Good old Lithium yet again. (3 Viewers)

[AdrianChen]

So I'm thinking let the Ablemail do it's job and wire the relay output of the BMV to a larger relay to switch the input to the solar regulator. Then set the relay to switch on connecting the solar when the battery is at 40% SOC and to switch off when the battery is at 80% SOC.
If I don't fit the BMV and go for a Smart Shunt I could use a voltage comparator to do the same job.

The second option is to fit a changeover switch to the output of the solar regulator and switch it over to the starter battery when parked up at home, so the solar just maintains the starter battery.

Next problem is the fridge as the Victron regulator does not have an AES output.
So I'm thinking of using either the BMV relay or a voltage comparator to switch a 12v signal to the S+ on the fridge when the battery is at 100% SOC and to switch off when the battery is down to 50% or 60% SOC. Also I will fit a 24 hour timer inline so the AES connection will only be active from say 7 am to 4 pm (depending on the time of year) with it switching on & off in one hour blocks. That should preserve the battery and save a bit of gas.

We have an Ablemail on our Carthago, I am planning to use the SW2 to switch on the charging when the leisure batts are below the normal trigger point - I do it manually at the moment but will forget to check at some point..... Not sure if I will use the user defined load output on the solar 100/50 or one of the Cerbo GX relays to do it. My van is in a storage site so I have Victrons Connect/VRM apps and monitor the batteries through that.

The fridge is something I have thought about as well, at the moment we just leave the multiplus inverter on, and the fridge is wired to the inverter so defaults to 240v, the solar just keeps topping up the batteries, not an efficient process, but so far the B2B has kept up while driving, but in the cooler wetter months we have mostly been on sites with ehu so not sure how this will work in the summer when we are off grid - will be a pain having to monitor it so it will be good to hear how you end up doing it...

 

[Ditcha]

I have seriously considered it but with us doing 100 to 150 nights away with perhaps only 5 or 6 of them on EHU I can't really justify it, I haven't ruled it out completely but it would need to be fitted in the garage near the other electrics and if I fit the battery in the original space the 70 mm cables needed will be another 150 quid.

If you go for the multiplus compact with the aluminium casing they come with a metre of cable just a thought and in my view better built.
It's a bit of a minefield ain't it

 

[jumar]

I was referring to external ventilation for heat & safety, never seen an oven fitted without external ventilation before.
Anyway it's something I can always fit later if we want it.

That looks good, I was thinking a halogen oven would be better than a Romiska. The van is a long way off yet.

Lenny...I'm not normally in a position to offer advice to your goodself....but here goes...Halogen Ovens are great...very versatile, we use one in our apartment here in Spain..

 

[stevewagner]

I fitted twin 100amp Lifepo's in our Carthago in the existing battery compartment. I am considering fitting another under the diner seat which is a very short run. I did consider fitting them in the garage but use it for our ebikes, awning and other bits. I also carry a Honda scooter on a rear rack. Although lithiums are considerably lighter at least by utilising the existing battery compartment, most of the weight is on the front axle.

 

[CazPaul]

Here’s my thoughts, our gels will be in their 18th year of use in less than 3 months.

So use the gels for 18 to 20 years and when they are knackered buy lithium, save a fortune

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[the1andonly]

Since going Lithium my Off Grid style has changed so much Lenny... I've even had the confidence to take the hook up cable out of the van...LPG and Solar are plentyful.....

I took out my second cable out but glad i left the burried one in because i ended up on a site where EHU was "free" why use gas when lecy already paid for . But generally off grid.
For Lenny HB choices ignore the Votronics doesn't like Lithium, Its only the 430 that has been reported giving grief. I have a 250 and 350 working for last 2 years with Li. Charging SB no problem, also AES still available for fridge.
I only have 100Ah but 550W solar, 3 seasons of 14 days off grid. No problem running Washing machine. But I dont use Mains equipment often, charging Gtech hoover batteries etc. 280Ah should be enough given your current setup. As to B2B i bought a 30A Votronics based on the principle that if necessary I could add another Battery and another 30A b2b. I also have CBE hardware and use the Mains charger on Gel setting, it gets used once a year. For SOC monitoring i would reccomend a BM712 (as opposed to 700 or smart shunt) as it can control a relay based on whatever you want eg SOC. This can control a SSR to charge the battery in whatever way you want eg 80% SOC. Easily changed to max when on the road. Easy for a man of your calibre. All The info collected by the BMV can also be sent to an Arduino mega if its data you like. As yet i have not talked directly to the Votronics items as not open source unlike Victron, but its not been an hinderence.

