Used Batteries

Used lead acid batteries, especially large two volt telephone type cells can sometimes be found for sale. While used solar modules and inverters are usually an acceptable risK, used batteries are a high risk proposition. Should you consider them? In our experience, it is difficult to know just how an older battery has been used. Has the previous user taken good care of the cells or have they been neglected7 Have they actually been load tested or just cleaned ud and recharged? Our recommendation is to get as much information as you can on the cells, and load test them, or ask the seller for a load test. Without this test your are really guessing as to the remaining life.

If you are considering telephone cells, realize that they are normally shallow cycle lead calcium grid construction, and should not be used in a system designed for deep cycle use.

Overcurrent Protection

Batteries have the potential to discharge incredible amounts of power over a very short period of time, melting conductors and possibly starting a fire.

This is why we spend so much time and energy on overcurrent protection. It is not so much the PV module that we need to protect against, but the batteries. PV modules are current limited which reduces the danger, yet modules and their conductors also require protection. The idea of a fuse or breaker is to include a "weak link" in each circuit which will open if the current exceeds that which the conductor can safely handle.

In a typical PV system, we deal with both AC and DC power. Standard components purchased at building supply stores are typically rated for AC use. These are fine for inverter output circuit protection.

DC overcurrent devices required between the battery, inverter, controller and modules are much more specialized. They are generally heavier duty and more costly.

Of primary importance is to place a current limiting fuse and disconnect on the mam battery conductor and assure that all components on the DC side are rated for DC use.

If you are installing your own system, please obtain a copy of the National Electric Code, work with your inspector and be safe. We offer and suggest the publication, "PV Power Systems and the N.E.C. Suggested Practices,11 free to anyone who is interested.

DIY Battery Repair

DIY Battery Repair

You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.

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