Adding Starter Battery Charging via Solar

[KGCali]

Hi, I have one of Roger Donoghue two 100W Panel Solar installations on my T5.1 Cali using the Victron MPPT SmartSolar charge controller MPPT 75 115 0 and all works great but I now want to charge my Starter Battery via the Leisure Batteries with Solar without changing the MPPT.
I have a Votronic Standby Charger 3065 which will automatically trickle charge the Starter Battery (Max 3A) via the Leisure Batteries just needs connecting to the positive terminals of both the Starter Battery and one of the Leisure Batteries via a 10A fuse.
To achieve this can I just connect the Votronic unit across the Split Charge Relay, left - Leisure Battery + (via 10A fuse) and right - Starter Battery +?
Sounds too simple so thought I'd check with the experts first to see if any issues may arise

 

[Ch1pbutty]

Hi, I have one of Roger Donoghue two 100W Panel Solar installations on my T5.1 Cali using the Victron MPPT SmartSolar charge controller MPPT 75 115 0 and all works great but I now want to charge my Starter Battery via the Leisure Batteries with Solar without changing the MPPT.
I have a Votronic Standby Charger 3065 which will automatically trickle charge the Starter Battery (Max 3A) via the Leisure Batteries just needs connecting to the positive terminals of both the Starter Battery and one of the Leisure Batteries via a 10A fuse.
To achieve this can I just connect the Votronic unit across the Split Charge Relay, left - Leisure Battery + (via 10A fuse) and right - Starter Battery +?
Sounds too simple so thought I'd check with the experts first to see if any issues may arise

View attachment 94720

View attachment 94721

I don't know the answer, interested in how you get on. We looked at doing similar as have alot of excess solar, but decided to keep it simple and just have the exisiting setup with the charge controller tucked away in the Jack cubby hole.

Worked out that It's unlikely that we would run the engine battery flat. We have a small booster pack in case of emergency, which is charged off the existing solar setup. Can also be used to sink pump in our removable kitchen pod so can be used outside the van + comes in handy for awning lights etc.

 

[Amarillo]

Interested in this.

Over Easter we camped in southern Spain for over two weeks without moving, and somehow drained the starter battery. The alarm went off on the last night, and every time a door is opened the dashboard fires up and starter battery powered lights come on. We also had an iPod plugged into the data USB port and I think this was playing away on silent 24/7.

Anyway, for whatever reason, the starter battery flattened. Being able to get the engine going from a full leisure battery, always topped up from solar, with a simple flick of a switch would save the embarrassment of having to get the campsite to jump start us.

 

[yossarian]

I was parked up for two + months and simply bridged the split charge relay with a fuseholder containing a 7A fuse. That worked well enough that i will do the same in similar circumstances.

I did have the part on hand so zero cost.

 

[GrumpyGranddad]

Not much help but when I had my solar fitted by Roger I had it wired to also charge the starter battery. From memory Roger ran a single wire from the rear somewhere (I’m guessing it was from the Charge Controller) to the relay under the passenger seat.

 

[KGCali]

Not much help but when I had my solar fitted by Roger I had it wired to also charge the starter battery. From memory Roger ran a single wire from the rear somewhere (I’m guessing it was from the Charge Controller) to the relay under the passenger seat.

I assume Roger fitted the dual charging MPPT to your solar system for both starter and leisure batteries so easy just to run a wire up to the split charge relay. I only have a single MPPT so just trying to find a solution without replacing the MPPT.

 

[KGCali]

Interested in this.

Over Easter we camped in southern Spain for over two weeks without moving, and somehow drained the starter battery. The alarm went off on the last night, and every time a door is opened the dashboard fires up and starter battery powered lights come on. We also had an iPod plugged into the data USB port and I think this was playing away on silent 24/7.

Anyway, for whatever reason, the starter battery flattened. Being able to get the engine going from a full leisure battery, always topped up from solar, with a simple flick of a switch would save the embarrassment of having to get the campsite to jump start us.

You can use the leisure battery to charge the starter battery but not jump start it due to the current required, that's why I want my solar to automatically charge the starter battery but I don't want to change the solar MPPT.