 

[Just smiffy]

This all sounds just a little bit fiddly……. I’d get the dealer to do it all……

 

[Lenny HB]

I echo this advise, in the long run this is the best and most economical approach. No charger will match a multiplus. Also it has the bases of a integrated system, the VE bus data can be vied remotely, it has relay, virtual switch all programmable, it can limit the ehu in on weak supply etc. And if you don’t want to splash for a GX, a simple RPI 3+ will do all the integration, solar, bmv and you can also automate for you boiler to use the sun for a shower.
On the battery side, just skip the 280ah, you WILL upgrade later, or always work round it with limitations. When not in use, just leave it at 80% charged and let the abelmail take care of the cab. When drops to 20-30% Soc, set a alarm in vrm to warn you, and turn on a smart plug connected to multiplus to recharge. I have smart plugs that takes care of lots of things in my absence, sometimes over 3 months.

The Multiplus was my first thought but hard to justify with my use pattern but would make wiring easier & not that much more expensive if I decide to ditch the CBE charger.
If I go for a 460 ah battery which I probably with I'm then getting tempted with a 3000 va inverter/Multiplus. I might have to dodge a few rolling pins.

 

[Lenny HB]

This all sounds just a little bit fiddly……. I’d get the dealer to do it all……

Not made of money like you Garry.

 

[Just smiffy]

Not made of money like you Garry.

Well, you know you’d like it done properly Lenny… the dealer will make a soo much better job of it…

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[Hoovie]

OK Guys, have new van coming at sometime in the future and I'm fed up with sleepless nights going over the electrics. So just to see what you all think.

Will be fitting either 280 AH or 460 AH of Lithium & at least a 2000 VA inverter as we have ordered the van without an oven (didn't like where & how it would be fitted).
So we will be using a lot more electrical gear than we normally do, probably a small Air fryer, maybe a Romeska & our 800 Watt kettle a lot of the time.

The Van is a Carthago CompactLine so the electrics will be CBE.
For the mains charging I may leave the CBE charger on the Gel setting initially as we rarely use EHU, not ideal but OK for occasional use.
Other option is to fit a Victron IP22 charger and leave the CBE charger to take care of the starter battery.
A Victron Multiplus would be a nice solution but with our low EHU usage it would be an extravagance.

I would price up the Multiplus vs a separate Inverter of similar quality plus the Charger. The Multipluses seem pricey but when you tot up their features against separate equivalent devices they are actually very cost-effective. One key feature which will save hassles for example is the built-in Auto Transfer Switch.

I will initially fit 300 or 350 watts of solar not sure how much more I can get on the roof, the van will have a B2B as standard, trying to find out which one as a 30 amp won't be much good with 460 AH of Battery.

I don't know the layout of your van, but I did a setup last year on a brand new compact Hymer (can't recall the model but it was a shortie but still had 4 vents on the roof) - we got 500W on the roof (along with a Victron EasySolar (Multiplus 12/100 + 100/50), Cerbo GX, AMT12-2, BMV-712 and a pair of 100Ah Lithiums)

I was original going to fit a Votronic solar regulator as I like the dual output for the starter battery & the AES output for the fridge but a few people have had problems with the Votronic with Lithium.

So I am going to play save and fit either a Victron Smart 100/30 or 100/50 regulator and an Ablemail Battery Maintainer to take care of the starter battery.
The next problem comes is keeping the starter battery topped up when parked up at home. I could plug into the EHU which is next to the van but that goes against the grain, IMO Motorhomes should be self-sufficient.

We all know Lithium's don't like to be stored fully charged or on charge but the starter battery needs to be maintained.
Two options I'm thinking of, I will probably transfer my BMV700 over from my current van or fit a new one or a smart Shunt.

