A New Set of Batteries for the Elec-Trak

The battery pack on the Elec-Trak I bought had just about had it. It was good enough to drive the Elec-Track onto the trailer and off, but that's about all.

After some looking around I decided to buy a set of Trojan T105 golf cart batteries. These are commonly used in Elec-Traks and also in golf carts, and appear to be a high quality solution. This is an about $800 investment (more than I paid for the Elec-Track), so it bears some looking around to make sure you get a good set and take care of them.

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Installing the New Batteries and Cables

Since the old cables were in pretty bad shape, I decided to make new set of cables. I used solder terminals from DelCity. This worked fine, but its also not expensive to just get a set made. The folks who provide battery packs for golf carts or service golf carts are one good place to get the cables.

This shows the old batteries and cables. I marked the cables with numbers and took the picture to make it easier when wiring the new batteries. Basically, the 4 aft batteries in this picture are hooked in series with the two front compartment batteries to make a 36 volt pack. The small wire marked with a 6 and 7 are taps at 12 and 18 volts to power the lights and the winch.

This picture shows the new battery pack being installed in the new back battery box. The black material at the bottom is a layer of EPDM rubber roofing just to provide some extra protection from spills.

New batteries with rubber pan.

The new batteries installed with the new cables.

New batteries in the front compartment.

Wanting to treat my brand new batteries with caution, I tightened the battery terminal nuts with a torque wrench using the Trojan recommended torque value.

Note that spacers (as in thin sheets of plywood) will be required between the batteries and some of the battery compartment walls to prevent the battery case being damaged by things that project out from the compartment wall. Note where these are used when you take the old batteries out, and be sure to replace them when installing the new batteries.

Soldering the new cables.

Cut back the insulation for the terminal.

Clean the terminal and apply the liquid soldering
flux onto the wire.

I used these little solder slugs, but
wire solder works just as easily.
Heat the solder with a torch until melting,
then press the wire down into the
solder while still applying heat until
the solder flows into the wire strands.

Side the heat shrink tubing onto the wire and
terminal and heat until it shrinks down onto
the terminal.

A Caution on Elec-Trak Battery Packs

An "interesting" thing can happen in the Elec-Track back battery compartment: the driver seat sits on top of the hinged lid that covers the pack. A piece of plywood is used to separate the metal lid from the battery terminals. But, the plywood can wear down, and that coupled with the fact that the terminals on the commonly used golf cart batteries stick up a bit further than then original Elec-Trak batteries can make for a very exciting experience when the metal lid makes contact with the battery terminals. As Mark puts it, this can be catastrophic.

This is a picture of the lid (that the driver sits on) in the up position. The piece of plywood in the lid
is supposed to keep the metal lid from coming in contact with the battery terminals.

Having heard all sorts of stories about how easy it is to bring a good new set of batteries to an early death by mistreating them, I've started a battery notebook that keeps a record of charges, electrolyte levels, and cell voltages -- I'm trying to be a good parent to my little pack :)

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Gary

December 4, 2011