Fitting a lithium battery (1 Viewer)

lorger

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I've been having some issues with my 12v system recently and discovered its down to my battery being knackered, we always said when we bought the van new 2 years ago we would change to lithium once this battery was dead, thought it would last longer than this.

I will be getting a local guy/family friend to do the work for me as I've no idea what I need and what to do, this guy was with the AA for 30 odd years and has built several quality vans for himself and others as a side business, he's took early retirement but still does a couple of days on projects. I've seen his vans and I have to say they are decent quality so quite happy to go with him.

I would like to have some info though so I have an idea what I'm looking for, our plan is to buy a KS Energy 125ah Lithium and have an inverter fitted. What and how would you guys recommend fitting, I currently have a 160w solar, battery master and 75/15 controller all fitted by vanbitz. The base vehicle is a 2020 fiat Ducato which I believe has a smart alternator but need to confirm this, we are very light users of electric and can currently survive a week or so in Scotland without EHU, however Lorraine would possibly like to use a hairdryer for a couple of minutes maybe every second day and now we have ebikes we might need to give them a small top up.

Would you recommend a second battery?
More solar?
B2B?
Size of invertor?

and anything else you can think of, just so I know what the guys talking about when we discuss it.
 

Derbyshire wanderer

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Personally I think the most important part is battery capacity for off grid. Like a long range fuel tank for expeditions you need to have enough energy if the refuelling (solar) may be inconsistent. If you know the battery alone will do X days without charging you can easily work out how to increase days v Ah capacity.
Solar wattage can be moderate for summer charging but may need four or five times as much in winter to refill the batteries so roof space can be an issue to accommodate this. Far more difficult to ensure your battery will last if relying on solar and a medium battery.
 
Sep 10, 2012
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Getting the amps back into the battery should be a priority.
If you dont do a lot of touring mileage then more solar but dont know if your controller will support doubling current capacity or what your roof space is like.
B2B will give you the amps but you need to drive somewhere.
2nd battery probably not but make provision just in case.
No idea about inverter.

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Mar 30, 2019
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Inverter size will depend on what you intend to power from it. This will also affect your battery choice as it will need to be capable of discharging fast enough to supply the inverter.
 
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lorger

lorger

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Inverter size will depend on what you intend to power from it. This will also affect your battery choice as it will need to be capable of discharging fast enough to supply the inverter.
This isn’t a must have more of a would like to, possibly a low powered hairdryer for no more than a couple of minutes every couple of days, plus would be in the morning so hopefully all day to recover. We have just bought EBikes and we’re thinking of buying a 12v charger to just top them up, on the odd occasions we may need a faster charge. We won’t be running microwave or kettle so apart from above just lights and normal charging like phones and iPads which we currently do via 12v.
 
Mar 30, 2019
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This isn’t a must have more of a would like to, possibly a low powered hairdryer for no more than a couple of minutes every couple of days, plus would be in the morning so hopefully all day to recover. We have just bought EBikes and we’re thinking of buying a 12v charger to just top them up, on the odd occasions we may need a faster charge. We won’t be running microwave or kettle so apart from above just lights and normal charging like phones and iPads which we currently do via 12v.
The smallest decent hairdryer I could find is 800watts which will equate to approximately 80amps draw on the battery. I've recently fitted a 1200 watt inverter which will just run my microwave. That draws about 130 amps but it's only ever used for a couple of minutes at a time. I have now bought a Nespresso coffee maker the same as I have at home since the inverter will power it 🥳. I know a lot of people frown at the use of microwaves and hairdryers but it keeps my wife happy. Happy wife, happy life 👍

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bigtwin

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The B2B isn’t optional; it’s a necessity if you’re fitting a LiFePo4 battery. A bit of a worry that your fitter isn’t aware of that.

Ian
 
Mar 30, 2019
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The B2B isn’t optional; it’s a necessity if you’re fitting a LiFePo4 battery. A bit of a worry that your fitter isn’t aware of that.

Ian
Surely it depends how you use your van. If you drive a lot and use it all year I agree but if you don't drive long distances, use it mostly in the summer and have a decent amount of solar then a B2B is not really necessary.
 
Sep 24, 2013
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Your bike batteries will be the things that suck the power. We have a couple of them and running the charger from a small inverter pulls around 9 amps for about 5 hours each if fully charging them. We have 180ah of lead acid batteries and 260W of solar so you can see that to recharge both batteries from flat will take all our available capacity. In practice we usually only partially discharge the batteries so charging time is reduced and we have not had an issue over the last few weeks when the sun is shining.

Good luck finding a 12v charger.

I think you need to look at upping the solar capacity.

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lorger

lorger

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The B2B isn’t optional; it’s a necessity if you’re fitting a LiFePo4 battery. A bit of a worry that your fitter isn’t aware of that.

Ian
Where does it say the guy doesn’t know this, I’m asking the question so when he tells me what he recommends I know it’s the correct thing. At this point I’ve only mentioned what I want and he’s said we can discuss it next week.
 
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lorger

lorger

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Your bike batteries will be the things that suck the power. We have a couple of them and running the charger from a small inverter pulls around 9 amps for about 5 hours each if fully charging them. We have 180ah of lead acid batteries and 260W of solar so you can see that to recharge both batteries from flat will take all our available capacity. In practice we usually only partially discharge the batteries so charging time is reduced and we have not had an issue over the last few weeks when the sun is shining.

Good luck finding a 12v charger.

I think you need to look at upping the solar capacity.
There was a post on here last week or so with links to 12v chargers and I’ve had a look for compatible ones for our bike.
 

Mr Mousy

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First moho 11/2013, second 11/2014 current from 09/2019.
For value for money is suggest a combined b2b/mmpt. I’ve just fitted one and it’s working perfectly.