So I'm thinking let the Ablemail do it's job and wire the relay output of the BMV to a larger relay to switch the input to the solar regulator. Then set the relay to switch on connecting the solar when the battery is at 40% SOC and to switch off when the battery is at 80% SOC.
If I don't fit the BMV and go for a Smart Shunt I could use a voltage comparator to do the same job.

I don't know how well a voltage comparator would work with Lithium. The voltage sags on load are actually greater than than the voltage reduction between 100% and 50% SOC!
I would be inclined to leave the BMV-700 where it is and fit a BMV-712. The '2 will give you the ability to monitor the Starter Battery - or you could connect a different battery source to the Aux if you wanted to get creative, and then use the Relay on the BMV to control the Regulator, or the AES connection, or whatever far more accurately than with voltage values. As you will know already, but for other readers, the reason the Smartshunt is not suitable (IMO) is there is no programmable relay on the Smartshunt.

The second option is to fit a changeover switch to the output of the solar regulator and switch it over to the starter battery when parked up at home, so the solar just maintains the starter battery.

Next problem is the fridge as the Victron regulator does not have an AES output.
So I'm thinking of using either the BMV relay or a voltage comparator to switch a 12v signal to the S+ on the fridge when the battery is at 100% SOC and to switch off when the battery is down to 50% or 60% SOC. Also I will fit a 24 hour timer inline so the AES connection will only be active from say 7 am to 4 pm (depending on the time of year) with it switching on & off in one hour blocks. That should preserve the battery and save a bit of gas.

BMV - same logic as above. I use the Relay on one of my BMV-712s to enable the Electric Element (via an SSR) on the water heater at high SOC and disable at a lower SOC. So same principle as you are thinking, just a different product to enliven (I already have a compressor fridge. Before I switched to that, I used the relay to enable the 240V to the 3-way AES fridge at high SOCs).

Next question is for CompactLine owners, mine will be the I 141, the battery compartment is buried amidships in the double floor and looks a right pain to get at. It will accept a 280 AH Lithium the question is with a bit of modding would I be able to get a much larger battery in (460 AH 522mm x 240mm x 218mm).

Also what seems a bit stupid the batty compartment is in the middle of the van the battery cut off switch is about a metre forward of it but the distribution unit is in the other direction in the garage, plain stupid.
I think Motorhome converters employ designers with the logic section of their brains missing.

So I'm thinking of fitting the battery in the garage but that does lose valuable garage space.

 

[Lenny HB]

I would be inclined to leave the BMV-700 where it is and fit a BMV-712. The '2 will give you the ability to monitor the Starter Battery - or you could connect a different battery source to the Aux if you wanted to get creative, and then use the Relay on the BMV to control the Regulator, or the AES connection,

The BMV 700 has programmable relay so as far as I can see for my use the the only advantage the BMV 712 has is starter battery monitoring. Not worried about that a a tracker will monitor the starter battery.
I take your point about voltage is not aan accurate state of charge with Lithium. So it would be wise to use percentage switch settings in the BMV for the AES control and a voltage comparator would be ok to switch the solar on when the SOC starts to get low as this would not be critical as I wouldn't set it too low.

 

[funflair]

The Victron Phoenix Smart inverter 2000 VA which is 1600 watt true power. May go for the 3000 VA if I fit 460 AH of Lithium.
A few good inverters and quite a bit cheaper but nothing comes close to the low standby power of the Victron, very low in Eco mode.

Go for the 3000 Lenny and you can get a proper kettle, life is too short for 800watt kettles .

 

[Lenny HB]

Go for the 3000 Lenny and you can get a proper kettle, life is too short for 800watt kettles .

I like small kettles only use a 1 Lt one at home.

