Upgrading a Motorino XPd

[inedible]

To be fair, that's not actually my heating pad, it's one of the stock models offered by this company I found on ebay: http://www.ebay.com/usr/keenovo

They sell a bunch of normal sizes, or they can design something to your specifications. So, I'm going with 0.1W/cm^2, 60v, one 7x9" and two 4x9" ones. 40W for the one, 20W each for the other two. They're going to be rugged silicone rubber with the thermal sensor embededd within the rubber, not like the one above which is cloth, with the sensor taped to the outside. I haven't ordered it yet, I'm still working out the details with the seller.

It'll be $75 for the set, but hopefully they'll get me through a few winters to come.

PS: Thanks for the compliments! Your thread about your motorino inspired me to get mine in the first place. I always admired your DIY spirit in building your own battery pack, fixing problems that came up, slowly upgrading different parts, etc. These bikes really are chinese garbage underneath everything, but they're at least pretty solidly built and a good platform to tinker with and improve.

 

[inedible]

After having my bike inside my room for a month while I waited for parts in the mail I finally took it for a spin today. First time since installing the BMS, so up until now I'd never seen what amperage the bike is drawing. I'm surprised to say, it tripped the 60A over-discharge alarm when I was going up a curb, meaning it was drawing more than 4kW! I'll have to set that higher, though that's the max recommended current for this BMS. And this is *after* I took the solder blob off of my shunts!

Got the new snow tire on, works a treat. I can actually get started from a standstill without just spinning my tire, which is nice. Installed the LED headlights, which are brighter than the old ones, but draw only some ~5W when the old ones took 70W+.

I'm glad to say, I also got regenerative braking working again! So the way it works is the controller disables regen when your battery voltage is too far above 48V, for safety reasons, which is totally reasonable. But, until recently I thought it was measuring the voltage from the main big power wires. It turns out it's measuring that voltage from the "on" line, coming off of the "ignition" keyswitch.

So, I ran a line to cell #12 to provide the 48V, and ran it through a relay that runs off of my 12v system. Now, the controller sees 48V on the "on" line, and all is well in the world. Surprisingly I've seen it charging as hard as 24A when braking down a hill.

I've still got a lot to do though. I still have no idea where I'm going to put this bigass LCD for the BMS. I've bought a bluetooth-to-serial adapter for it, so hopefully I'll be able to use an android app to monitor my battery instead of cutting a hole in the body then trying to make a waterproofed lexan window for it etc. Still haven't bought a heating pad. Still haven't upgraded my phase wires, put the temperature probe in my motor or battery or controller, etc, etc. I may just put that all off until spring.

 

[mistercrash]

Ok so here's the wiring diagram for the XP series scooters. Show me you're drawing skills and teach me how to wire this line from the #12 cell to a relay that runs off of the 12V system.

My battery is made of four 4S modules in series for 16S total of Lithium Ion. I don't have a BMS so I'm guessing the #12 cell would be the positive of number three 4S module?

 

[inedible]

Here you go:

The 12v system turns on the relay which feeds 48v to the controller's "on" line.

Yep, you should be able to get 48v from your 3rd pack's + line. Check the balance of your cells if you decide to do this though. I'm not sure how much power it's using over the "on" line. Hopefully it shouldn't be much, but there's a chance this will drain packs 1, 2, and 3 more than pack 4.

 

[mistercrash]

Beautiful! Thank you. This will save my brake pads.

 

[jateureka]

How are you liking the BMS display and is the battery capacity gauge accurate?

I like the way you used the Nissan Leaf modules in the original sardine cans, looks like it made mounting them a bit easier.
I was lucky enough to receive 7 of these modules for my birthday to make a 14s2p add-on pack to extend the range of my Zero. I need to work out a suitable BMS but finding ones like yours with an LCD display that can handle the high current is difficult. I may have to resort to the more expensive individual modules and a CAN bus to a control module and display, like the ZEVA EVMS.

Doctor bass did modify a signal labs one for high current, but then their display is a little LED and no capacity meter. http://endless-sphere.com/forums/viewtopic.php?f=10&t=47812 You may be able to apply his technique for increasing the current rating of your BMS.

 

[inedible]

I've been meaning to update this thread for a while now, but haven't gotten around to it.

Long story short, I fried my BMS and my controller. Separate incidents.

The BMS got water damaged shortly after I installed it. I was too impatient to wait for the ACF-50 waterproofing stuff I ordered to arrive, but I wanted to test out my modifications so I took it for a spin around the block. I had taken the solder blobs off the shunts in my controller to lower the amperage, since it was tripping the 60A alarm. Took it for a spin around the block, snow got in, fried half the BMS when I brought it inside and the snow melted. Now it only sees 8S out of 16. Probably something very simple to fix, I suspect it may be a single diode, but I'm too frustrated to try and fix it and it's just sat there.

Anyway. It was good. It seemed like it made some sane SOC calculations, though I never got a chance to cycle it, so I don't know to what extent it "learns".

The LCD on this one was pretty enormous. Bigger than I was expecting. Like, four inches by three inches, which IMHO is way too big for a bike.

The 24S version of this BMS is capable of 200A at 100V, and its screen is a much smaller OLED that would look a lot nicer on a dashboard. I just got the 16S one because it's cheaper and I only have 16S of batteries anyway.

For my scooter, I was assuming 40A would be enough.. It turns out when going up big hills etc, I was drawing 50-60A, which is within the acceptable limits for the BMS, but above its continuous rating. If I wanted to go with more power I'd disconnect the main leads to the BMS, so it would no longer be able to cut power, but at least it'd monitor and balance the cells.

 

[Laserman]

Have you thought of using this controller http://kellycontroller.com/keb72301x24v-72v150a30kwe-bike-brushless-controller-regen-p-274.html
I am waiting for funds to build up before ordering one