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Battery Charger

Introduction

Our System

Solar Panels

Batteries

12v Battery Charger

120v AC Power Inverter

We've been camped in areas that are so sunny for the solar panels, that we haven't had to use our charger yet.

Many larger inverters include a built in charger. Our Prosine 1800 does not. We selected the TRUECHARGE 40 from the same company that makes the Prosine inverter.

Originally, I thought that an integrated inverter/charge would be better. I don't know how the integrated units function, however I like having the independent control of the charger. Since our solar panels are recharging the batteries daily I have the circuit breaker for the charger turned off.

I don't know the real specification of the charger/converter that that factory put in our trailer. I do know that this charger running for three hours a day with the generator was not enough to maintain the batteries. Several times I was told that these charger/converters may be rated for 50 amps, but due to inefficiencies deliver much less.

CHARGER OPERATION

The TRUECHARGE provides settings for:

Battery types of flooded, sealed gel (GEL), and absorbed glass mat (AGM) batteries.
Temperature setting
Charge modes of 2-stage, 3-stage, fixed 13.5 volts, and equalization.

The 3-stages of Charging.
Bulk, Absorption and Float.

During the bulk phase the charger provides the rated current until the battery approaches 14.4 volts. That's about 75% of the battery's charge. More than this would cause excessive gassing of the electrolyte.

The next phase, absorption, the voltage is held just below 14.4 volts by steadily decreasing the charge current until it current drops below 5 amps.

Then the float phase begins. It is a constant 13.5 volts to maintains the battery's charge without losing electrolyte through gassing.

Note: Since golf cart batteries are optimized for frequent charge/discharge cycles, I use the 2 stage Bulk/Absorption mode. Our solar panel charge controller provides similar functionality as well.

A special equalization mode, (for flooded batteries only,) is used every few months to overcharge your batteries. This reconditions the battery by creating rapid gassing that creates a stirring action to reverse electrolyte stratification and breaks up any build ups of lead sulfate on the plates. Contact the manufacturer for the correct equalization process and frequency for your batteries.

Three weeks in cloudy Seattle and still the solar panels were sufficient to maintain the batteries.