"Non-isolating"?

[ChrisN]

Hi folks. I'm reading up on some of the issues people have had with the quaint system VW has for charging the leisure batteries in the T6.1, and thinking about alternatives. I haven't taken delivery yet, so this is perhaps a little premature, but the Australian model has just a single leisure battery, and I'm likely to be using the diesel cabin heater a lot in the winter months, so I'll be relying on the leisure battery for that and for running the fridge and lights etc. The Aussie T6.1 also lacks a EHU for mains power. I'm considering a Victron Orion XS 12/12-50A DC-DC battery charger and note that this is described as a non-isolating charger. In this context what does non-isolating mean? Does this imply that current can flow from the leisure battery back into the starter battery? Thanks.

 

[dspuk]

Solar? Plenty of sun down under

 

[secret lemonade drinker]

Non isolating means that both your engine battery and your leisure battery share the same chassis/ground

 

[WelshGas]

Hi folks. I'm reading up on some of the issues people have had with the quaint system VW has for charging the leisure batteries in the T6.1, and thinking about alternatives. I haven't taken delivery yet, so this is perhaps a little premature, but the Australian model has just a single leisure battery, and I'm likely to be using the diesel cabin heater a lot in the winter months, so I'll be relying on the leisure battery for that and for running the fridge and lights etc. The Aussie T6.1 also lacks a EHU for mains power. I'm considering a Victron Orion XS 12/12-50A DC-DC battery charger and note that this is described as a non-isolating charger. In this context what does non-isolating mean? Does this imply that current can flow from the leisure battery back into the starter battery? Thanks.

I think you need to step back a moment and consider exactly how you'll be using the vehicle.
Will you be on campsites with EHU or camping without.
If with EHU then fitting mains power + a suitable charger is the way forward. NB if you have full electric side doors they should be switched to manual as repeated use will flatten engine battery but on EHU both batteries could be charged with a suitable charger or switchover.
If camping without EHU then you have a problem for extended stays. You have a 75amp leisure battery but only 35+amps are usable without damaging the battery and shortening its life.
A compressor fridge uses 3 amps/hr if run continuously but it switches on and off so your leisure battery could power it for 10hrs or upto 35hrs depending on ambient temperature. The Parking heater takes a lot of amps to start but no more than 1 amp to run the fan and fuel pump but will switch off if the leisure battery voltage drops to 11.5v.
For off grid camping longer than 1 night you need to increase your leisure amps available. Change leisure battery to a larger capacity Lithium battery than can use all the amps, Solar panels 200-300watts for all year round use or a Lithium power bank that can be recharged from mains/solar or vehicle when driving.
Due to the Smart Alternator both engine and leisure batteries are only charged to 80% capacity but there is a Max Charge button on the Dashboard that allows charging to full capacity while driving.

 

[ChrisN]

Thanks for the replies folks. For background, we have travelled within Australia for many years in what might be called an expedition-style camper based on a Toyota Land Cruiser 4wd vehicle, including long-distance remote-area travel (eg Simpson Desert, Anne Beadell "Highway"). That vehicle is equipped with a Webasto heater for the camper, 100Ah lithium in the camper, kitchen and water tanks etc, and a 200w solar blanket. Age and health issues are pushing us to switch to a more sedate travelling mode and hence the T6.1 California, with better fuel economy, easier access, driving comfort, more compact, and easier to park in a motel carpark. The camping options are essential for times when we can't get motel accommodation at short notice (an increasing problem here at the moment with motels often booked out months ahead). At times we will have access to mains power, but often not.

I do have a Victron 15-amp mains charger I can use to charge up the batteries overnight when we have access to mains power. We would rarely stay more than 2 days in one location, so I don’t see the need for solar (but may reconsider if our travelling pattern changes). My experience with lithium batteries shows me that cold weather charging performance can be a concern when the batteries refuse to accept a charge below 5 degrees Celsius, but that a 30-amp or 50-amp DC-DC charger can make up the charge fairly quickly when driving, and I expect that having the battery within the cabin of the vehicle may keep the battery warm enough that this isn’t a significant problem. It’s rare (and very expensive) to find a lithium battery locally that has the built-in self-heating capability. We live in a cold part of Australia with regular overnight temperatures down around minus 5 in winter.

