Lithium Battery for camper

stevemc181

Well-Known Member
Ok, i've been having a think about it and as you pointed out, I think there will be problems having the two batteries negs connected. As this was only for voltage monitoring on the start battery using the same device (Victron-702) and trying to save the need for another gauge on the dash, I think I'll just forget that idea and monitor the start battery with a separate meter. Basically keeping the systems separate apart from the DC-DC charger connection.

I can use the Victron BMV-700 instead on the Aux battery which will be about $100 cheaper anyway. Thanks for your input CampingTechAust :) can you see any other issues in the attached revised diagram?
 

Attachments

  • LIFEPO4 Dual battery Proposed Wiring.pdf
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G'Day,

Thanks for the larger cct diagram. much easier to read now.

Just some comments from the larger diagram...
- I'm not sure the contactor will work as intended. Can you advise what this is for?
- I would still be tempted to have an inline fuse for the current shunt and BCU-PPAK-4C unit but this is up to you.
- With the Redarc unit having a form of LVD functionality onboard, why the need for start battery monitoring?
- Confirming the Battery isolator is on the negative lead?
- Redarc Earth to Chassis or aux battery negative terminal, not the current shunt as shown.

Have you thought about solar or recharging from mains? If so you may want to make changes to the blue wire and red wire of the Redarc unit to accommodate this now. Have a look at how I wired my camper here (circuit diagram about half way down) https://sites.google.com/site/campingtechnologiesaustralia/our-camping-setup-No1

Happy to answer any questions you may have.

Great setup! Looking forward to seeing how it goes.
 

stevemc181

Well-Known Member
G'Day,

Thanks for the larger cct diagram. much easier to read now.

Just some comments from the larger diagram...
- I'm not sure the contactor will work as intended. Can you advise what this is for?
The contactor is a part of the supplied BCU-PPAK and is a magnetic latching relay. Parts of the diagram are directly from the Lifepo4 manufacturers wiring diagram and I have just added bits in as required. (See attached PDF on the BCU-PPak)

- I would still be tempted to have an inline fuse for the current shunt and BCU-PPAK-4C unit but this is up to you.
I'll be picking up the unit today, so will discuss with the supplier regarding this.

- With the Redarc unit having a form of LVD functionality onboard, why the need for start battery monitoring?
Only for when I have the vehicle ignition/accesories on and running the winch/stereo etc, just to give me an idea of main battery voltage.

- Confirming the Battery isolator is on the negative lead?
I will probably move this up closer to the battery, but will also discuss with them today, not sure if it should be on neg or pos?

- Redarc Earth to Chassis or aux battery negative terminal, not the current shunt as shown.
I am thinking all negs need to be connected on the load side of the Negative shunt to monitor both input and output with the Victron-700 unit? If I wire this directly to the neg terminal, then the Victron won't know when a charge is being placed into the battery and will only see the current drain on the load side? I am also thinking I may need to run the earth to ground from the Distribution block instead of from the battery terminal.

Have you thought about solar or recharging from mains? If so you may want to make changes to the blue wire and red wire of the Redarc unit to accommodate this now.
I won't need solar for now, but will occasionally hook up a lifepo4 mains charger so will have a look at this in more detail.

As mentioned, I'll be going over the diagram today with the battery supplier and once I get it right, I'll revise and upload again. The drawings are just preliminary and to try and get it right in my head how this all needs to go together. I am no wiring guru, so your help and input is appreciated.

Have a look at how I wired my camper here (circuit diagram about half way down) https://sites.google.com/site/campingtechnologiesaustralia/our-camping-setup-No1
Looks good, I have probably over complicated my system a bit due to the Victron monitoring etc, but once it is all set-up, it will give me as good as I can get for monitoring SOC etc, I don't want to drop the Lifepo4 below about 70-75% DOD for battery longevity reasons and this is the best way I can think of for doing that. The lifepo4 will stay above 12volts until about 90% DOD and then begin to drop off, so just voltage monitoring really doesn't tell me a lot about the actual SOC.

