Tuesday, June 29, 2010


There are various types of storage batteries on the market today which are used for solar applications. The most common are the lead acid batteries and sealed lead acid batteries. As technology advances toward producing electric vehicles we will be seeing the prices of lithium batteries becoming more accessible to the average user. But until then, most of us will still be mainly using the lead acid batteries. And it is these lead acid batteries I want to address in this post.

Batteries are the backbone to any Off-Grid or Grid-Interactive Solar Installation. They give the life to our alternative electric systems. Batteries like these also get our vehicles started, they are called Cranking Batteries. Cranking Batteries are rated by cranking amps where as Solar Storage Batteries are rated by their amp hour capacity. So whats the difference, an amp is an amp, no?

No, a cranking amp is what your battery can muster up for a rather short period of time. In other words when you crank over your engine it usually happens within a minute, if your vehicle is older it may take several attempts to get it started. And if your vehicle really wants to be difficult you may have to keep cranking it for a longer period of time and as you do, you will notice the battery get weaker and weaker. This is because you are using up its cranking amps. Cranking Batteries are meant to get the vehicle started and then it goes into charge mode while everything in your vehicle or boat runs off the charging alternator.

A Solar Storage Battery stores the amps produced by your generating system (solar modules, wind turbines, micro-hydro turbines, or a fossil fuel generator) up to the amount the battery is rated for. So now you can use those amps to create electric long after the generating source has shut down.

For the most part, you will put a major part of your solar budget into the purchasing if batteries. Because you will want the most amp hours you can afford, your batteries will be either 6 volts or less. This is because the more amp hours your battery puts out, the more lead it will contain, thus making them very heavy. All Lead Acid Batteries are made up of two volt cells such as the two volt battery shown above. A six volt battery is made up of three of two volt cells. When these cells are put together in a neat plastic container, they are referred to as a battery. So when you get into batteries with a thousand or so amp hours, just one cell could weigh a couple of hundred pounds and if you have a forty eight volt system you really want to deal with only batteries that are packaged as one cell.

Okay, enough about types of batteries, this story is more about the importance of battery maintenance.

Why is maintenance important? First of all you have a small fortune invested in batteries so you want to protect that investment. So the most important thing you can do is to think safety when being around your batteries. Keep all flames and sparks out of your battery room!

Always, always, always wear goggles, rubber gloves, an old long sleeve shirt and slacks (this will save alot of ruined clothing) that are just for working with your batteries.
  1. Keep your batteries out of your house
  2. Provide a separate space for them or put them in a Battery Enclosure.
  3. Where ever you put your batteries make sure that they are well ventilated.
Here are some of my recommendations and you should get into a habit of doing this at least once a month...
  1. Again keep all lit lames away from your batteries!!! I'll give you two incidents I am aware of why this is extremely important before I close this blog.
  2. Make sure that all your battery terminals are tightened down. Check this every time you do a battery inspection. Loose terminals can produce sparking which can lead to fires and worst.
  3. The next most important thing you can do is to keep your battery terminals clean. This can be done with carefully using a mild solution of water mixed with a small amount of baking soda (DO NOT ALLOW ANY OF THE BAKING SODA SOLUTION TO GET INSIDE THE BATTERY!!! If you do, you can kiss your battery good-bye.) and scrubing with a copper wire brush. Once the battery is cleaned use a product like Quik-Kote to coat all your battery terminals. This is an acid neutralizing product which will protect the terminals from getting corroded.
  4. Alway check to make sure your battery liquid levels full (use only distilled water). Low battery water levels help cause sulfation to build up on the batteries lead plates which reduces your batteries ability to hold as many amp hours as it could. There are Battery Desulfator which can help keep your battery's lead plates clean. There is also these little Water Misers, a product which a number of my customers seem to be happy with, which helps retard the rate at which your battery evaporates its liquids.
  5. It is important to monitor your battery's acid specific gravity levels as well. This is done with a hydrometer which is placed in the battery's cell opening. The hydrometer has a bulb which you genitally squeeze once its tip is in the acid. Do this about three times and then take your reading. If your readings are in the red, you are reaching the point where your battery's usefulness is about over. I have seen where using a Battery Desulfator has prolonged having to replace the batteries.
  6. A key to longer battery life is that when initially installing or when you replace your batteries, always buy your Batteries at one time. In other words don't buy some of them now and then say a year later buy some more. This is a good way to decrease the amp hour levels of the newer batteries.
Actually if you want to get more life out of your cranking batteries follow the above first four check points with them as well.

Lastly I want to share with you the importance of why fire and lead acid batteries do not mix. Recently, well in the last few months anyway the woman that works at our local grocery store had a scare. It seems that her husband walked into the dark room where their battery banks were and being that it was dark, he lite his cigarette lighter. And boom!!! The wife who was doing the dishes heard the explosion and ran to his aid. Fortunately the batteries were at the far end of the large room and that she had the good sense to pour water all over him. I say fortunately because if the batteries were near him he would be dead and if she had not poured the water on him, he would be permanently scared and blind. Not a good thing for an author and artist or for anyone for that matter. So be safe.

The second incidence I am aware of happened off Marina del Rey in California. I had been jogging on a coastal path just after sunset, the sky was getting dark when off shore there came a tremendous explosion. I turned just in time to see a ball of flame rising a good 100 feet into the air followed by a column of fire. A yacht anchored off shore had blown up. The next day I learned that the batteries had a loose connection and when the late owner attempted to start the engines, the batteries exploded. There were no survivors.

I would just like to mention one other fact for all you boat owners, and that is the boat also was carrying propane which helped make the explosion so massive. Propane is heavier then air so if there is a leak it therefore seeks the lowest point on the boat. And that is usually the engine room. So if you are going to carry propane I would suggest keeping it on deck near one of the side gunnals so that should it leak it drops toward the sea and not the engine room.

So my friends, be safe and check your batteries health at least once a month.

Terry R. Wolff