How to wire a Lithium Battery Pack Q

In summary, a 200 watt x 6 hr @ 85% system efficiency lithium ion battery pack can provide up to 48 volts @ 29 amps of power to a 12 volt electronics system.
  • #1
hi all,
i am embarking on a new project, building a outdoor rolling credenza that has TV (with air operated TV lift), cd player, small receiver, 100% wireless (power and wifi, etc).

my design calls for a battery pack that can deliver approx 5x106 joules, this leaves me in the ballpark of 12v@115Ah, or 48v@29Ah
in general this is 200watt x 6hr @ 85% system efficiency.

true sine wave inverters run best at 48vdc, but a 12v inverter can also work.

(12v inverter) can i run 12v Lithium batteries in parallel if they are isolated via diodes and the charger has four independent cell chargers,
or, four 12v Lithium batteries in series for 48v (can a 4 cell charger straddle each cell in series and be ok?),
or do i source one 48v ~29Ah battery

any suggestions?
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  • #3
Spinnor said:
hah, i will need a short cord, but it will likely be mounted to the rolling cart via a wind-up mechanism, so that when not in use i can plug it into charge the batteries.

its a project, a completely wireless project, including wireless power, wifi, and Miracast. having a cord laying across my back patio as a tether is the old way, this is the new way. if it goes well, well, it might be my 2nd job fab'ing complete solutions like this, etc.
  • #5
i am looking for just the batts, and ideas about design. 4 12v in parallel vs 4 12v in series vs 1 48v
delivered energy has to be around 5x106joules, but i am not 100% sure if i need some headroom in there because the 200w inverter i am looking at does a shutdown at 10.5v or 42v (12v vs the 48v model, etc).

can i extract that much energy from a 48v ~29Ah batt, or four 12v ~29Ah batts w/o the batt voltage reaching shutdown threshold of inverter?

1. How do I determine the correct wire gauge for my lithium battery pack?

The correct wire gauge for a lithium battery pack depends on the pack's voltage and current rating. Generally, a higher voltage and current rating requires a thicker wire gauge to handle the increased power. It is important to consult the manufacturer's specifications for the battery pack and use a wire gauge that can safely handle the maximum voltage and current of the pack.

2. Can I use any type of wire to connect my lithium battery pack?

No, it is important to use wire that is specifically designed for use with lithium batteries. This type of wire is typically made with high-quality materials and has a high temperature rating to ensure safety and prevent damage to the battery pack. Using the wrong type of wire can lead to overheating and potentially cause a fire.

3. What is the best way to connect the wires to my lithium battery pack?

The best way to connect wires to a lithium battery pack is by soldering. This creates a secure and reliable connection between the wires and the battery terminals. It is important to use a high-quality soldering iron and to be careful not to overheat the battery pack during the soldering process.

4. Is it necessary to use a battery management system for my lithium battery pack?

Yes, it is highly recommended to use a battery management system (BMS) for a lithium battery pack. A BMS helps to monitor and balance the individual cells in the pack, preventing overcharging and over-discharging, which can lead to damage or failure of the battery pack. It also provides important safety features, such as overcurrent and overtemperature protection.

5. Can I replace the wires in my existing lithium battery pack?

Yes, it is possible to replace the wires in an existing lithium battery pack, but it should only be done by a trained professional. The process involves carefully removing the old wires and soldering new wires in their place. It is important to use the correct wire gauge and to ensure the new wires are securely connected to the battery terminals to avoid any potential hazards.

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