This is our project to recondition an E15 Elec-Trak electric
tractor. The aim is to get the Elec-Trak into good
enough shape for lawn mowing and snow throwing tasks as well as
(hopefully) to integrate the tractor with our existing grid-tied PV
system so that we can use the Elec-Trak for power during emergencies and
keep it charged with our PV array.
The Elec-Trak dressed for the snow
This has been a fascinating project and I can highly recommend it.
One thing I want to make clear is that I'm no expert on Elec-Traks or
on restoring them. If any of you old hand Elec-Trak folks see any
oversights or dumb mistakes, please let me know.
I'd especially like to thank Mark
Frerking who not only wrote the article
below for Build-It-Solar on the Elec-Track, but also found the Elec-Track that I
ended up buying, and has also been a great source of information on rebuild -- Thank you
Mark!!
I bought the E15 used from Joe in Colorado Springs and hauled it all the way
up to Bozeman in a small trailer behind our Honda Pilot. I'd like to thank Joe
and son for being patient and very helpful through working out the pick up logistics, the loading,
and passing on a lot of useful information about this E15.
What's an Elec-Track?
In a nutshell, the Elec-Trak tractor was a GE product in the 70's. The
Elec-Traks were a series of electric tractors and riding mowers that use an onboard bank of lead
acid batteries to power the tractor and also to power a large array of
accessories that GE offered. There were something of the order of 30,000
of these tractors made by GE and the companies that GE sold the operation to.
The machines are very functional and very durable. The Elec-Trak has
developed a devoted set of followers and there are probably thousands of them
running and being restored -- this is pretty impressive given that the last new
one left the factory in early 80's. There is also an active Elec-Track online owners club and a couple of good places to get parts from.
If you are interested in learning more about the Elec-Track, here are a few
good sources of info:
I particularly like George's site -- he has an incredible collection of
beautifully restored Elec-Traks. There is also a lot of very
good Elec Trak reference material on the site, including many of the original
manuals. Note also the solar electric array on the Elec-Trak barn roof!
Mark's beautifully restored E20
One of George's many restored Elec Traks
Goals for our Elec-Trak Project
The three main goals I have for the project are:
1 - Mow the Lawn and Blow the Snow
The immediate aim is to get the tractor back into condition to mow our much
too large lawn (about an acre), and also to do some of the snow plowing chores in
the winter. The tractor came with a mower deck, a front mount blade, and a
42 inch snow blower as attachments. Until recently, the tractor was being
used, so I'm starting from a pretty good base.
When I got the Elec Trak, the battery pack had about had it, and there is quite a bit of rust
to clean up, and a few things to fix. But, I had the advantage of starting
with an Elec Trak that had until recently been used.
Here are the details on putting a bit more life in my E15:
One reason we would like to move to a solar electric mowing and snow blowing
solution is that gasoline powered mowers are surprisingly heavy polluters.
They do not have catalytic converters and their emissions of unburned
hydrocarbons, oxides of nitrogen, particulate matter, and carbon monoxide are
quite high. So, switching to solar electricity for mowing and
plowing has more of an impact on air pollution than you might think.
The pollution estimates vary, and will be coming down some as new EPA
regulations go into effect, but any way you slice it, mowers are a large source
of pollution.
2 - The New Charger/Inverter (and Solar Charging the Elec-Trak)
My initial goal was to have a dedicated solar array and charge controller to
charge the Elec-Trak batteries. This seemed like a nice clean solution,
but the more I thought about it, the more it appeared to make more sense to just
charge the Elec-Trak from grid power and to expand my existing grid tied PV
array to cover the extra Elec-Trak energy usage. This way the PV panels
can be active all the time, instead of dedicating PV panels to the Elec-Trak
that would only be used a small part of the time. We have been planning to
expand the PV array anyway, so this just makes the expansion a bit larger.
The charger/inverter charging the Elec-Track from 120VAC.
The same charger/inverter mounted to the Elec-Trak
and providing 120VAC out in the field.
So, to charge the Elec-Trak battery pack, what I did (instead of a
solar charging setup) was to buy a combination charger and inverter
from Tripplite. The charger part of this heavy duty unit will charge the 36 volt Elec-Track battery pack
from a 120VAC outlet. Or,
out in the field, the inverter part will provide 120 VAC for tools etc from the battery pack.
It will also provide some power for the house in power outages (see below).
Normally, the charger/inverter lives in the garage next to the Elec-Trak
parking spot, and charges the Elec-Trak after use using a disconnectable cable.
When power is needed out in the field, the charger/inverter mounts to the back
of the Elec-Track (as in the right picture) and comes along to provide 120VAC
from the battery pack.
This worked out particularly well in that the charger that comes with the
Elec-Trak was missing on mine.
3 - Integrate With Current Grid-Tied PV System for Emergency Power
We currently have a
grid-tied PV system that works well and that helps us offset some of our
electricity consumption. But, as with all grid-tied systems that do not
have battery backup, when the grid power goes down, our grid-tied PV system also
goes down -- so, no power from PV in power outages.
My aim for an extended power outage is to use the Elec-Trak battery
pack with the new Tripplite charger/inverter to supply power to the house,
To recharge the Elec-Trak battery pack, I am using am reconnecting some of
the PV modules in our grid tied system to feed a regular PV system charge
controller to charge the Elec-Trak battery pack during the day.
After the power outage, the PV modules are restored to the normal grid-tied
configuraiton.
The battery pack will supply about 5 KWH of usable stored energy, and this
is enough to supply a few key loads via extension cords for an extended
power outage. The loads include fridge, a few efficient lights, the furnace,
and a few other odds and ends like a laptop and small TV. To
charge the Elec Track battery pack, six of the PV panels in our existing grid tied PV array
are reconnected to feed an Xantrex MPPT charge
controller. This provides enough power to fully recharge the Elec Trak
pack on a sunny day, and to provide a good charge even on a not so sunny day.
Back when we put in the original PV system, I thought about putting in a
grid-tied with battery backup, but the added cost of the fancier inverter and a
battery pack plus the long term cost of maintaining and replacing a battery pack
just seemed not to be worth it. This is especially true given that our
power is reliable, and the battery pack would just be sitting there doing
nothing 99.9% of the time. Putting the Elec-Trak battery pack into
service for backup power is really appealing to me in that its a battery pack
that is already earning its keep with lawn chores, and this is a chance to let
it take on another job without adding more battery pack expense and maintenance.