Happy to answer any questions you may have.
Great setup! Looking forward to seeing how it goes.
Your help is very appreciated, always good to have another set of eyes raising questions and advising if necessary, this has been a steep learning curve for me, but hopefully I'll get it all running as it should be :)
 

Attachments

  • BCU-PPAK-4C-manual.pdf
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The contactor is a part of the supplied BCU-PPAK and is a magnetic latching relay. Parts of the diagram are directly from the Lifepo4 manufacturers wiring diagram and I have just added bits in as required. (See attached PDF on the BCU-PPak)

OK - Will have a look at the manual and come back if I have any other questions

I'll be picking up the unit today, so will discuss with the supplier regarding this.
OK

Only for when I have the vehicle ignition/accesories on and running the winch/stereo etc, just to give me an idea of main battery voltage.
Good idea - I don't have a winch so isn't in my front of mind but makes sense for you.

I will probably move this up closer to the battery, but will also discuss with them today, not sure if it should be on neg or pos?
Check with the supplier - We normally install isolation on the Neg

I am thinking all negs need to be connected on the load side of the Negative shunt to monitor both input and output with the Victron-700 unit? If I wire this directly to the neg terminal, then the Victron won't know when a charge is being placed into the battery and will only see the current drain on the load side? I am also thinking I may need to run the earth to ground from the Distribution block instead of from the battery terminal.

Not sure if I should retract my comment about this one... The issue is that electrically tying the negs to the load side is correct but the link to chassis off the auxiliary throws a spanner in the works. Current shunts normally sit between the chassis and the neg terminal and everything is tied back to chassis to ensure all current is monitored by the shunt. This is how your Paj starter battery is wired. I can't recall if the Redarc case is chassis ground or not. If it is, and the case of the redarc is bolted / screwed onto the chassis of your vehicle, your circuit will short out the current sensing. I think to leave with all negs on the load side of the shunt, the link from the neg terminal to chassis has to go or change everything to match your car and use chassis ground throughout the installation.

I won't need solar for now, but will occasionally hook up a lifepo4 mains charger so will have a look at this in more detail.
OK

As mentioned, I'll be going over the diagram today with the battery supplier and once I get it right, I'll revise and upload again. The drawings are just preliminary and to try and get it right in my head how this all needs to go together. I am no wiring guru, so your help and input is appreciated.
Your welcome - happy to help

Looks good, I have probably over complicated my system a bit due to the Victron monitoring etc, but once it is all set-up, it will give me as good as I can get for monitoring SOC etc, I don't want to drop the Lifepo4 below about 70-75% DOD for battery longevity reasons and this is the best way I can think of for doing that. The lifepo4 will stay above 12volts until about 90% DOD and then begin to drop off, so just voltage monitoring really doesn't tell me a lot about the actual SOC.
It will be a very good system once working.

Your help is very appreciated, always good to have another set of eyes raising questions and advising if necessary, this has been a steep learning curve for me, but hopefully I'll get it all running as it should be :)
Again - your welcome.
 
Hi Again,

A quick look at the diagram for the BCU-PPak shows the brown wire from the Redarc unit should go to the same wire as goes to the pos terminal on your fused distribution box.

Also the Redarc unit will turn off if the contactor ever goes open circuit and disconnects the battery.
 

stevemc181

Well-Known Member
Hi Again,

A quick look at the diagram for the BCU-PPak shows the brown wire from the Redarc unit should go to the same wire as goes to the pos terminal on your fused distribution box.

Also the Redarc unit will turn off if the contactor ever goes open circuit and disconnects the battery.


Ok, I've picked the unit up and had a good go over the wiring diagram with the supplier. As you mentioned and I suspected was the case, I will now run the earth to ground from the Distribution box. They recommend isolation on the Positive wire and also on the distribution box side of the latching relay. I will also change the brown wire as you suggested and connect it as shown.

A fuse from the BCU-PPAK is not absolutely neccesary as the unit is internally fused, but he reckons I can throw a 3 amp fuse on there if desired.

They also recommended setting the Peukert exponent as close to 1 as I could get on the victron (1.1 will be it) and also the Charge Efficiency Factor to 98%. This should give a very good indication of usage.

I'll have a look at the redarc connection side of things later, and probably just throw a changeover relay in there when required for solar etc. At the moment I am going to wire the blue ignition wire to a dash switch, so I can turn the Redarc unit off if desired, basically for my own measuring of how long the battery lasts me when camping etc without being charged. I will be adding in an interface to the Victron unit for connecting to my laptop and reading historical data etc. Can't get a hold of the interface at the moment though, so will add that in later.

