Onboard charger output.

Itsmcb

Itsmcb

Joined
Mar 30, 2019
Posts
2,943
Likes collected
5,699
Location
Cardiff, UK
Funster No
59,476
MH
Coachbuilt
Exp
Since 2016
How can I determine the output of my onboard charger? . I do have a multimeter 🙂
 
The multimeter will tell you the volts on your charger output. However, that tells you only so much (although this might be enough depending on why you are asking). To tell amps, you will need some sort of shunt (an accurate low resistance device in line with the battery) to measure the voltage across that. Your multimeter might have such a 10A device built it, but it would be hairy to use it safely and it is one of those "if you need to ask" type questions.
 
Itsmcb said:
How can I determine the output of my onboard charger? . I do have a multimeter 🙂
Click to expand...
Set the multimeter to volts DC and put the probes on the battery terminals. Sometimes the onboard charger is just a 13.8v power supply like our Elddis one was. To see what it's up to you've either got to watch it or get it's user manual.. Or Google it 👍
 
Lenny HB said:
The the make and model number and I'm sure one of us on here will find the info.
Click to expand...
It's in a 96 Kontiki 640. Built into the power supply unit in the wardrobe. No labels at all sadly. Everything is working fine, I am thinking of adding a second 110 amp leisure battery and was just curious how quickly (or slowly) it might charge them.

Subscribers  do not see these advertisements

 
It’s 10 amp at 13.8 volts. It will really struggle to keep on top of 2 x 110 amp batteries. Depending on. How much demand. Rule of thumb min unit capable of charging at 10% of capacity
 
Bessy765 said:
It’s 10 amp at 13.8 volts. It will really struggle to keep on top of 2 x 110 amp batteries. Depending on. How much demand. Rule of thumb min unit capable of charging at 10% of capacity
Click to expand...
If it is that type the Batteries will never get a full charge and will only last a couple of years. If you want your batteries to last you need to replace it with a decent multi stage cgarger.
 
Bessy765 said:
It’s 10 amp at 13.8 volts. It will really struggle to keep on top of 2 x 110 amp batteries. Depending on. How much demand. Rule of thumb min unit capable of charging at 10% of capacity
Click to expand...
I do have 270 watts of solar on the roof so during the summer I think the battery gets fully charged from that. I want to add a second battery to give more reserve through the winter. Can I add a second freestanding charger to use through the winter without disconnecting the existing one?
 
You would be better disconnecting the existing one as it is not doing your batteries any good.
If your current battery is much more than a year old you need to replace that as well when adding the second one.
 
if I recall correctly, there is a switch to turn the built in charger on/off. If you install an updated charger, remove the fuse for the built in one. Otherwise the new charger will see the constant 13.8v put out by the old one and assume the battery is fully charged

Subscribers  do not see these advertisements

 
I removed our old charger completely. It's left a nice slot in the top of the fuse box for the mini socket set and clamp meter 😎
 
Im in a similar boat. I am thinking of remmoving the old 10a charger in the sergant control panel and addingt he Victron30 amp multistage somewhere.
My question is if I find the exisiting output cables from the old 10a would the cables from that to the batteries which I am (upgrading to lithium 200a) be ok to take the new current.

Thanks
John
 
Last edited:
Tombola said:
Im in a similar boat. I am thinking of remmoving the od 10a charger in the sergant control panel and addingt he Victron30 amp multistage somewhere.
My question is if I find the exisiting output cables from the old 10a would the cables from that to the batteries which I am (upgrading to lithium 200a) be ok to take the new current.

Thanks
John
Click to expand...
Not in an Autotrail, cables are way under size for the existing install.
 
just mount the new charger nearer the batteries and run an over specced cable between them

Subscribers  do not see these advertisements

 
TheBig1 said:
if I recall correctly, there is a switch to turn the built in charger on/off. If you install an updated charger, remove the fuse for the built in one. Otherwise the new charger will see the constant 13.8v put out by the old one and assume the battery is fully charged
Click to expand...
Ah, yes there is a switch on the top of the box👍. I can just turn it off, then I would have a back up if the new charger failed for any reason.
 
I have a single 230v socket in the locker near my battery (ies). Can anyone recommend a suitable charger ?
 

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