How to choose a good backup battery

First things first, believe it or not there are no warranties on batteries even in the international market so this means that you are at the mercy of what the manufacturers, distributors, resellers, consultants tell you while hoping for the very best. Hope is a good thing but it is usually not enough especially when you are paying for a service.

In reality, many manufacturers provide a few spares or extras based on the quantity of batteries ordered. For example, a container load of batteries could have 2, 5 or 10 extra batteries. This means that any dishonest person or importer can pay for and import substandard batteries into the country and sell them to unsuspecting buyers knowing fully well that the batteries would pack up sooner rather than later. Someone can ask for a reduction in quality just to make more profit.

Basically, the strength of a battery is based on the thickness of the plates inside (read the positive and negative terminals) and if the battery is a rechargeable one then the rate of discharge or generally cycling will determine how long the battery will last as you recharge and discharge the battery.

This means that a battery that is in use will ultimately get weaker and weaker until it can no longer receive charge or hold charge let alone deliver any power to any load. So, it is possible to have 2 different batteries installed the same day with the same load with performances that are as different as anything you can imagine.

Is there a way to tell how long a deep cycle battery will last in service? Unfortunately no, regardless of what you see printed on the specs as basically all the tests these figures are based on were carried out in lab conditions most times at 25 degrees centigrade.

In most cases, references and past experiences from friends and colleagues help or you simply have to trust what the manufacturer, distributor, reseller or consultant is saying, that’s a tough one though. However, there is one area you must not allow yourself to be short changed – manufacturer defects. While this type of problem would most likely be pushed to the end user I strongly believe that such should not be allowed to stand because only the manufacturer or its agents should be held responsible for such problems otherwise it would be criminal as that would amount to end users paying for the manufacturer’s mistakes, errors and incompetence.

Serious battery dealers have good plans in place to handle issues like these. Serious alternative energy consultants equally have good working arrangements with battery dealers to ensure that customers are insulated from manufacturer defects related problems.

My advice is this – if a battery dealer, service provider or manufacturer refuses to commit on manufacturer defects related problems then run fast and look for those that understand the need to handle these issues the way they should be handled. They are out there, just look hard.

A parting shot on inverter backup batteries. Avoid trailer batteries (generally call automotive batteries) as they are not designed for deep cycling and based on this fact would pack up faster than any good deep cycle battery unless you don’t see any problem in replacing your batteries in a matter of months. Sealed maintenance free (SMF) batteries are not deep cycle batteries even though deep cycle batteries are usually sealed and are maintenance free.

Chew on the difference, very important. I have seen SMF batteries deployed as deep cycle batteries and before you know it the clients begin to wonder why their backup time just went from say 10 hours to 2 hours in just a matter of months.

Perhaps, the issue of getting good batteries is one area where the credibility of the seller or service provider determines the level of trust a prospective client will have in dealing with a completely unfamiliar terrain.

Always remember that when it comes to agreements that if it is not written down then it does not exists and that an agreement is only as good as the willingness of all parties to abide by the it.