My main concern with the Cali will be the capacity and reliable charging of the leisure battery to support overnight camping for two nights, with a fridge, lighting and the diesel heater. Perhaps the available 35Ah from the AGM leisure battery will be sufficient. If not, I can either double up with another 75Ah AGM in parallel or switch to a 100Ah lithium. I’m reading here that many owners have problems with their leisure battery maintaining a useful charge. Perhaps using the “Max Charge” feature will be sufficient. If not, I’ll install a reliable DC-DC charger. From past experience with my other vehicle that will work as I want it to, as long as the leisure battery is isolated from the starter battery.

Thus, my question in the first post above, about whether the “non-isolating” charger will isolate the leisure batter from the starter battery when the engine is off. Modern VW electrics sound a lot more complex and devious than the systems I have worked with up to now!

Thanks again, and a pic of my “other camper” to share.

 

[WelshGas]

Thanks for the replies folks. For background, we have travelled within Australia for many years in what might be called an expedition-style camper based on a Toyota Land Cruiser 4wd vehicle, including long-distance remote-area travel (eg Simpson Desert, Anne Beadell "Highway"). That vehicle is equipped with a Webasto heater for the camper, 100Ah lithium in the camper, kitchen and water tanks etc, and a 200w solar blanket. Age and health issues are pushing us to switch to a more sedate travelling mode and hence the T6.1 California, with better fuel economy, easier access, driving comfort, more compact, and easier to park in a motel carpark. The camping options are essential for times when we can't get motel accommodation at short notice (an increasing problem here at the moment with motels often booked out months ahead). At times we will have access to mains power, but often not.

I do have a Victron 15-amp mains charger I can use to charge up the batteries overnight when we have access to mains power. We would rarely stay more than 2 days in one location, so I don’t see the need for solar (but may reconsider if our travelling pattern changes). My experience with lithium batteries shows me that cold weather charging performance can be a concern when the batteries refuse to accept a charge below 5 degrees Celsius, but that a 30-amp or 50-amp DC-DC charger can make up the charge fairly quickly when driving, and I expect that having the battery within the cabin of the vehicle may keep the battery warm enough that this isn’t a significant problem. It’s rare (and very expensive) to find a lithium battery locally that has the built-in self-heating capability. We live in a cold part of Australia with regular overnight temperatures down around minus 5 in winter.

My main concern with the Cali will be the capacity and reliable charging of the leisure battery to support overnight camping for two nights, with a fridge, lighting and the diesel heater. Perhaps the available 35Ah from the AGM leisure battery will be sufficient. If not, I can either double up with another 75Ah AGM in parallel or switch to a 100Ah lithium. I’m reading here that many owners have problems with their leisure battery maintaining a useful charge. Perhaps using the “Max Charge” feature will be sufficient. If not, I’ll install a reliable DC-DC charger. From past experience with my other vehicle that will work as I want it to, as long as the leisure battery is isolated from the starter battery.

Thus, my question in the first post above, about whether the “non-isolating” charger will isolate the leisure batter from the starter battery when the engine is off. Modern VW electrics sound a lot more complex and devious than the systems I have worked with up to now!

Thanks again, and a pic of my “other camper” to share.

View attachment 128952

For your planned usage I would replace the present battery with a Lithium battery 80 amp + and fit the DC-DC charger.
As you say, the battery is fitted within the vehicle and if it is cold enough to warrant using the heater then the battery will be warmed as well.

 

[ChrisN]

For your planned usage I would replace the present battery with a Lithium battery 80 amp + and fit the DC-DC charger.
As you say, the battery is fitted within the vehicle and if it is cold enough to warrant using the heater then the battery will be warmed as well.

Thanks WG; so much to learn about this new vehicle. Cheers! Chris.

 

[WelshGas]

Thanks WG; so much to learn about this new vehicle. Cheers! Chris.

Some reading from an expert.

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