[sdiy] I’m Looking for a simple circuit that simulates this type of battery (12V 9AH)

[Gordonjcp]

On Sun, Jul 02, 2023 at 03:49:29PM -0400, Jean-Pierre Desrochers wrote:
> Hi list,
> 
>  
> 
> I have a battery charger circuit that I need to fix and do some tests on..
> 
> It is supplied from a 15VDC (22VDC actually) at 1.2amp and its job
> is to charge a 12VDC 9AH battery for a small CRATE TAXI TX-50D portable guitar amplifier.
> 
> Its battery is done with a very high ESR value.. No recharging possible.
> 
> Now before I go buy a new one I’m Looking  for a simple circuit that simulates this type of battery (12V 9AH)
> 
> And will be connected to the battery terminals of my charger..
> 
> Any clue what this circuit would look like ?

Why are you trying to simulate the battery? To test the charger? If it's a sealed lead acid battery it should be putting out about 14.4V, it won't need to be smoothed or regulated (real lead acid car battery chargers are just a transformer and a rectifier!), and it should output maybe an amp or so into a flat 9Ah battery, which will then charge overnight.

A suitable dummy load would be a big wirewound resistor, or some 12V bulbs - a car tail lamp bulb draws about half an amp and an indicator bulb (or, the "brake" section of a dual-filament brake/tail lamp bulb) about 2A.

Just change the battery, the charger will be fine.

-- 
Gordonjcp