How can you tell a quality Lithium battery from a average lithium battery?
It is important to look for certain specifications to ensure that the lithium battery supports your application and will last the test of time.
Here are 6 key points to look for when choosing a lithium!
How to choose a quality Lithium battery
It is true that it is difficult to tell this by just looking at the battery itself, however, taking a moment to read over the specifications can save you not only big dollars but it can also save you a huge amount of headaches!
6 key points to consider when choosing a Lithium battery
1. The Brand name
Choosing a trusted and well known brand is one of the easiest methods to ensure a high quality battery is received. It takes years of good customer service and quality products to build a reputable brand, so usually good reviews and word of mouth can contribute to helping you selecting a high quality item.
2. The BMS rating
All reasonable Lithium batteries on the market are built internally with a BMS. The BMS is the 'Battery Management System' built within the battery itself and acts to control the input charge to the battery, the output capacity from the battery, heat operation and more.
The use of a BMS within a lithium battery is essential to ensure the battery will operate at its optimum, whilst offering a safe and reliable source of power.
But are all BMS systems built the same? The answer is no.
There are many differences with BMS systems and usually the size of the BMS board is one way to easily identify the difference between a high quality BMS system and an inferior model.
Take for example, our Thumper Lithium batteries in the image shown below. This particular image of the Thumper Lithium shows a 100 Amp BMS board. This is a high quality BMS board, designed to handle a continuous 100 Amp load with its 4 string design. This image then compares our BMS board to that of a cheaper brand Lithium battery (unnamed), which you can see is significantly smaller is design.
This unnamed brand claims that the this smaller BMS board is also 100 Amps.
3. The warranty period | Pro-rata vs Manufacturer warranty
Warranty on a Lithium battery can sometimes be a confusing and hazy topic. How is it that some brands are offering a whopping 7 year warranty whilst others with reputable names are only offering a 3 year warranty? ... well the difference is pro-rata vs manufacturing warranty.
But what does this mean?
Manufacturing warranty is a warranty given directly from the manufacturer of the product. It is a essentially a product guarantee that tells you as the consumer that your product is protected within that time frame for any defaults or imperfections that the battery may experience within normal operation use. This type of warranty covers either a repair or replacement of the item to have the item back to working condition.
Manufacturing warranty is the best type of warranty you would be looking for as it is essentially a product guarantee under normal use.
Pro-rata warranty is a warranty that many cheaper brands offer. This type of warranty is usually offered over an extended time (say 5 or 7 years). The warranty period looks appealing to the customer, however, it is actually designed to more so benefit the seller, rather than you as the end user.
The pro-rata type warranty takes the amount paid of the product and divides this amount over the total number of months within the warranty period. It then allows the supplier to calculate the remaining months in the warranty period and provide this amount back to the customer as a 'credit' to be used towards a replacement of a new battery... meaning you are actually spending MORE money to even have your warranty claim processed.
Example of Pro-rata:
Bob buys a Lithium battery for $ 500.00 with a 7 year pro-rata warranty period.
After 4 years and 2 months, Bob experiences difficulty with his battery charging and approaches the company about his warranty. The company calculates that Bob's pro-rata warranty period was 7 years (otherwise known as 84 months).
Bob has experienced 4 years and 2 months use from the battery (50 months), this means he has 34 months remaining on his pro-rata period.
The cost of the battery was $ 500.00 / 84 month warranty period = $ 5.95 p/mth
As Bob has 34 months of pro-rata warranty remaining, he is eligable for a credit of (34mths x $ 5.95p/mth = $202.30) towards purchasing of a another battery.
A pro-rata warranty will allow Bob to purchase another $ 500.00 battery with a credit of $ 202.30 to be applied to this, meaning Bob is now further out of pocket a value of $ 297.70 to claim his warranty.
4. The internal construction
This is a hard point to usually assess as most lithium brands do not like to show the internals of their lithium batteries. This may be for a number of reasons such as poor quality fastening of the cells, smaller cells than advertised, poorly manufactured BMS boards, or simply lack first hand use with the internals of the batteries.
Our brand of Thumper Lithium batteries use all high quality A grade cells, which are fastened together in a solid steel casing and secured with quality foam padding within a ABS case to ensure the battery has the highest strength possible when being used in rough terrains.
We are so confident in our battery that we have stripped one down to demonstrate the internals of the battery and how it is held together for you to see first hand.
Many cheaper lithium batteries on the market are only tapped together and do not use such a steel cage to secure the batteries and prevent movement.
5. Linking ability in Parallel and Series
Linking batteries to build a system capable of running heavy loads is common practice. But what good is it if your Lithium battery can not link more than 1-2 batteries?
Many cheaper Lithium batteries on the market will limit the number of batteries that may be linked in parallel and sometimes, it is limited at 2 batteries! This is because their BMS system inside of the battery can not support multiple batteries being linked together.
The Thumper Lithium batteries are non-limited on their parallel link up ability. This means you can link as many batteries together in a 12 Volt system as you desire!
6. The weight of the battery
Many cheaper brands of lithium batteries have been known to fill the battery with glass plates and old tiles in order to increase their weight to compensate for undersized cells.
A standard rule of thumb is a 100 AH battery should weight between 11 - 13 kg and a 120 AH should weight between 13 - 14kg and a 170 AH battery should weight between 15-16kg.
This can be used as an average guide as if you see a 100 AH battery weighing 10kg or less, then you can almost guarantee that it is not a true capacity battery.