Ypedal]

Supplied pigtail with connector that maches with upcomming controller on new kit.. i removed this connector and replaced it with andersons, everything in my house has andersons, I love those things..

 

[Ypedal]

Goes into the battery pack..

 

[Ypedal]

Glass fuse, 30 amp rating.

 

[Ypedal]

So now.. the nitty gritty.

At 9 amps, the supplied pigtail gets noticably hot. ambient temp was 22 celcius and surface of the wire was measured at 38 celcius after 20 minutes. That's a problem that needs to be dealt with.

Looking at the circuit, I see the glass fuse holder, key switch, thin brass crimps x 2, then the plug male and female, then connector (in my case ansersons ) ..

I'm fairly confident in the 120v type plugs, but the glass fuse and key switch are likely the culprits ..

Would it work as is ? = Yes
Woud it work to my standards ? = Nope...

 

[Ypedal]

Opened up the plug end for inspection.. the wire is low strand stiffy stuff, easy fix, and the screw ends could be soldered for extra measure.. also easy to do.

 

[Toshi]

It looks like the battery Golden Motor sells on their website.

http://goldenmotor.com/

-R

i see that the ebikekit vendor is posting on this thread. so is this battery the same as the goldenmotor.com offering? how does it differ if it's not the same?

 

[Ypedal]

1st thing. i snipped off the bullet connectors and crimped on some andersons directly..

Ran the same 9 amp test.. = No Heat ! 8)

 

[Ypedal]

It looks like the battery Golden Motor sells on their website.

http://goldenmotor.com/

-R

i see that the ebikekit vendor is posting on this thread. so is this battery the same as the goldenmotor.com offering? how does it differ if it's not the same?

That remains to be answered.. i see a different charger for one.. only obvious evidence at this point, other than that time will tell once someone cracks one open..

 

[dogman dan]

Ok Ok you can have an EV and live on a big hill, I do in fact. But bike one wouldn't do it at all. Bike two lasted 400 miles and melted the brushed motor. I took the bus up the hill the rest of the summer, or put the bike on a bike rack on the car that I drove down the hill. Bike three Aotema brushless, still testing, we'll see when the hot weather comes. So far, I haven't had a bike that could reliably climb the hill in all weather.

 

[Ypedal]

You might want to try an X5 next !!!

 

[dogman dan]

I woulda if i coulda. Still trying to recover financially from my other hobby, hot air ballooning. Gotta live cheap and pay down some debt right now. It was worth it, but it had to stop last year. The motor is not so unaffordable, but 30 ah of ping, or 20 ah of headway ,psi or a123, is not happening this year for me.

 

[recumbent]

How do these batteries compare to the PSI cells i see in the photo on the other page.

I'd like to scoop a 48 volt battery pack in a couple months. 10 Amp/hrs is enough for 90% of my rides, but the other 10% are the fun day trips i don't want shortened.

Will E-bikekit have 48 volt boxes? The price for the 36Volt is good, and the appearances are great.

 

[Ypedal]

The PSI cells are in a different class of battery, and also different price range :lol: ( ie: 10C vs 2C discharge rates )

For now, 36v only, there is potential for higher capacity, i've requested that Jason ask his battery source if 2 of these packs can safely be connected in paralell, waiting for info on that once the Chinese New Year holiday ends...

48v opens the door to a host of problems, for one, it takes the peak power above and beyond the 500w guidelines.. too fast for a dealer friendly kit.. and increases size and weight of the pack.. Of course.. nothing says the end user canot add a 12v boost :wink: . Actually, that brings up a 2nd question for the battery source..... more on that later.

Also, for a dealer friendly front wheel kit, 36v is enough imo.. not alot of newcommers understand torque arms and strong forks.. :wink:

 

[recumbent]

The PSI cells are in a different class of battery, and also different price range :lol: ( ie: 10C vs 2C discharge rates )
Also, for a dealer friendly front wheel kit, 36v is enough imo.. not alot of newcommers understand torque arms and strong forks.. :wink:

So true, when i first started 10 years ago it was 36 volts and 1-C NICAD's, it worked fine for many years.

And the 48 volt batteries i have now are only 2-C and they also do the job well, But pulling two skate boarders up a long shallow hill was my limit though

 

[dogman dan]

I find 36v quite adequate, usually enough to get up steep hills at 15 mph, and 20 -25 mph top speed is all I would want to sell as a kit. Being able to paralell the batteries without worrying about diodes and stuff would be great, but for longer range, carrying two and switching halfway is not so hard. If both are mounted, all you'd need to do is plug and unplug, 10 seconds max.

 

[GamesMedic]

Do those batteries come in 48 volt varieties? How much did the pack cost? Golden motor charges a small fortune.
I just put a 1000 watt system together from Golden Motor. Works great.

GamesMedic

 

[Ypedal]

Time for an update !

After some more poking and probing.. I found that the wires on the removable pigtail were not very well secured to the Male side of the external wire... without any real force both the + and - sides simply twisted right off by hand..

Went digging in one of my parts bin, found a 12" long piece of 12 or 14 gauge stranded wire, see picture for difference in wire strands !

 

[Ypedal]

Slipped the rubber boot from the original onto the new wire and hot-glued it to prevent water from working it's way into the wire and into the connector.

 

[Ypedal]

Nermind the screws.. Soldered them suckers in there....

 

[Ypedal]

Other side.

 

[Ypedal]

It's a tight fit, but i get'er in there.. Had to flatten out the metal tab to accomodate the thicker wire..

 

[Ypedal]

Now.. there are a few ways to deal with the heat issue.

1- Do nothing and live with the heat. At 10 amps constant ( on 36v = 360w ) it will hold up but at 20 amps i fear the connectors would start to get soft on a moderate to long ride.. and that's not good enough.

2- Bypass the internal fuse and key part of the circuit, running the wires directly from the BMS to the pack's stock plug. Fix the pigtail as detailed above and call it good.

3- Drill a hole in the black plastic end, next to the pack's stock plug, install a gromet, run 12 gauge wire with andersons to the BMS wires to bypass the fuse, key, and stock plug. This would be my personal preference, leaves a permanent wire dangling form the pack so care must be taken when setting it down not to crush that wire.. but would not really be a problem.

For now, i want to test the heat factor with the fuse and key, so andersons it is !

When dealing with fairly thin wire and PP30 tips, strip double the lenght of wire, twist and bend it over on itself , makes more copper inside the barrel of th PP30 tips for a better crimp.

 

[Ypedal]

For those of you using the 10$ cheapie vice type tool for Andersons.. some things i do to make life easy..

Red and Yellow represent 90 degree, the Green line shows the angle i place the PP30 tip into the vice.. if the seam on the PP30 is not centered with the hump on the vice, it will not fold in properly...