Sparrow >> Service >> Electrical >> Batteries

Intro

The Sparrow was built to accommodate "Optima Yellow-Top" batteries. The battery boxes are close to the exact dimensions of those batteries and it's difficult to replace them with anything but these batteries. "Optima Blue-Top" batteries are the same thing with extra posts for attaching additional loads. Blue-Tops fit, though they make the installation of battery regulators more difficult, as the extra posts take up space that's useful in regulator placement.

Optima batteries come in several sizes. The ones that fit are the "D34" model (Yellow-Top) or "D34M" model (Blue-Top). They're nominally 55Ah, though that's the twenty-hour rate, i.e. these batteries can put out 2.75A for 20 hours. We Sparrow owners are more interested in how much power these can put out in about a half hour. Typical Sparrow owners see about 20Ah of useful energy at this rate.

See http://www.optimabatteries.com for more information.

Charging with a 12 V charger

Use an isolated 12 V charger (most are).
Connect to the + and - leads of a single battery
Charge it fully
Go to the next battery
There's no need to disconnect the battery you're charging from the rest of the pack

Replacing the Battery Pack

    "Disclaimer: Others will have better approaches than this one.  Please revise, correct, or post alternate approaches here.  Photos and procedures in this approach work with Sparrow #218; if your VIN number differs substantially, some of these photos and procedures will not match yours."

Preparation: Park the Sparrow somewhere level, protected from moisture and theft. Take precautions against accidental electrocution or shorting:

Assemble the necessary tools. Here are those that I needed to remove all my batteries...
Figure out where you are going to stack all the old batteries. They are HEAVY and awkward. You will not want to be moving them around several times, and they quickly begin to crowd any average workspace. You will soon have 13 of them lying around! Decide where you want to take them beforehand, you will be glad to minimize the toting time.
Push in the Big Red Button (BRB).

Process:

Remove the Zivan battery charger from under the hood. Unplug it from the charge receptacle cord on the starboard side, unplug the grey +/- plug and the two little wires from the port side. (Photograph their arrangement first!)
Unbolt the bar restraining the upper battery. Remove its leads and cover them with duct tape. Label each with the number of the battery it was attached to: this will simplify the installation of the new batteries.