Generator- Excuse the Newbie Question!

StitchUp

StitchUp

Joined
Mar 12, 2012
Posts
1,423
Likes collected
1,671
Location
Bridgend, South Wales
Funster No
20,125
MH
Coachbuilt
Exp
Just started!
We have a small generator, an IMPAX Inverter 8001 Generator that has outputs for 12v & 230v.
Never needed to use it before as the sun always shines on Motorhomefun members :) and I don't like to use a generator because of the noise factor! The generator has both standard 230v output socket and a 12v output - I'm guessing I should use the 'mains 230v' output to recharge the van as I would if on a site with power?

Is there any merit in using the 12v output to charge batteries?

Cheers
 
Sort by date Sort by votes
You've got it right.

I have a 12v and 240v outputs on my little Honda genny.
I use the 12v to charge a battery directly.
The 240v plugs into the van like an EHU.

The quickest way to put power into a battery is via the 12v.

Very rarely use either these days with my solar stuff on the roof.


JJ :cool:
 
Upvote 0
JJ said:
You've got it right.

I have a 12v and 240v outputs on my little Honda genny.
I use the 12v to charge a battery directly.
The 240v plugs into the van like an EHU.

The quickest way to put power into a battery is via the 12v.

Very rarely use either these days with my solar stuff on the roof.


JJ :cool:
Click to expand...
Do you connect the 12v output to the battery and the 230v to the van at the same time?
 
Upvote 0
StitchUp said:
Do you connect the 12v output to the battery and the 230v to the van at the same time?
Click to expand...
You risk overcharging the batteries if you connect them directly to the 12v output of the generator. You can certainly charge the batteries with a genny but to be safe you would need to monitor the charging voltage and current.

If you use the charger built into the MH by using 230v into the EHU then it will be much safer and better for the batteries as the charger, if it's a good one, will follow a correct charging profile, dropping the voltage as the batteries charge.

Subscribers  do not see these advertisements

 
Upvote 0
JJ said:
The quickest way to put power into a battery is via the 12v.




JJ :cool:
Click to expand...
I think it depends on the output of the generator. I would suggest in most cases the most efficient way would be to allow the charger to do its work. You would of course need to ensure the charger does not pull more power than the generator can supply.
 
Upvote 0
stewartwebr said:
I think it depends on the output of the generator. I would suggest in most cases the most efficient way would be to allow the charger to do its work. You would of course need to ensure the charger does not pull more power than the generator can supply.
Click to expand...
You might well be right... but in my case (Honda1kw) I can assure folk that it is quicker to charge the cab battery direct from the 12v output rather than go via the van's system... I know this because I have needed to do so in the middle of nowhere!

JJ :cool:
 
Upvote 0
DBK said:
You risk overcharging the batteries if you connect them directly to the 12v output of the generator. You can certainly charge the batteries with a genny but to be safe you would need to monitor the charging voltage and current.
Click to expand...
I must have got lucky over all these years I have charged batteries from my Honda 12volt output...

This is something I have actually done over and over again in real life...


JJ :cool:
 
Upvote 0
It probably has a constant 12v voltage output which isnt good enough for batteries.
They need 14.4v to begin charge then drop eventually to 13.6v when charged

Subscribers  do not see these advertisements

 
Upvote 0
pappajohn said:
It probably has a constant 12v voltage output which isnt good enough for batteries.
They need 14.4v to begin charge then drop eventually to 13.6v when charged
Click to expand...

Well, I'm confused...

My Honda genny charges a flat battery perfectly well allowing engines to start!

I'm not interested in how many volts or amps or watts are optimal for charging stuff... what I am interested in being able to get vehicle(s) with flat batteries going by charging them with my genny via the 12v output socket.

This isn't based on reading stuff on the Internet... this is based on what I have ACTUALLY DONE in the real world many, many times.


JJ :cool:
 
Upvote 0
JJ said:
Well, I'm confused...

My Honda genny charges a flat battery perfectly well allowing engines to start!

I'm not interested in how many volts or amps or watts are optimal for charging stuff... what I am interested in being able to get vehicle(s) with flat batteries going by charging them with my genny via the 12v output socket.

This isn't based on reading stuff on the Internet... this is based on what I have ACTUALLY DONE in the real world many, many times.


JJ :cool:
Click to expand...
I can only assume that your inbuilt van charger has a very low charge rate to the engine battery.
My Honda EU20 will only supply 8amps at 12v but the onboard charger can do up to 25amps on mains power to either the habitation or vehicle batteries so would be over 3 times quicker on mains feeding the onboard charger.
 
Upvote 0
JJ said:
The quickest way to put power into a battery is via the 12v.
Click to expand...

JJ said:
I can assure folk that it is quicker to charge the cab battery direct from the 12v output rather than go via the van's system
Click to expand...

It completely depends on the power of the charger in your van.

According to this site The 2KW honda generator outputs 12v at 12A.
If you have a 10Amp 240V charger in your van then the 12v output on the generator will be quicker.
However, if you have 15A 240V charger in your van then the 240v output on the generator will be quicker.

It is all down to how many amps you can get into the battery. There is no single right answer as it depends on the equipment you have on board.
 
Upvote 0
Generators should always be run at the same time as roof top aircon. Cools the van, charges the batteries and pays back neighbours with who play loud " music" or worse have door slamming competitions in the middle of the night.
 
Upvote 0
I don't know or care what amps my van charger puts out...

The one time I needed to charge a flat battery on my new (to me) motorhome (alternator belt broke) the van charger via EHU from the genny was too slow...

I used the 12volt output... no problem.

But PLEASE everybody... DON'T do what I do...

...do what all the experts with their knowledge of amps/volts/watts and B2B and Lithium batteries with BM setups do...

They are the ones who know the real stuff...

I just do things the way that work for me!



JJ :cool:

Subscribers  do not see these advertisements

 
Upvote 0
JJ said:
I don't know or care what amps my van charger puts out...

The one time I needed to charge a flat battery on my new (to me) motorhome (alternator belt broke) the van charger via EHU from the genny was too slow...

I used the 12volt output... no problem.

But PLEASE everybody... DON'T do what I do...

...do what all the experts with their knowledge of amps/volts/watts and B2B and Lithium batteries with BM setups do...

They are the ones who know the real stuff...

I just do things the way that work for me!



JJ :cool:
Click to expand...
:) :) :)
Thanks for the effort
:) :) :)
 
  • Funny
Reactions: JJ
Upvote 0
JJ said:
I must have got lucky over all these years I have charged batteries from my Honda 12volt output...

This is something I have actually done over and over again in real life...


JJ :cool:
Click to expand...
Not lucky at all, as I said you can certainly charge a battery from a generator, of course you can and it's probably no different to using a cheap mains charger which just chucks out a constant voltage. But modern chargers are a bit more clever though.
 
Upvote 0

Join us or log in to post a reply.

To join in you must be a member of MotorhomeFun

Join MotorhomeFun

Join us, it quick and easy!

Join us

Log in

Already a member? Log in here.

Latest journal entries

Back
Top