Hi all I recently put the multi meter across the 12 volt charger on my 2 kva Honda generator to see if it produced enough voltage to charge my batteries in an emergency. To my surprise it showed 22 volt seems a bit high to me or will that drop when it comes under load. what do the people that know think ? Landy
Whenarewethere said
10:22 PM Jun 20, 2020
Measure in with a load.
You would be better running proper smart charger of it. If needed you would be able to run a much higher capacity charger.
Tony Bev said
11:31 PM Jun 20, 2020
I am not a techi, so only going from experience
Brother with same genset as you, was charging his batteries
With an el-cheapo clamp multimeter, at the battery it showed 13.6 volts, and 8 amps
Mike Harding said
02:28 AM Jun 21, 2020
Do not use the so-called 12V output from generators for battery charging unless it's an emergency.
I have put an oscilloscope on the 12V output from a few generators and in all cases it's been a half wave rectified sine wave peaking at around 18V to 24V unloaded. This voltage level will overcharge a 12V battery and, eventually, damage it. Most certainly do not use this output to power any 12V equipment.
landy said
05:48 PM Jun 21, 2020
Thank you all for your comments and as suggested I would only use it to charge a battery if I was stuck somewhere and would always prefer to use a 240 volt charger straight of the genny. Mike I wish you would talk English mate I can tell positive from negative or wire a relay but your way out of my depth here. "I have put an oscilloscope on the 12V output from a few generators and in all cases it's been a half wave rectified sine wave " Landy
Mike Harding said
06:01 PM Jun 21, 2020
landy wrote:
Mike I wish you would talk English mate I can tell positive from negative or wire a relay but your way out of my depth here.
Sorry Landy :)
We tend to assume others are familiar with things which are well known to us.
The generator DC output is a sort of AC electricity rather than the pure DC produced by a battery. For battery charging this doesn't matter as the battery will sort it all out but if you were to power, say, a 12V DC motor from this it would not work at all well.
To my surprise it showed 22 volt seems a bit high to me or will that drop when it comes under load. what do the people that know think ?
Landy
Measure in with a load.
You would be better running proper smart charger of it. If needed you would be able to run a much higher capacity charger.
I am not a techi, so only going from experience
Brother with same genset as you, was charging his batteries
With an el-cheapo clamp multimeter, at the battery it showed 13.6 volts, and 8 amps
Do not use the so-called 12V output from generators for battery charging unless it's an emergency.
I have put an oscilloscope on the 12V output from a few generators and in all cases it's been a half wave rectified sine wave peaking at around 18V to 24V unloaded. This voltage level will overcharge a 12V battery and, eventually, damage it. Most certainly do not use this output to power any 12V equipment.
prefer to use a 240 volt charger straight of the genny. Mike I wish you would talk English mate
Sorry Landy :)
We tend to assume others are familiar with things which are well known to us.
The generator DC output is a sort of AC electricity rather than the pure DC produced by a battery. For battery charging this doesn't matter as the battery will sort it all out but if you were to power, say, a 12V DC motor from this it would not work at all well.