Would battery charge at low voltage input from the charger?

Hi everyone,

I have solar charger rated at 9volts 1A (I was able to obtain this measurement no problem), which is supposed to charge my 6volts battery. But I found out that the output voltage of my charge controller is 0.67volts and current is at 0.99mA but my battery is rated at 6v/4.5Ah. Would the low voltage output from my charge controller able to charge my battery?

I am greatly confused why is the charge controller output of 0.67volts only, I know there is something wrong with this but I don't know what.

Please assist me your help is highly appreciated.


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frollard5 years ago
Because the charge controller is controlling charge, and your multimeter doesn't look like a battery, so it cut off the charge voltage. Test it while the battery is connected and charging. While-ever the output is higher than the battery voltage, the battery will accept the charge.
mitchiko (author)  frollard5 years ago

But the measurement that I am getting with a multi tester is the same voltage when I measure the voltage of thebattery. Meaning the Open Circuit Voltage from the charge controller is equal to Voltage capacity of the battery.

[Voc (charge controller) = Battery voltage]

So do you think that the measurement I am getting is from the battery itself and not from the charge controller?

As to my little knowledge with Electricity, you should have a higher voltage to charge a battery otherwise you cannot charge the battery. Is it correct?
But as Frollard says, your meter isn't a battery - when the charger is connected, it sees very very little current flow, so says the battery is charged, and turns off.

Test the theory by connecting a resistor to the charger - 20 Ohms or so.
mitchiko (author)  steveastrouk5 years ago
So Steve,

Are you trying to tell me that I should connect the Charge controller to the battery then connect in parallel the multi tester? Is there any room for error for this as I am having to voltage source, battery and charge controller. When you say connect a resistor what do you mean by this? Connect a 20 ohm resistor to the charge controller in series then measure the voltage of from what point to what point
Since it is a charge controller it's designed to protect the panel and the battery from over/under voltage, etc. When it senses no battery connected, or battery full, it shuts off, hence no (or very little) voltage showing up.

Testing with the real battery and looking at the voltage over time you can see whether the battery is taking a charge.
Try the first option !
The meter will not affect the circuit

I meant to use the resistor "as a battery", as far as the charge controller is concerned.