Update 2020-04-10
Part way through integration with battery pack and BMS completed. Drop through mounting also finished.
Arrived
Janux Quattro 4.25" TB DD Hubs
Yep, I know that I’m using eLofty drives, but word on the street was that the 5 pin eLofty adapters would fit the TB DD hub pattern. In addition I’m leaning heavily toward the 6" Evolve tires and wanted to validate that Evolve tires fit on these hubs. After getting the parts in I’m happy to report success on both fronts.
M5 Hardware
Rather than going with standard #10 hardware for mounting the trucks, I decided to use M5 hardware instead. This should also allow me to replace the stainless bolts on the eBoosted enclosure with black bolts (which fits the board aesthetic better). Having common hardware between the trucks and the enclosure mounts simplifies the parts list slightly.
1/2" Heat shrink
This allows me to complete the positive lead on the battery pack by giving rigidity to the in-line fuse.
Kapton Tape
It ends up that the enclosure is just a bit too narrow in the middle to fit all the N.E.S.E. caps. As such, I’ll use Kapton tape to cover the remaining bolts of the enclosures to minimize the chance of short.
XT30 Pigtails
I wanted to connectorize the charge port and since the charge current is ~4A, XT30 will be sufficient for this.
New
New Button
The Neptune 15 is a very full featured BMS. As such, it has its own power button which is required for proper function (more on this below). The button which is included is small and flimsy, so I’ll need to order a new button (latching not momentary) that is capable of panel mount and install it next to the AntiSpark button at the front of the enclosure. This button will also need to include an in-line connector to maintain N.E.S.E. maintenance access.
Changed
Button Move
Looking at how packed the rear of the enclosure is getting, I decided to relocate the AntiSpark power button to the front of the enclosure. This will require extending the leads between the button and the PCB, for which I’m considering using a simple 3 Pin ATX fan extender cable. Also note that these leads will run across the top of the battery pack, which means they must include a connector between button and PCB in order to maintain the ability to easily service the N.E.S.E. modules.
Complete
BMS Battery Leads
Completed the rebuild of the positive pack lead using the in-line fuse. The picture below is the naked lead. The heat shrink covered lead can be seen farther down.
N.E.S.E. Bolt Coverage
The eBoosed enclosure is just a little too narrow at the middle to fit the N.E.S.E. pack with the bolt covers on. As such, I’ve used some Kapton tape to cover the bolts on the pack edges in order to minimize the chance of short.
30Q Binning, Fish Paper, and Installation
I binned all the 30Q cells, but there wasn’t a single one out of the 50 that was move than 10mV out of alignment. I added fish paper rings the positive end of each 30Q and dropped them all into place in the pack.
Here’s a shot of the pack with the lid securely fastened into place.
Charge Port Soldering
I had a heck of a time getting the solder cups to behave when soldering the charing port. Finally got XT30 pigtail on and heat shrink covered the leads at the charge port:
Next was adding the XT30 pigtail to the load/charge leads of the BMS:
Finally I attached the whole charge group together:
BMS Setup and Test
Next was testing the BMS. Interestingly, the power on test only requires connection of the balance leads but also requires the connection of the power button to the BMS (latching not momentary). I had not taken this into account to this point so I ordered a panel mount button to fulfill this function. After attaching the included power button I was able to test the BMS using the Android App:
Once in the app, I customized the BMS settings. Anything not on this list I did not change from default:
| Section | Setting | Value | Comment |
|---|---|---|---|
| Dashboard | Guard Bar Lowest | 38.4V | 3.2V / cell |
| Dashboard | Guard Bar Lowest Alert | 40V | 3.3V / cells |
| Dashboard | Guard Bar Highest Alert | 49.8V | 4.15V / cell |
| Dashboard | Guard Bar Highest | 50.4V | 4.2V / cell |
| Dashboard | Dashboard | Voltage | Displays Pack Voltage |
| Dashboard | Cell Bar Lowest Alert Zone | 3.2V | |
| Dashboard | Cell Bar Highest Alert Zone | 4.15V | |
| Device | Cell Number | 12 | 12s |
| Device | Battery Type | Li-ion | |
| Device | Cell Voltage High | 4.10 | Increase Cell Longevity |
| Device | Cell Voltage Low | 3.20 | Increase Cell Longevity |
| Device | Cell 0V Margin | 25mV | Threshold to prevent never-ending charing if calls cannot balance closer than this |
| Protection | Charge Current Limit | 6A | Adapter can only supply ~4A |
| Protection | Temperature Limit | 65C | Termistor will only be near cells, so temp threshold should be notably lower than 80C |
| Protection | FET Temperature Limit | 70C | Unlikely we’ll hit this in the current charge only configuration |
| Charge / Balance | Cell Balance Delta (mV) | 50 | How far apart P-groups get before balance charging kicks in |
| Charge / Balance | Stop Charging CV Current | 0.10 | Threshold to prevent never-ending charging if calls cannot balance closer than this |
Battery Pack Charging
After customizing all my BMS settings, I verified pack charging using the Android App
Drop Through Mount Test
Using the M5 hardware, I mounted the trucks to the board drop through. Will need to test for motor and wheel bite later.
Anyone used backing frames for drop through mounting before? Considering that the majority of the impact will be absorbed by the pneumatics, I’m leaning toward not using them.
What’s Next
- Finalizing foam placement in the enclosure
- Wire routing for the motor leads and sensor wires
- Testing wheel bite and purchasing tires
- Testing motor bite and (possibly) purchasing harder bushings
- VESC programming
- Remote Programming
- Bench testing of fully integrated system
Research
Nothing in addition to previous posts.