A photo of the unit below, I weighed this complete set-up and it comes in at exactly 14Kg's! Nice and light for the amount of power it will put out! I have also attached the latest revised wiring diagram, hopefully this should do the trick!

IMG_1946_zps4da0fcd4.jpg
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Attachments

  • LIFEPO4 Dual battery Proposed Wiring.pdf
    352.6 KB · Views: 314
Last edited:
Ok, I've picked the unit up and had a good go over the wiring diagram with the supplier. As you mentioned and I suspected was the case, I will now run the earth to ground from the Distribution box. They recommend isolation on the Positive wire and also on the distribution box side of the latching relay. I will also change the brown wire as you suggested and connect it as shown.

A fuse from the BCU-PPAK is not absolutely neccesary as the unit is internally fused, but he reckons I can throw a 3 amp fuse on there if desired.

They also recommended setting the Peukert exponent as close to 1 as I could get on the victron (1.1 will be it) and also the Charge Efficiency Factor to 98%. This should give a very good indication of usage.

I'll have a look at the redarc connection side of things later, and probably just throw a changeover relay in there when required for solar etc. At the moment I am going to wire the blue ignition wire to a dash switch, so I can turn the Redarc unit off if desired, basically for my own measuring of how long the battery lasts me when camping etc without being charged. I will be adding in an interface to the Victron unit for connecting to my laptop and reading historical data etc. Can't get a hold of the interface at the moment though, so will add that in later.

A photo of the unit below, I weighed this complete set-up and it comes in at exactly 14Kg's! Nice and light for the amount of power it will put out! I have also attached the latest revised wiring diagram, hopefully this should do the trick!

14kg's! That's awesome at 7Ah per kilo! Wish my Jayco supplied Bosch was that good...
Post some more pics once you get it all in but I think your all good now...
 

stevemc181

Well-Known Member
14kg's! That's awesome at 7Ah per kilo! Wish my Jayco supplied Bosch was that good...
Post some more pics once you get it all in but I think your all good now...

Yep it is pretty awesome when you consider the depth of discharge available as well. Speaking with him today he reckons DOD to 80% won't be a problem, but for best battery life I'll keep it above 70% DOD, which should be good for in excess of 2000 cycles! That's over 6 years if charged and discharged daily! So I would expect I should easily get 10 years plus out of this battery, I guess time will tell!

I am waiting on a few other bits and pieces to turn up in the mail, then I'll get this all together and get some pics up in the next couple of weeks.
 

stevemc181

Well-Known Member
I have basically finished the install into my rear drawer system in the back of the Paj, just need to add in the Redarc when it arrives in the post and tidy up some wiring etc and she is all good to go!

I was in a rush today to get it done and dusted, but ran out of time to add the finishing touches. The Victron monitor is installed in the dash, but difficult to read from the drivers seat, so I might need to make up an angled mount for it. Also still need to add in another bracket to hold the battery in place a bit better than it currently is.

I opted not to add in a shut off switch, as the BCU-PPak has an on/off button that shuts down power to the Distribution box anyway. A couple of pics below of the finished result.

17176e32f4b138a8c63f1eb1865f9c6d_zpsaf3a5244.jpg


991e54c8091c37ef712e17585db7daba_zpsc8a00c7c.jpg
 

Batwoman

Member
Well I was getting ultra excited about this, but as usual have been left way behind.
Was hoping that it was just a case of getting the LiFe battery, Redarc BMS and an Anderson plug.
Eventually solar panels to recharge.
Looks like this is awhile away as main stream, esp for those of us who don't do any electrical stuff.
But will watch this space, as the weight is a really important fact for me.
This is especially funny as currently (pun intended) I don't run anything electrical, but the fridge is next on the wish list....so over sourcing ice.
 

stevemc181

Well-Known Member
Well I was getting ultra excited about this, but as usual have been left way behind.
Was hoping that it was just a case of getting the LiFe battery, Redarc BMS and an Anderson plug.
Eventually solar panels to recharge.
Looks like this is awhile away as main stream, esp for those of us who don't do any electrical stuff.
But will watch this space, as the weight is a really important fact for me.
This is especially funny as currently (pun intended) I don't run anything electrical, but the fridge is next on the wish list....so over sourcing ice.

