Top 10 Things to Ask Your BESS Supplier

How much usable energy will this system generate?

 A number of factors go into determining the amount of energy you can actually use with any given system. It’s important to note that nominal energy is not the same as usable energy and usable will degrade over time. This means your usable energy at five years may be greatly reduced from the nominal rating used when you first purchase the unit.

Can I expand or add to this system easily in future?

Some BESS types are harder to add onto than others. Make sure your system is flexible enough to make additions easy in years to come.

Will this system provide enough energy during the times I’m using the most power?

Have your potential supplier look at your usage to ensure power will be available at the times when you need it most – day or night, in any weather condition.

Do you conduct a site assessment for each unique location?

A cookie-cutter approach will not work when it comes to BESS. You need a system that’s designed and engineered specifically to suit its location. As an example, the positioning of your system should consider air flow for cooling and whether direct sunlight can influence the system’s temperature.  Both scenarios, if incorrectly applied will reduce the life of your system.

What is the calendar life of the batteries?

One factor that determines your BESS’ longevity is the battery calendar life. Batteries start to ‘age’ as soon as they’re made and each has an expiry date whether it’s in use or sitting on a shelf. Temperature, overcharge, undercharge and non-use will all effect the life of your battery product.

How many cycles do my batteries have before end of life?

The other thing that determines a battery’s lifespan is the amount of cycles it can produce. A cycle is one complete discharge of a battery. So you might discharge to 45% and then recharge back to 100% and that would be one cycle. The manufacturer’s specification should tell you the total number of cycles before the end of life.

How much maintenance do I need to conduct on the BESS?

Wet batteries will need to be topped up on a regular basis while VLRA or lithium products don’t. Make sure you know how much ongoing maintenance you’ll need to put in before you buy.

Can we use nano-carbon deep cycle VRLA batteries in my BESS?

Yes, it’s a battery that can be discharged and recharged more times than a normal lead acid battery and is suitable for BESS applications.

How long will it take from engineering to completion?

For a custom system, the engineering and manufacturing process should take a maximum of six weeks, including the install on site.

What is the warranty period for the electronics and the batteries?

Usually the warranty term for the power electronics is shorter than the warranty for the batteries in the system. Ask your supplier what your options are for replacing the power electronics if they fail before the batteries.
If you’d like to know more about BESS and our revolutionary batteries that offer the longest possible life for your system, contact us at Century Yuasa.