split charging system for Viano 2011 3.0V6

[pugsley]

Can anybody give me advice on fitting a split charging system on my Viano 2011 V6? I need to power an oxygen machine and possibly an xbox for the kids. I am not looking to run something whilst stationary, just when the engine is running. One Auto Electrician has told me that some mercedes will not run one, something about the alternator, is this true?

 

[Larkone]

Friend asked the same recently for a VW and I found this for him

Split Charging Guide - caravans, campervans, motorhomes, boats, vehicles

Our guide to split charging for caravans, campervans, motorhomes, boats & commercial vehicles. A look at how it works & the various technologies available.

www.12voltplanet.co.uk

 

[pugsley]

Friend asked the same recently for a VW and I found this for him

Split Charging Guide - caravans, campervans, motorhomes, boats, vehicles

Our guide to split charging for caravans, campervans, motorhomes, boats & commercial vehicles. A look at how it works & the various technologies available.

www.12voltplanet.co.uk

Many thanks for the info, I am still a bit lost, I will wait for the experts, but I now have some knowledge.

 

[M80]

A split load charging system is to run 2 batteries. So that when stationary you only drain down the leisure battery, and leave the start battery so that it can start the engine later.
When running again you would switch over to the leisure battery to recharge it for the next stationary discharging.

It seems to me that if the total load of the Viano
plus the additional loads of your other kit,
is within the 180 amps capability of the alternator,
then there is no need for an additional battery.
Actually I don't see it would serve any advantage anyway.

If your total load is greater than the alternator capability then you would need a greater output alternator. Or you would be running any / all batteries down as you drive.

I would guess on an Xbox load being around 15amps max?? Assuming you run it from a ciggy socket that's the limit anyway.
What is the rating of the oxygen machine, as that seems to be of relevance? If it is greater than 15amps you would need to run a dedicated supply.

Ignoring starter loads (and even heated seats and electric door loads might be treated as not overly relevant as they are short duration loads) the main fuse protecting the fuse / relay board is 60 amps.
It's a simplistic view but that leaves 120 amps available.
Taking a nominal voltage of 13.2 volts, that leaves nearly 800 watts of available power.

 

[pugsley]

A split load charging system is to run 2 batteries. So that when stationary you only drain down the leisure battery, and leave the start battery so that it can start the engine later.
When running again you would switch over to the leisure battery to recharge it for the next stationary discharging.

It seems to me that if the total load of the Viano
plus the additional loads of your other kit,
is within the 180 amps capability of the alternator,
then there is no need for an additional battery.
Actually I don't see it would serve any advantage anyway.

If your total load is greater than the alternator capability then you would need a greater output alternator. Or you would be running any / all batteries down as you drive.

I would guess on an Xbox load being around 15amps max?? Assuming you run it from a ciggy socket that's the limit anyway.
What is the rating of the oxygen machine, as that seems to be of relevance. If it is greater than 15amps you would need to run a dedicated supply.

Ignoring starter loads (and even heated seats and electric door loads might be treated as not overly relevant as they are short duration loads) the main fuse protecting the fuse / relay board is 60 amps.
It's a simplistic view but that leaves 120 amps available.
Taking a nominal voltage of 13.2 volts, that leaves nearly 800 watts of available power.

The only information I can see on the Oxygen Machine says it is 380w, I will have to ask my supplier about it. I would still need an inverter though, right?

 

[pugsley]

The only information I can see on the Oxygen Machine says it is 380w, I will have to ask my supplier about it. I would still need an inverter though, right?

It runs off a 13amp 3 pin plug and is 300 watts running

 

[M80]

You'll need an inverter.
An issue here is the inverter may need to be around twice the stated rated max, as they tend to suffer volt drop as load increases.
If the oxygen machine has a high starting current there is another issue.

Let's assume we are designing for the 300 watts,
then still using the 13.2 volts, you will need a supply of around 23 amps.

It would be ideal if you were able to borrow an invertor, to see how it behaves when trying to feed the oxygen machine.

For me i would like to see if the (300 watt) invertor can start the machine.
If so I would then measure the current at load.

I view that the alternator can handle this, but others may not agree that it can handle it as a constant load.
Is it envisaged as constant, or sporadic?