Lifepo4 tech has a way to go before it becomes mainstream, but it is improving all the time as more and more manufacturers come onboard. A lot of the pieces in my set up are not absolutely essential and cheaper alternatives can be sourced.

Lingona has a system called the 'Outback Buddy' for about $1000 that is in a self contained box and includes a 10 amp charger, but forget their advertising blurb of 180 a/h battery. it's only a 100a/h Lifepo4, but they claim 180a/h lead acid equivalent. The whole set up weighs 20kg's, and they don't use a BMS, which is a concern for longevity. These guys build a lot of Lifepo4 systems for the mines in the Hunter Valley. I almost bought this system but it was too large for where I wanted to fit it and the lack of a BMS concerned me.
http://www.lingona.com.au/img/images/portfolio/The_BLUE_outback_buddy_by_Lingona.pdf
 

Chatty

Well-Known Member
I don't want to appear like I'm knocking what you've achieved here, but I have to ask if it is really worthwhile.

Looking at the setup, it takes a fair bit of room, it's relatively complicated and appears that the majority of the parts are not the sort of things you will find in most country towns should something fail out on the road. Assuming that the lithium battery is 60% more efficient than a lead-acid battery (and I think that's a pretty big assumption - it's more likely only 30% more efficient) your setup would require a 180AH deep cycle battery to match your 100AH lithium.

That being so, I could buy two 100AH deep cycle batteries for $350 ($173 each), add a CTEK D250S charger for around $225 for a total cost of less than $600 - but at the penalty of about 48kg in weight against your 18kg (I have allowed a few kg for your chargers, etc). Even if I add the CTEK SMartPass, I'm still only around the $800 mark - enough change left over to replace the batteries in three years or so.

A 30kg weight saving is nice, but only about the weight of our tent when it's all said and done.

As I said, I'm not knocking what you've done - I would not have known where to start with a setup like that and would automatically have gone down the lead-acid path because that's what I understand.

It is certainly food for thought and I know there always has to be early adopters for new technology to get a start in the market, but as I said some time ago, I don't think lead-acid is dead just yet.
 

stevemc181

Well-Known Member
I don't want to appear like I'm knocking what you've achieved here, but I have to ask if it is really worthwhile.

Looking at the setup, it takes a fair bit of room, it's relatively complicated and appears that the majority of the parts are not the sort of things you will find in most country towns should something fail out on the road. Assuming that the lithium battery is 60% more efficient than a lead-acid battery (and I think that's a pretty big assumption - it's more likely only 30% more efficient) your setup would require a 180AH deep cycle battery to match your 100AH lithium.

I won't really know if it's worthwhile or not for about another ten years :D
One of the deciding factors in going down this route was also the environmentally friendly aspects of the lifepo4, it is far easier and safer to dispose of than a lead acid based battery.

The cavity in the front of the drawer system measures about 900mm Wide x 290mm High x 180mm Deep, this also houses my compressor and light bar drivers, so it is a bit more compact than it looks, I have spread the components out a bit and could easily fit this all in a smaller space by mounting some of the components on the cavity roof etc, but I didn't see the need to condense it much more.

I would say it is a safe bet to call the lifepo4 40-50% more efficient, although in the interests of battery longevity, I won't be taking this battery past 80% DOD if I can help it, and will probably limit it to more like 70%-75% DOD, this should easily give me in excess of 2000-3000 full cycles. I am expecting ten years+ from this battery. Only time will tell! I would say my setup is more like a 150-160 a/h Deep cycle equivalent.

Spare parts in country towns is no big issue, I can easily bypass the BMS if required for emergency use until I can replace it if necessary. All other parts are easily sourced, I could swap the system over to a standard Lead acid if I had to and just plug it into the distribution box.

