1928 vintage car and using a lifePO4 battery to run some items.

[Genedna]

Hi!!
I have a 1928 vintage car, and want to run a Stereo with AMP, and install some airhorns.
The car uses a 6V battery, so I bought a separate LIFEPO4 100AH, 12V battery to run these items.

The stereo amp needs 15A, and the airhorns are also 15A. The stereo unit, not sure yet (trying to find out)
The battery says it discharges as 100A, so does that mean it's sending 100A into things if I connect them directly?

How would I make it safe to attach these things directly to the battery? Via some sort of thing that gives it the right Amperage?

Please can someone help on the best way to connect these things to this battery? I assume not directly?

The car will have no way to recharge this battery, so I will just charge it at night before I need to use it the next day, like a mobile phone. Below are the specifications of the Lithium 12V 100AH battery:

NOMINAL VOLTAGE 12.8V
CAPACITY 100AH
MAX SERIES / PARALLEL CONFIG 4P OR 4P
NORMAL CHARGE VOLTAGE 14.6V
FLOAT VOLTAGE 14.0V
DISCHARGE CUTOFF VOLTAGE 10.0V
CHARGE TEMP 0-45°C (60°C max discharging)
DISCHARGE TEMP 0-45°C (60°C max discharging)
SELF-DISCHARGE Less than 3% per month
INITIAL IMPEDANCE 220mΩ
WEIGHT 13KG
MAX CHARGE CURRENT 50A
MAX DISCHARGE CURRENT 100A
PULSE CURRENT 200A (10 Seconds)

 

[telectrix]

the current drawn from the battery is dependent on the load/s. i.e. if your loads draw 35A altogether, that's what the battery will supply. a 100Ah battery will be flat after 100/35 = 2.8 hours. (that's totally flat. in reality it will give up before then). what facility are you planning on to charge the battery?

 

[Genedna]

the current drawn from the battery is dependent on the load/s. i.e. if your loads draw 35A altogether, that's what the battery will supply. a 100Ah battery will be flat after 100/35 = 2.8 hours. (that's totally flat. in reality it will give up before then). what facility are you planning on to charge the battery?

Right. Perfect. Odd thing was I connected the airhorns directly to the battery to test them, and they didn't play (but clicked and tried) and got me thinking maybe was getting too many amps pushed in. But, see it doesn't work that way. So, maybe they are just faulty.
The Amp draws 15A, stereo maybe 10A. So, yes, will only get two hours or so of use, not that much really. Unless I ditch the amp.
Thanks for your help.

 

[Mike Johnson]

Tap off from two of the batteries as its four cell you will get 6.4volts, you could then run them in parallel and get twice the capacity, you will need a balance charger with the facility to charge each cell individually and balance leads.