The last few days have been more about thinking hard about the next few decisions, and buying a few more of the remaining items.

The chassis is done, and the battery tray (temporary) is in place (no pics, sorry).  This led to the hard thinking of what battery do I want - exactly which ones and how will they be mounted.

I was originally going to put two old deep cycle batteries in and press an old scrappy lawnmower deck into service, but both of those choices seem to be a lot of work that would have to be completely redone at some point.  Besides, that old mower is really a piece of junk anyway.  With a pair of batteries, I could get one cutting done, then they need a recharge.  If I get too far from the house and run out of juice, I'd have to tow it back.

The final plan is to have batteries, an alternator, and an engine with electric start/kill switch/pressure lubrication.

It occurred to me that I can use smaller ( lighter, cheaper ) batteries if I run an alternator.  On average, if the batteries remain fully charged, or nearly so, I can run much longer with less worry.

If I'm going to make the drive system for an alternator, I really only want to do that once so why don't I get the final stuff now.

1) New Engine - a Briggs & Stratton 121S75-2119 new from a surplus house.  Full pressure lube with oil filter, 12V electric start, 3150 RPM, 190 CC OHV 8.75 torque.  This is roughly what used to be called a 6 HP on a higher end mulching self propelled machine, a beefy one.

2) 24 V alternator modified single wire with a bidirectional fan as in this application it will run CCW opposite what most cars run.  It was cheaper to order from Northstar Auto Electric in Macedon that buy it online.  It is a modified Delco (GM) 10SI frame, one of the most popular styles ever made.

Both of the above will be in first thing next week, right after the Holiday (New Year).

With an alternator, I can avoid spending extra on deep cycle batteries and just use regular auto starting batteries.  Deep cycles like to be nearly fully cycled where auto batteries do not.  I can find cheaper and smaller ones, saving weight and money at the same time.

Also, with an alternator, I can reinstall the motor brakes as they draw current 100% of the time when moving, a luxury I initially thought would be bad if running straight off battery.  Now, if something goes haywire on the hill, the mower won't roll away in a fault condition.  That is probably a nice feature...