 

[Hoovie]

The BMV 700 has programmable relay so as far as I can see for my use the the only advantage the BMV 712 has is starter battery monitoring. Not worried about that a a tracker will monitor the starter battery.
I take your point about voltage is not aan accurate state of charge with Lithium. So it would be wise to use percentage switch settings in the BMV for the AES control and a voltage comparator would be ok to switch the solar on when the SOC starts to get low as this would not be critical as I wouldn't set it too low.

not the only advantage.
The 712 has a few differences over the 700 which may be useful ...
700 has no Integrated Bluetooth. The BMV head is not that pleasant to programme, especially to setup, control and occasionally overide the relay. You may well have the Bluetooth module for it already, but should you want to get into the VRM world, you would need to remove that to connect a VE.Direct cable and then you lose the Bluetooth (yes, you can still connect via VRM, but sometimes it is handy to just have Bluetooth connection)
With the 712, you can control the relay based not just on conditions for the main battery being monitored, but also on the Starter battery. For example off the top of my head, you might decide to connect the relay to control a starter battery charger and have that come on when the Starter Battery drops to 12.0V. Can't do that with a BMV-700, can ya
The 712 has a different relay to the 700. one difference is it has an NC as well as a NO connection (no great shakes maybe as you can invert the relay function, but actually start thinking out the box and you could end up with dual control relay ). AND ... it is a lower-residual draw relay than the 700. could be important for some. maybe not you, but just addressing the "only difference" comment. Victron recommend the BMV-712 over the other BMVs on a lithium install for that specific reason.

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[Hoovie]

Go for the 3000 Lenny and you can get a proper kettle, life is too short for 800watt kettles .

I had a 2000W Induction Hob in my last camper (driven by the 12/3000) and I always put the kettle on about 500W - found after I put the kettle on, by the time I got the cups out, tea bag out, milk and sugar out, the water was just on the boil. perfect timing. higher setting and would have to turn it off while getting sorted. More power = Slower drink prep in fact

 

[funflair]

I had a 2000W Induction Hob in my last camper (driven by the 12/3000) and I always put the kettle on about 500W - found after I put the kettle on, by the time I got the cups out, tea bag out, milk and sugar out, the water was just on the boil. perfect timing. higher setting and would have to turn it off while getting sorted. More power = Slower drink prep in fact

We have a big teapot

 

[WESTY66]

We have a big teapot

Thanks for the heads up

 

[Hoovie]

We have a big teapot

TMI

 

[Roger S]

We fitted a 230amp lithium a couple of months ago and are using the van to visit family up north (6hrs away ), we overnighted through the tunnel after a couple of hours driving, it was -7 over night so the Alde heating was on a permanently, the tank heaters on for a couple of hours too, we were making tea with the electric kettle etc. We then drove 5 hours to complete the journey the next day and have been parked up for 4 days, 100w of solar so that won't be producing much power in this weather and we still have plenty of power in the battery, it still cold so hearing left on, although it runs on gas it still needs electric for it to run.

My point is are you sure you need 460amp ? Could you try a 230amp thern add another if needed ?

Ps we've used the microwave for 10 or 15 minutes, all through the invertor.

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[jumar]

We fitted a 230amp lithium a couple of months ago and are using the van to visit family up north (6hrs away ), we overnighted through the tunnel after a couple of hours driving, it was -7 over night so the Alde heating was on a permanently, the tank heaters on for a couple of hours too, we were making tea with the electric kettle etc. We then drove 5 hours to complete the journey the next day and have been parked up for 4 days, 100w of solar so that won't be producing much power in this weather and we still have plenty of power in the battery, it still cold so hearing left on, although it runs on gas it still needs electric forl ot to run.

My point is are you sure you need 460amp ? Could you try a 230amp thern add another if needed ?

160aH Lithium is our battery bank... sufficient for our needs....perhaps not for everyone's...

 

[Lenny HB]

Currently have 234 ah of gel, 280 ah of Lithium would give us a bit more power, currently only ever got really low on power once after two weeks on a Sellaplatz in a rainy October (I was in hospital).
But the plan is to use the new van differently as we are not having an oven & plan to run more electrical items so an extra £400 in the overall picture is not a lot as you get 180ah for it. So fairly certain I'll go for the 460ah it will upset 'er indoor she no like me spending money.

 

[Pausim]

Also what seems a bit stupid the batty compartment is in the middle of the van the battery cut off switch is about a metre forward of it but the distribution unit is in the other direction in the garage, plain stupid.
I think Motorhome converters employ designers with the logic section of their brains missing.

