Thursday, February 11, 2016

Batteries Are In and Baby Got Bling (just some new shoes).

We kept it simple and put a single string of ten modules in the tray for, 120 V nominal and 15.6 kWh of capacity.

There's a couple of awkward-looking long jumpers in there, but it was the only layout that placed most positive and most negative at the back of the pack without placing any modules on edge.  
The rearmost compartment has one battery in it in this photo as a counterweight, but that cavity will remain empty for Phase 1.  It may be used when a second string of modules is added.  This shot was taken while filling the gaps with foam insulation board.  

After cabling up the battery pack, freshening up the Anderson disconnects and re-mounting them with stainless hardware (yes, the corrosion risk is tiny compared to the old flooded pack, but I don't like rust!), we turned our attention to the outside.  

Through creative dealmaking, I wound up with a couple of parts cars: a 1985 Nissan Pulsar converted by Dave Cloud in 1996, which the last owner had never gotten around to modernizing, so we're reusing the Valence battery pack that never got installed, along with the battery charger and a few other components to reuse on this project, and the motor, etc. for others.  

That car also came with some very shiny aluminum wheels that were good as new and period-appropriate for the Grumman.  Besides- everybody knows that little Japanese cars use a 4x100 lug bolt pattern, right?  Confident in that fact, I mounted new LRR tires and brought my prize to the student mechanics.    
Time for another lesson.  The Pulsar had 4x4.5" lug spacing, aka 4x113.4mm.  So no fit.  There's room in the solid centers to re-drill the 4x100 pattern, but machine shops willing to take on that work are rare, and I found a set of billet adaptors for less than redrilling should cost.  
The adaptors add 1" of track to each side, but the front tires still fit within the wheelwells and there's no chance of rubbing, even at full suspension travel.  In the rear, the sidewall bulge is barely wider than the body, but there won't be any rubbing either, due to the generous wheel openings.  All the tread is inside the wheelwell, but some fender flares might be in order down the line.  I'm not worried about extra stress on the spindles from a wider stance, as this battery pack is 484 pounds lighter than the original one, and even adding a second string will be 40 lbs less than original, and more evenly distributed.  Lastly this van was designed to carry a full load of mail in addition to the lead-acid batteries, so there will be durability to spare.  

Lastly these new wheels brought our attention to a bit of camber, probably because the suspension is riding higher to the tune of 484 lbs.  It's not bad, so I'll wait for the weight of a second string before adjusting the ride height.  And of course, if this project wraps up well, the kids would love to airbag Sylvester!