one 48v or 4 x 12v lithium?

[Rockten]

Hi Guys,

What are the advantages and disasvantages of having a single luthium battery of of 48V versus multiple batteries forming 48v?

The above question relates primarily to the golf cart but in your advice can also let me know what is best to buy if I also plan to use them for solar panels when I am not using the golf cart

Thanks for all the answers

[Volt_Ampere]

Advantage of one 48V is that the BMS works on all of the cells together to keep them balanced.

[Pat911]

Definitely want a single battery. As Volt_Ampare already stated, a single battery will have a single BMS protecting and balancing all the cells together. Four 12v batteries will have four BMS’s and the cells can only be balanced with the other cells in that battery, not the whole pack. You WILL end up in the situation where one battery will be limiting the maximum charge and discharge voltages of the whole pack.

It is best practice to have all lithium cells in a pack to be controlled by a single BMS.

Cheers
Pat.

[Andre Pappas]

I run an Eco Battery 48V 105Ah, they do identical cell matching as well in their batteries because Lithium is only as good as its lowest cell. I would recommend their battery and kit.

[klubber]

Originally Posted by Andre Pappas

I run an Eco Battery 48V 105Ah, they do identical cell matching as well in their batteries because Lithium is only as good as its lowest cell. I would recommend their battery and kit.

Little pricy and does that come with charger? There are many options with similar specs that are a lot less expensive

[Rockten]

Thanks for your valuable advices!

[rabbitreborn]

Having installed a bunch of setups using 4 12v lithium batteries and dealt with all the issues that entails I recommend a single 48v battery. Or possibly multiple 48v batteries hooked in parallel.......

[Rockten]

Thanks rabbitreborn! I am glad I asked this question. On youtube I saw alot of lithium conversions where more than one battery is installed by people who should know as if it does not matter..

[Pat911]

Hi Rockten,

It’s a good thing that you asked the question before forking out for a lithium battery upgrade. There is misinformation not only on YouTube, there are also suppliers that will happily recommend and sell you 12v lithium batteries for connection in series for a higher voltage or for many other inappropriate uses. It highlights the ignorance when it comes to lithium battery technology.

The following is off topic but needs to be explained so that people are made aware that lithium batteries cannot be substituted for lead acid in all situations.

It is widely assumed that because a lithium battery is advertised as 12v, it can be used in place of FLA or AGM batteries. This is okay in some applications, but certainly not all. In many situations you won’t be getting the most out of the battery, such as series connected, and in other situations it is downright dangerous, such as an automotive starter battery.

Disregarding the incorrect charging algorithm, in automotive starter applications, you WILL end up in the situation where the battery becomes fully charged and the BMS will disconnect the battery. You now have an alternator running without a battery connected. Any auto electrician can tell you that without a battery connected, the alternator output voltage will rise to dangerous levels, damaging the vehicles electronics, computers etc. Alternatively, if the battery is in a discharged state, it will draw huge currents from the alternator, possibly damaging it in the process. Either way, a very expensive exercise.

You should make sure that you are well informed before replacing a lead acid battery with lithium, and when you do, make sure you purchase a lithium battery that is appropriate for the task.

Cheers
Pat.

[simicrintz]

Youtube is a double edged sword-when the info is good it is a blessing, and not so much when you get wrong info!

I could not have done my conversion without this page, Rockten. Listen to what folks like Pat911 and Volt_Ampere (and others much smarter than me!) have to say and you will do just fine!