Battery protection options

[lg4929]

I have two old 14s 1kwh LIIO batteries that I want to connect in parallel. The batteries already have their own internal balancer, so I am not worried about individual cells. Also, since I am connecting the two packs in parallel, I suppose there is no need to balance them.
The packs don't have any kind of over/under voltage protection, current limit or temperature protection.

And here is my problem. I keep looking over different types of BMS products and all of them seem to have balancing features that require linking the individual cells. For example a 20s BMS has 20 wires to link to the cells, plus the two main terminal wires.
I only have access to the battery pack 48V +/- terminals (the cells are encapsulated in the pack).
In my case I need a simple BMS or some other device that has only two terminals. The BMS should support support 48V, ~150amps and at least the voltage and current protection.

First of all, since I don't have much experience with batteries, is this setup feasible? If it is, what kind of BMS or similar product could I use in my case.

 

[robbob2112]

Assuming you are running them in series with each other an active balancer is what you are after

 

[Steve_S]

1) The exact battery type is needed. There are many Lithium based batteries, each is unique and have their own requirements.
Make, Model (photo's of labels) etc are all helpful to know what you really have.
- Batteries in Parallel increase the stored AH but not voltage.
- Batteries in Series increase voltage but not stored capacity.

When connecting Battery Packs in Parallel to make a Battery Bank:
- you need to use Equal Length Battery Cables to a common bus which most people use BUSBARS for.
- Use the same wire gauge from Batts to Busbar, Busbar to Inverter system.
- Each Battery should be fused for it's max output capacity. IE a 100AH Battery capable of outputting 100A should be fused to 125A.
You can also use DC Breakers as an option.
- Use QUALITY Busbars and NOT those cheapo Chinese pair sets that sell for $40. BE CAREFUL !
- DO NOT SKIMP on Fuses or Breakers, some do and regret it !

Below is one of my simple diagrams for a "Component" based Solar Setup, this shows 12V but similar all the way up t 48V.

 

[lg4929]

Thanks for the replies. I attached picture of the battery.
Specs: 48v 14s 6p, ~1kwh. Each of the two packs them have their own balancer (according to the seller). From what I understand they are dismantled from old scooters.
So, for current protection I can use a DC fuse or breaker and pay attention to max instant amps. Sounds fair.
What about over/under voltage? What should I use for protection. I know that theoretically I could use the inverter for this purpose. But I want a second level of defense, supposing someone will miss configure the inverter, I want some other protection to kick and not allow over or under voltage.

 

[Steve_S]

Without knowing the precise chemistry (each have a different voltage curve) and the Amperage ratings the cells/pack can discharge & charge at, it's impossible to give you specs for fusing, voltage settings etc.