 

[Roger Donoghue]

Hi, I have one of Roger Donoghue two 100W Panel Solar installations on my T5.1 Cali using the Victron MPPT SmartSolar charge controller MPPT 75 115 0 and all works great but I now want to charge my Starter Battery via the Leisure Batteries with Solar without changing the MPPT.
I have a Votronic Standby Charger 3065 which will automatically trickle charge the Starter Battery (Max 3A) via the Leisure Batteries just needs connecting to the positive terminals of both the Starter Battery and one of the Leisure Batteries via a 10A fuse.
To achieve this can I just connect the Votronic unit across the Split Charge Relay, left - Leisure Battery + (via 10A fuse) and right - Starter Battery +?
Sounds too simple so thought I'd check with the experts first to see if any issues may arise

View attachment 94720

View attachment 94721

You are correct - that device will charge your starter from your LBs (and consequently, from solar) by simply connecting it to either side of the relay - as either side of the relay in question go directly to each battery(ies).

I've not read the full spec yet, but no reason it should not work. It must need earthing too but I can't see round the whole device.

I'll ook into it more later. Could be a useful thing to sell, though being Votronic I assume it's expensive!

 

[Roger Donoghue]

Done some limited research (need to go out and make solar kits now!) and it seems it is simply two resistors and a diode inside. - so the resistors limit the current flow, and the diode prevents reverse charging.

That's not something I want to sell. Might work well for you but I was suspicious of how a DC-DC charger was so cheap (and has no earth). It's not. It's a current limited diode setup - it will always put around 0.6amp minimum into your starter.

At least that was an Amazon review. I'll research more later.

 

[KGCali]

Done some limited research (need to go out and make solar kits now!) and it seems it is simply two resistors and a diode inside. - so the resistors limit the current flow, and the diode prevents reverse charging.

That's not something I want to sell. Might work well for you but I was suspicious of how a DC-DC charger was so cheap (and has no earth). It's not. It's a current limited diode setup - it will always put around 0.6amp minimum into your starter.

At least that was an Amazon review. I'll research more later.

You are correct, I was given the unit from a friend that sold his camper, he has had it on for a year and all working fine. It works but it is very basic inside, I opened it up, see pictures, and it is just a diode, resistors and small caps, very basic for the asking price around £35. Only issue is it could slowly drain the leisure batteries over winter if no sun for a long period and the Cali's not driven much.
Roger, I think this Victron unit may be better for you to sell as an upgrade to your solar systems, any thoughts?

Cyrix Battery Combiners - Victron Energy

Automatically connect batteries in parallel when one of them has reached a pre-set voltage using the Cyrix Battery Combiners. Find a dealer near you.

www.victronenergy.com

 

[Nand0]

When I bought my California (used) it came with a solar setup by calisolar, with a 120w version. I've been trying to put together how it is installed, as I will likely be making some modifications.

To my surprise, when I lifted the driver's seat to have a look at the battery compartment there, I found that the split charge relay had been replaced with a Votronic VCC 1212-30. I think these are specifically recommended for Euro 6 vans, so probably not necessary for a T5, but looks like a good piece of kit. It will trickle charge the starter battery, and will charge the leisure batteries to 100% when driving.

 

[KGCali]

When I bought my California (used) it came with a solar setup by calisolar, with a 120w version. I've been trying to put together how it is installed, as I will likely be making some modifications.

To my surprise, when I lifted the driver's seat to have a look at the battery compartment there, I found that the split charge relay had been replaced with a Votronic VCC 1212-30. I think these are specifically recommended for Euro 6 vans, so probably not necessary for a T5, but looks like a good piece of kit. It will trickle charge the starter battery, and will charge the leisure batteries to 100% when driving.

View attachment 94892

Good for the bluemotion T6 but not the T5 as that model already performs this function of charging the leisure and starter batteries when driving or on EHU but I just wanted to utilise the excess solar energy for charging the starter.

Think I may go for this Victron unit ...

Cyrix Battery Combiners - Victron Energy

Automatically connect batteries in parallel when one of them has reached a pre-set voltage using the Cyrix Battery Combiners. Find a dealer near you.

www.victronenergy.com

 

[Nand0]

I would have thought that trickle charging of the starter battery would happen when on hookup or when on solar. I don't know this for sure, but if the unit detects a "charging voltage" on the leisure side, regardless of source (solar or hookup) it can send some trickle charge to the starter battery.