That being so, I could buy two 100AH deep cycle batteries for $350 ($173 each), add a CTEK D250S charger for around $225 for a total cost of less than $600 - but at the penalty of about 48kg in weight against your 18kg (I have allowed a few kg for your chargers, etc). Even if I add the CTEK SMartPass, I'm still only around the $800 mark - enough change left over to replace the batteries in three years or so.
You will probably be on your 3rd or 4th set of batteries by the time I need to change mine. The actual battery I have is about $500 without the BMS, I just need to swap it all over when the time is due, I would expect in ten years these will be commonplace and a lot cheaper.
I could have installed this system at around $1300 using a cheaper dc-dc charger, but I have elected to go the whole hog monitoring wise and use the Victron BMV-702 to monitor every amp in and out right down to watts being consumed. I can switch on a device and immediately see what current or watts it is consuming and also length of time that my battery can sustain the load for. With this set-up I can also look at the historical data, which will give me a good overview in years to come of the actual battery and system performance.

If you go somewhere like ARB and have a dual battery system installed with DC-DC charger, you won't get much change out of $1500, so I don't think it is an excessive amount to spend and it is certainly a far better system than most out there.


A 30kg weight saving is nice, but only about the weight of our tent when it's all said and done.
Not just the weight, but you will also use additional space with two batteries, or one large 160a/h battery.

As I said, I'm not knocking what you've done - I would not have known where to start with a setup like that and would automatically have gone down the lead-acid path because that's what I understand.

It is certainly food for thought and I know there always has to be early adopters for new technology to get a start in the market, but as I said some time ago, I don't think lead-acid is dead just yet.

I have always been an early adopter of new technology, but I haven't always had the means to do so, but now I do and am enjoying the challenge. :) The Lifepo4 set-up is not that much different to the Lead-acid, it's just the battery input/output is a bit more critical as overcharge/undercharge will kill a lifepo4 much faster than a lead acid. Hence why I have spent the extra dollars on monitoring and an additional low/high voltage shut-off.
 

Chatty

Well-Known Member
All sounds fair enough to me, but I currently run a 75AH dual battery and a 85AH Thumper with solar panel so I'm all set for power for the foreseeable future - perhaps even the next 10 years...

Sent from my GT-I9505 using Tapatalk
 

stevemc181

Well-Known Member
All sounds fair enough to me, but I currently run a 75AH dual battery and a 85AH Thumper with solar panel so I'm all set for power for the foreseeable future - perhaps even the next 10 years...

Sent from my GT-I9505 using Tapatalk

Not knocking what you have, but you mention how much room my system takes up and then post this ? These systems are like chalk and cheese, there is just no comparison. Your dreaming if you think you'll get anywhere near 10 years out of either battery! How much was that thumper and 75ah dual battery?
 

Chatty

Well-Known Member
Not knocking what you have, but you mention how much room my system takes up and then post this ? These systems are like chalk and cheese, there is just no comparison. Your dreaming if you think you'll get anywhere near 10 years out of either battery! How much was that thumper and 75ah dual battery?

Agreed, they are chalk and cheese - in your photos your system looked very bulky, but as you explained there are other things there which take up extra room.

Dual battery came with the vehicle, so nil cost, and around $120 to replace the battery recently after 4 years in my ownership, 3 years old when I bought it, so around 7 years total.

Yes, the Thumper wasn't cheap, but I needed a portable solution which was vehicle/solar/mains compatible which it is and could be instantly transferred between vehicles, which it can.
Only 4 years old at the moment, but no signs of aging yet, so expect to get at least another couple of years out of it and at current prices I expect to pay around $300 to replace the batteries when they eventually fail.

Based on my experience to date I most likely won't get 10 years, but 7 years actual usage from the dual and looking likely for at least the same from the Thumper. Based on the age of a couple of gel cells I have in the garage for standby power at home 10 years is not out of the question. If I'm dreaming, I have yet to wake up.

I don't have the room for a setup the size of yours, but I don't have a camper either - tents being our preference. The dual battery effectively takes up no room, being in the engine bay in space I would not otherwise be using. The Thumper usually sits in the rear seat floor well when in transit, being shoebox size.

Sent from my GT-I9505 using Tapatalk
 

stevemc181

Well-Known Member
Agreed, they are chalk and cheese - in your photos your system looked very bulky, but as you explained there are other things there which take up extra room.

Dual battery came with the vehicle, so nil cost, and around $120 to replace the battery recently after 4 years in my ownership, 3 years old when I bought it, so around 7 years total.

Yes, the Thumper wasn't cheap, but I needed a portable solution which was vehicle/solar/mains compatible which it is and could be instantly transferred between vehicles, which it can.
Only 4 years old at the moment, but no signs of aging yet, so expect to get at least another couple of years out of it and at current prices I expect to pay around $300 to replace the batteries when they eventually fail.