The location on my 143 might be different but I think the design is quite clever. The cut off switch can be reached from outside. This means when I arrive I can open the habitation door, lean in to open the hatch, turn the power on and then lower the step. When you have short legs and dodgy knees this makes a big difference. Conversely when leaving I can climb out before taking the step in and isolating the battery. I always take the step in when leaving it in storage, less chance of someone clipping it. The grey water drain tap and hot water drain down are similarly place so that they can be done from outside.

 

[peterc10]

The BMV 700 has programmable relay so as far as I can see for my use the the only advantage the BMV 712 has is starter battery monitoring. Not worried about that a a tracker will monitor the starter battery.
I take your point about voltage is not aan accurate state of charge with Lithium. So it would be wise to use percentage switch settings in the BMV for the AES control and a voltage comparator would be ok to switch the solar on when the SOC starts to get low as this would not be critical as I wouldn't set it too low.

Hhhhhhmmmmm

I have only just noticed the relays on my BMV700. What can I use them for and how I wonder? But if I start looking at the manual I will probably get lost after the first sentence. Victron manuals always assume that I understand what they are talking about.

 

[Lenny HB]

The location on my 143 might be different but I think the design is quite clever. The cut off switch can be reached from outside. This means when I arrive I can open the habitation door, lean in to open the hatch, turn the power on and then lower the step. When you have short legs and dodgy knees this makes a big difference. Conversely when leaving I can climb out before taking the step in and isolating the battery. I always take the step in when leaving it in storage, less chance of someone clipping it. The grey water drain tap and hot water drain down are similarly place so that they can be done from outside.

The battery in the I 143 is much more accessible, I can't see me using the isolator switch very often most Motorhomes don't have them. Carthago's positioning of it is totally stupid as it increases the cable runs causing unnecessary volts drops.
Even if I keep the original battery the position of that switch will be moved.
The grey water drain will be getting an electric valve and camera, I've got used to not moving from the driver's seat when dumping.

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[Raul]

I’ve got the electric valve, I’m interested what camera could be suitable for that location.

 

[Swifter]

Just remember how much those e-bikes take to charge . Good excuse to get the 460ah set up .

 

[Lenny HB]

I’ve got the electric valve, I’m interested what camera could be suitable for that location.

I just used a cheap eBay one I think it was 10 quid decided to give the 5 quid ones a miss.
Just had a look this one looks suitable & you can reverse the image which you need if facing forward. I just glued it on with PU.

Waterproof Wide HD Car Reverse Parking Camera Front/Side/Rear View Sensor Cam | eBay

Perfectly solve the issue of bad car rear view effect. Small compact size. Sensor Area: 5.961mm x 4.276mm. Bullet Point. Low power consumption. Low maintenance. TV system: NTSC. Scanning System: 2:1 Interlace.

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[Pausim]

The battery in the I 143 is much more accessible, I can't see me using the isolator switch very often most Motorhomes don't have them. Carthago's positioning of it is totally stupid as it increases the cable runs causing unnecessary volts drops.
Even if I keep the original battery the position of that switch will be moved.
The grey water drain will be getting an electric valve and camera, I've got used to not moving from the driver's seat when dumping.

To me they are putting customer convenience before cost saving a few €s on cable length and I like that. I agree the voltage drop will be a bit more but they use a good sized cable and I haven’t had any issues.

Will you be motorising the existing grey water valve or fitting one in a new position? The remote mechanics of the original arrangement make it quite stiff and I might be tempted to do something similar. I had thought about it before but didn’t want to use an additional external valve that would sit outside the winterised heated area.

 

[Lenny HB]

Will you be motorising the existing grey water valve or fitting one in a new position? The remote mechanics of the original arrangement make it quite stiff and I might be tempted to do something similar. I had thought about it before but didn’t want to use an additional external valve that would sit outside the winterised heated area.

Depends on the available space it looks tight to motorise the existing valve obviously the best way to do it. If mounting outside it wouldn't be too difficult to put it in an insulated box with a small heating element for extreme conditions.

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