 

[Doug1234]

I looked into fitting a split charging relay into my om642 engined jeep but it was not possible as the alternator is on a Lin bus and controlled by the ecu. The link Larkone posted mentions ‘smart alternator ‘ but does not go into mentioning Lin bus control but basically that’s what a smart alternator is..

IMPORTANT: If you have a vehicle with a 'smart' alternator (as a rule of thumb this applies to vehicles with Euro 5 or 6 compliant engines onwards) the split charging methods outlined above won't be suitable and you'll need to use a Battery-To-Battery charger instead. Find out more info by reading our Knowledge Centre article and discover the benefits of using a battery-to-battery charger over split charge

 

[pugsley]

You'll need an inverter.
An issue here is the inverter may need to be around twice the stated rated max, as they tend to suffer volt drop as load increases.
If the oxygen machine has a high starting current there is another issue.

Let's assume we are designing for the 300 watts,
then still using the 13.2 volts, you will need a supply of around 23 amps.

It would be ideal if you were able to borrow an invertor, to see how it behaves when trying to feed the oxygen machine.

For me i would like to see if the (300 watt) invertor can start the machine.
If so I would then measure the current at load.

I view that the alternator can handle this, but others may not agree that it can handle it as a constant load.
Is it envisaged as constant, or sporadic?

It would need to constant, whilst driving, I wish I lived closer to Derby! I do have an offer of an inverter from my Van Man, I may just pop over and get it, got to be worth a try.

I looked into fitting a split charging relay into my om642 engined jeep but it was not possible as the alternator is on a Lin bus and controlled by the ecu. The link Larkone posted mentions ‘smart alternator ‘ but does not go into mentioning Lin bus control but basically that’s what a smart alternator is..

IMPORTANT: If you have a vehicle with a 'smart' alternator (as a rule of thumb this applies to vehicles with Euro 5 or 6 compliant engines onwards) the split charging methods outlined above won't be suitable and you'll need to use a Battery-To-Battery charger instead. Find out more info by reading our Knowledge Centre article and discover the benefits of using a battery-to-battery charger over split charge

Thanks Doug, that could be what the Auto Electrician man is talking about, I was just a bit concerned that he may have been pulling the wool over my eyes.

 

[pugsley]

You'll need an inverter.
An issue here is the inverter may need to be around twice the stated rated max, as they tend to suffer volt drop as load increases.
If the oxygen machine has a high starting current there is another issue.

Let's assume we are designing for the 300 watts,
then still using the 13.2 volts, you will need a supply of around 23 amps.

It would be ideal if you were able to borrow an invertor, to see how it behaves when trying to feed the oxygen machine.

For me i would like to see if the (300 watt) invertor can start the machine.
If so I would then measure the current at load.

I view that the alternator can handle this, but others may not agree that it can handle it as a constant load.
Is it envisaged as constant, or sporadic?

Tested an inverter on a battery today and it handled the oxygen machine without a problem! Next to try it on the Viano, with luck it should work without the need for a leisure battery set up, happy days. Many thanks for your advice.

 

[cls320cd1]

B2b charger, have a look into it. The smart ones work with the vehicle and controls how much they charge.
Leisure battery, 100ah if possible, then an inverter, suggested to have an inverter twice as big as you need. So if 320watts running you want an inverter 600 Watts running, 1200w peak.

 

[LostKiwi]

In theory a voltage sensitive relay should do what's required.
It connects to the existing battery and when it detects the alternator output rising to charge the main battery will kick in to charge the secondary battery.

The only issue in this scenario is that if the primary battery is fully charged the alternator won't kick in to charge it so the secondary may not get charged even if completely flat.

 

[cls320cd1]

In theory a voltage sensitive relay should do what's required.
It connects to the existing battery and when it detects the alternator output rising to charge the main battery will kick in to charge the secondary battery.

The only issue in this scenario is that if the primary battery is fully charged the alternator won't kick in to charge it so the secondary may not get charged even if completely flat.
View attachment 87649

I've got this in my transit, non smart charge its fine, smart charge system can vary

 

[M80]

Is there advantage in a split charge system here?
Assuming the vehicle is only loaded, electrically, while the engine is running.

Have a good day peoples.

 

[LostKiwi]

If the engine is running whenever the Xbox etc is in use no need for anything other than an inverter.