Based on my experience to date I most likely won't get 10 years, but 7 years actual usage from the dual and looking likely for at least the same from the Thumper. Based on the age of a couple of gel cells I have in the garage for standby power at home 10 years is not out of the question. If I'm dreaming, I have yet to wake up.

I don't have the room for a setup the size of yours, but I don't have a camper either - tents being our preference. The dual battery effectively takes up no room, being in the engine bay in space I would not otherwise be using. The Thumper usually sits in the rear seat floor well when in transit, being shoebox size.

Sent from my GT-I9505 using Tapatalk

My setup is also not in a camper, it is housed in the front cavity of my drawer system in the back of the Pajero. I am also a tent camper, and left the space in the front of the drawers specifically for dual batt and compressor install. My way of doing things is a little bit different to the mainstream, but it works for me :)
I can also transfer the entire drawer system and dual batts etc, to another vehicle easily, just need to cut wings to suit.
 

Chatty

Well-Known Member
My drawers don't have any room to spare as I made them specifically to fit into the Paj cargo space and to fit our fridge. If I get rid of the Paj it will have to be for another Paj if I want to keep the drawers, otherwise I might be in for some heavy duty cut and shut to make them fit something else.

The Paj is the only reasonable 4WD that our fridge will fit in, otherwise it would have to be a 100/120 series, which don't float my boat. Tried telling SWMBO we need a smaller fridge, but apparently it's something to do with wine and cheese capacity...

Sent from my SM-P605 using Tapatalk
 

stevemc181

Well-Known Member
Well I've had the system running for two or three weeks now and no major problems, but just a heads up for anyone contemplating similar. The Redarc BCDC1225LV charger I am using doesn't seem to kick itself into boost mode and seems to perpetually float the batteries at 13.3volt, I think this is probably because I haven't drawn enough from the batteries. I have run them down only as low as 12.9 volt and the charger just adjusts it's output accordingly while in float mode.

I had a chat with Redarc about this and they would only tell me the charger isn't suitable for lifepo4. The charge curve isn't ideal, but it's close enough. My work around for getting the charger into boost mode is to just unplug it from the main power cable and also from the Aux batt for a few seconds every few days, then it starts up straight away in boost and charges the battery to 14.5 before eventually setting back into float mode as expected.

Not ideal, as I wanted a totally autonomous system, so I'll see how it goes when I draw more power from the batteries. If it doesn't kick back into boost mode by itself, I'll look at alternative charging options. My first thoughts were to use a lifepo4 specific DC-DC charger from GSL Electronics, but this has no solar input for future solar panels I might add.

Can anyone here who uses the Redarc charger, specifically the LV models confirm if there charger actually goes into boost mode after floating, and what voltage does it go into boost at? Mine will output the full 25 amps when I am drawing power via accessories etc, but it stays in float while it is doing this and only charges the battery back to 13.3 volts. I had assumed to output 25amps it would need to be in boost, but that doesn't appear to be the case? I don't see this as a lifepo4 specific problem and would be interested in hearing others experiences with this particular charger BCDC1225-LV. It may be as simple as running the batteries down further, so I'll try that and see what happens over the next week when I throw the 2nd fridge in there.
 

Grey Wolf

New Member
Great article and I am interested to see how the setup is faring...

My only comment is regarding:
I would say my setup is more like a 150-160 a/h Deep cycle equivalent.
I'm happy to be corrected on this but my training on Amp hours is that it is a measurement gained by drawing X amps from the battery over 20 hours while maintaining a certain temperature, until it reaches it's particular discharged state. It's no different to measuring litres per minute. It's an independent measurement of the batteries capacity to supply low current power to a load.

So if two different batteries are measured at 100a/h then they both have the same capacity of load draw of 5amps per hour for 20 hours until they reached their 100% discharged state, irrespective of their chemical make up. The DOD is an important factor but if you discharge both to a max 70% then they are both still only going to deliver 70a/h. Weight is really the biggest benefit of the LiFePO4 but it will be a while before I'm willing to part with required cash to save 36kg (2 x AGM's at 32kg each).

I am very keen to hear how the setup is going 16 months on.

Cheers
 
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