I am speculating here, but when I have the van out during the day, if I find the time I'll check it as I would also like to know

 

[RSMarco]

Interested in this as I have also been given a Votronic Standby Charger.

 

[RSMarco]

@KGCali
Have you completed the installation yet?

 

[KGCali]

Not yet, may use the Cyrix unit I mention above.
The Votronic unit should be fine if you want to constantly trickle charge the starter battery from the leisure but I wanted a more 'intelligent' system. I'll decide once I'm back home.

 

[RSMarco]

Not yet, may use the Cyrix unit I mention above.
The Votronic unit should be fine if you want to constantly trickle charge the starter battery from the leisure but I wanted a more 'intelligent' system. I'll decide once I'm back home.

Cheers, interested to see the results.

 

[grainflow]

Any update on this @KGCali ? Did you fit the Cyrix unit in the end? I'm looking at doing the same as I have a T5 that I want to trickle charge the starter battery of EHU and excess solar..

 

[KGCali]

Any update on this @KGCali ? Did you fit the Cyrix unit in the end? I'm looking at doing the same as I have a T5 that I want to trickle charge the starter battery of EHU and excess solar..

Still haven't got around to it as other jobs have taken priority and my starter battery is holding up fine. I'll post if I do anything further

 

[sidepod]

You are correct - that device will charge your starter from your LBs (and consequently, from solar) by simply connecting it to either side of the relay - as either side of the relay in question go directly to each battery(ies).

I've not read the full spec yet, but no reason it should not work. It must need earthing too but I can't see round the whole device.

I'll ook into it more later. Could be a useful thing to sell, though being Votronic I assume it's expensive!

Surely the charging device will need two distinct outputs? Connecting a single power source across both sides of the split charge relay with effectively make it redundant and both starter and leisure batteries will be treated as one and drain as one?

 

[yossarian]

Surely the charging device will need two distinct outputs? Connecting a single power source across both sides of the split charge relay with effectively make it redundant and both starter and leisure batteries will be treated as one and drain as one?

I think they are talking about the device shown in post #10 https://vwcaliforniaclub.com/threads/adding-starter-battery-charging-via-solar.45174/post-586018

Basically a diode and current limiting resistor. Doesn't actually require a ground.

 

[kave]

I think they are talking about the device shown in post #10 https://vwcaliforniaclub.com/threads/adding-starter-battery-charging-via-solar.45174/post-586018

Basically a diode and current limiting resistor. Doesn't actually require a ground.

The batteries are already sharing the same ground, would be strange to have two different grounds in the van. I use a Votronic with two cigarette lighter males with only plus side wired up and have connected it between the dashboard 12v outlet and a rear one. When I change the leisure battery next weeks I will see if I find engine battery + under the seat and hard wire the votronic. It has been working very well for us.

 

[RSMarco]

Would this be an option?

Sterling Battery-Battery Maintainer 12V-12V, 3A

The Sterling B2B Maintainer diverts a small current from a charging source to a second battery, preventing self-discharge & extending battery service life.

www.12voltplanet.co.uk

 

[yossarian]

Would this be an option?

Sterling Battery-Battery Maintainer 12V-12V, 3A

The Sterling B2B Maintainer diverts a small current from a charging source to a second battery, preventing self-discharge & extending battery service life.

www.12voltplanet.co.uk

Yes, this looks like it fits the bill if you have solar and want to trickle charge your starter battery with the excess. A simple voltage controlled DC DC converter on at 13.3v and off at 12.8v

This will not help to increase the maximum park up time of your vehicle if you don't have something charging your leisure batteries.

Quiescent current 2mA.

The votronic device although primitive would be preferable for park up time extension.

 

[RSMarco]

Yes, this looks like it fits the bill if you have solar and want to trickle charge your starter battery with the excess. A simple voltage controlled DC DC converter on at 13.3v and off at 12.8v

This will not help to increase the maximum park up time of your vehicle if you don't have something charging your leisure batteries.

Quiescent current 2mA.

The votronic device although primitive would be preferable for park up time extension.

Yes agree if you already have solar on the leisure batteries.