Which battery is right for you?
When deciding which batteries to use with your backup inverter, there are a few things to consider:
Below we will compare the different common battery types and their pros and cons (as well as an approximate cost). This will help to pick the right type of battery for your system.
- How much ventilation is available for the battery bank?
- How many power outages are expected each year?
- How long does the inverter need to power the critical circuits?
- Is occasional (annual) maintenance OK?
Below we will compare the different common battery types and their pros and cons (as well as an approximate cost). This will help to pick the right type of battery for your system.
Option 1: Flooded lead acid battery
Cost Effective |
Some Maintenance
|
Requires ventilation
This battery is the most common and most cost effective battery available for your backup inverter system. Flooded lead acid batteries do require annual maintenance to ensure adequate water levels in the battery. Also they require adequate ventilation because they produce hydrogen gas during re-charging. There are 2 subtypes of these batteries that are used:
- Deep cycle marine battery - This type of battery is somewhat of a hybrid between a true deep cycle battery and a traditional auto battery. The lead plates used are more substantial than an auto battery, but are not as substantial as a true deep cycle battery. This type of battery will typically provide a reliable 80-100 cycles before it will start to noticeably degrade and not provide as long of a backup time period. However if outages are rare and the load is not large, it can be a great economical choice.
- Deep cycle battery - This type of battery is what is typically used in golf carts. They have substantial lead plates and provide hundreds of cycles reliably. This battery type is more expensive than the hybrid deep cycle marine battery, however it does provide more charge cycles for your backup inverter system and is a good choice for higher capacity and more frequent outages.
Option 2: Sealed lead acid battery (AGM)
Maintenance-free |
Requires no ventilation
|
More Expensive
This battery is similar to the flooded lead acid battery except that it is sealed and does not require annual maintenance. Also sealed lead acid batteries produce a lot less hydrogen gas when re-charging making them ideal for installations with lower ventilation available. The trade-off is that sealed lead acid batteries are typically more expensive than flooded lead acid batteries.
Note: Automotive batteries are NOT recommended for use in with the backup inverter. These batteries are built to provide large amounts of current for brief amounts of time (for cranking) and do not cycle well. They will not have a long life if used in backup inverter applications.
Where can I purchase batteries?
You can buy lead acid batteries from the following sources:
- Your local auto parts store
- Other local specialty stores like Batteries Plus
- Many online retailers
- Your local golf cart dealer
- Big box stores like Costco, Sams Club, and Walmart
