DC Velocity - August 2009

equipment&applications

a battery monitoring device with a fluid level sensor.

Watering can be done manually—either by using a hose to fill the battery’s cells individually or by using a single-point watering system, which lets you hook the hose up to one connection. For those who prefer an automated solution, there are chargers that will water your battery automatically through that single-point watering system, says

Blake Dickinson, head of applications engineering for AeroVironment, which manufactures fast-charging systems.

2. Equalize your battery. When a battery discharges, a couple of things happen. First, lead dioxide turns into lead sulfate, which builds up on the battery’s plates. Although the charging process turns the sulfate back into dioxide, a normal charge is often not enough to get rid of all the sulfate that has built up, according to Dickinson. The sulfation can make it difficult to recharge the battery.

Second, over the course of a week, the electrolytes in the battery acid can separate out, with the heavy ones sinking to the bottom while the lighter ones rise to the top. If they’re left stratified like this, the battery will not run efficiently.

An equalization, or extended charge, will remove the sulfate from the plates and destratify electrolytes, says Dickinson. This extended charge also equalizes all of the cells in the battery, so that the slightly weaker cells are operating at the same strength as strong cells. Eliminating that strength gap helps prevent battery failure, he explains.

3. Consider an additive. Another way to get rid of sulfate is to use an additive. Pratt of Multi-Shifter recommends using Varix. Varix, which requires only a one-time application, flushes existing sulfate buildup off the plates and prevents additional sulfate from bonding to them. This process can lengthen the life of a new battery and improve the run time of an older one, according to Pratt. “We’ve had many instances where a battery that was only working for four hours was back to six to eight hours [after treat-ment],” he says.

4. Monitor the battery’s temperature. Make sure that your battery doesn’t run too hot. “If your operating temperature stays above 115 degrees on a daily basis and doesn’t drop below that point, you’re asking for trouble,” says Waseem Ahmad, vice president of engineering for battery manufacturer Hawker Powersource, an Enersys company.

You can determine a battery’s temperature by inserting a thermometer into the cell or by taking an external reading using a heat gun. Alternatively, you can purchase a monitoring device for each battery that will track temperature as well as state of charge, peak current charging and discharging, and ampere hours consumed, says Ache.