My Hybrid battery LiMn + LiCo

Some weeks ago I purchased some Makita BL1830 packs (used in power tools–>10C max discharge, see previous post).

I tested and recovered them and then made a 15s4p (55.5v 6Ah nominal—>60 cells) pack and tried it on my ebike. It worked great!

IMG_0462.JPG
Makita testing

I then decided to dismantle my 10s12p li-ion pack made with laptop cells and make a hybrid battery with the Makita cells.

I made a 15s3p (55.5v 6Ah nominal –>45 cells) with the laptop cells.

Charged both packs to the exact same voltage (62.0v) and then connected them in parallel.

It took me a lot of time to dismantle the 10s12p pack and rebuild it to fit the battery box but I am pretty happy with the result.

IMG_0480.JPG
Battery box & Hybrid pack

I also added a pre-charge/anti-spark resistor (380 Ohm 3.75W), so far works great on different setups:

hybrid_prech.jpg
Precharge hybrid pack

Bike data:

*Rear Bafang 500W high torque from BMSbattery
*26″ wheels
*30 Amps (32Amps in reality) 36v KU123 controller (63v caps inside)
*GT power meter 130A max (read max 60V but I’ve been lucky, reads my 62v !!)

So I took the bike out for a ride today. Unfortunately I only have 2 Cell-log 8s so I can log the data only from 5 cells of the makita pack and 5 from the laptop pack.

During the ride pedalling was 0%.I tried to go WOT all the time but I was going too fast on the bike path. It was lots of fun, very quick acceleration. I am pretty impressed with the results, after 10km I still hit 40kph+ no problem.

Data:

Fullscreen capture 8252012 71813 PM.bmp.jpg

Fullscreen capture 8252012 72310 PM.bmp.jpg
Notice 45.5kph after 400m (a little downhill though)

Laptop cells log:

Fullscreen capture 8252012 72505 PM.bmp.jpg
Laptop Log

Here I seem to have a problem with a weak laptop cell.

Makita cells log:

Fullscreen capture 8252012 72020 PM.bmp.jpg
Makita log

So far I am pretty impressed with the results. I am not sure about the voltage under load. I read 53.5v during acceleration in the last km of the ride, quickly climbing up to 56-57v (I wish I had a camera to re-view what happened).

I opened a thread on Endless Sphere forum to talk about the results, link: http://endless-sphere.com/forums/viewtopic.php?f=14&t=43127

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s