This give a maximum of 30ah charge from the b2b and can handle up-to 400w solar.

They do a 50a version as well.

Use the code welcome5 and get 5% off.

If you decide to buy one please pm me so I can explain how I installed a cut off for the solar while driving.

I appreciate that with a combined unit you run the risk if it conks out of loosing b2b and solar - however at this price I could replace it and still have change from buying a Votronic or Victron system.

lorger

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Sep 17, 2017
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I've got a Voltronic 30A B2B. It requires very little re-wiring because it's only 30A and they provide instructions as to how to run it through my Schaudt Elektroblock really easily. Also, unlike the Victron, it's pretty efficient, so doesn't need extra cooling.

I've bought it, but I haven't fitted it. As last time I opened it all up, I blew my control panel. Although I now think it was faulty to begin with.
 
Jan 28, 2008
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This isn’t a must have more of a would like to, possibly a low powered hairdryer for no more than a couple of minutes every couple of days, plus would be in the morning so hopefully all day to recover. We have just bought EBikes and we’re thinking of buying a 12v charger to just top them up, on the odd occasions we may need a faster charge. We won’t be running microwave or kettle so apart from above just lights and normal charging like phones and iPads which we currently do via 12v.
similar usage to that ,we have a 110 battery 189 of solar and never had a problem no B2B We dont charge bikes

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May 7, 2016
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A 2020 motorhome with a smart alternator should already have some form of B2B, sometimes called a charge booster. The problem of charging leisure batteries with a smart alternator has been known for several years. It may be part of the reason why the original battery has only lasted 2 years, particularly if it is an AGM which are very fussy about getting a proper charge.

Because LiFePO4 batteries have a higher voltage and smart alternators drop the charge voltage, current could flow the wrong way through a split charge relay. The 12V leisure system and the 12V engine system need to be properly separated and the best way of doing this is a B2B.
 

bigtwin

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Where does it say the guy doesn’t know this, I’m asking the question so when he tells me what he recommends I know it’s the correct thing. At this point I’ve only mentioned what I want and he’s said we can discuss it next week.

Apologies, I misread your post. 👍

Ian

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bigtwin

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Surely it depends how you use your van. If you drive a lot and use it all year I agree but if you don't drive long distances, use it mostly in the summer and have a decent amount of solar then a B2B is not really necessary.
With lead acid batteries, I agree. However, as I understand it, with lithium you need a way of limiting the current asked of the alternator (unlike lead acide, lithiums have a very low internal resistance).

ive got a lithium and no B2B works fine for us

Is that because, as Pausim says below, your standard setup includes a B2B?

A 2020 motorhome with a smart alternator should already have some form of B2B, sometimes called a charge booster. The problem of charging leisure batteries with a smart alternator has been known for several years. It may be part of the reason why the original battery has only lasted 2 years, particularly if it is an AGM which are very fussy about getting a proper charge.

Because LiFePO4 batteries have a higher voltage and smart alternators drop the charge voltage, current could flow the wrong way through a split charge relay. The 12V leisure system and the 12V engine system need to be properly separated and the best way of doing this is a B2B.

Ian
 

gerry mcg

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lorger, I've gone with an underseat 200Ah ks-energy LiFePO4 battery in my Globecar, with a 50A votronic vcc1212-50 B2B, 175W solar and a victron 500W inverter, and a victron Bluesmart charger, bypassing the charging circuit of the EBL119.
It was quite simple to wire once I figured out how to do it.
If you are around Glasgow, get in touch and drop by and I can show you what / how I did it 👍🚐
 
Last edited:
Jul 5, 2013
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If your motorhome has a smart alternator it will already have a B2B. Check what size it is. As Vanbitz has worked installed the present solar, ask eddievanbitz as he will probably know.

I think you need more solar and more battery capacity. The more the better if you are planning to use it in winter in Scotland. As for the inverter the largest load will be the hairdryer. If your wife uses a small travel one you will get away with 1500W.

I recently fitted 2 x125Ah K&S lithium batteries as direct replacements to existing AGMs. I also added a B2B because my motorhome did not have one and uprated the solar controller. I already have 250W of solar, but I may add another 100W panel to give it a boost.

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May 7, 2016
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If your motorhome has a smart alternator it will already have a B2B.
Sadly not always the case. Should have a B2B but some manufacturers were vey slow to understand the problem. I had a Hymer Mercedes with a smart alternator but no B2B. Hymer have now got the problem covered. If lorger ‘s 2020 Ducato has one of the new engines it will have a smart alternator but if it was built on an early 2019 chassis it may have come with the smart function disabled.
 

gerry mcg

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One of the easiest ways of checking if you have a smart alternator is to look at the negative terminal of the starter battery. If there is a shunt connected to the negative terminal (black Box) then that is indicative of a smart alternator.

I thought that a number of MH converters were getting their fiat chassis bases supplies without smart alternator much after regular vans were fitted with them due to the specific MH requirements / demands, so it is not certain your 2020 Base van has a smart alternator just by build date
 
May 7, 2016
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One of the easiest ways of checking if you have a smart alternator is to look at the negative terminal of the starter battery. If there is a shunt connected to the negative terminal (black Box) then that is indicative of a smart alternator.

I thought that a number of MH converters were getting their fiat chassis bases supplies without smart alternator much after regular vans were fitted with them due to the specific MH requirements / demands, so it is not certain your 2020 Base van has a smart alternator just by build date
Fiat were disabling the smart alternator function for constructors but the new testing regime that came in on 01/09/2019 stopped that. The new test stopped them from disabling the smart alternator and seems to have forced them to use AdBlue. Some of the old chassis were already in the system by the cut off date and were covered by a derogation. If the OP’s Ducato motorhome has AdBlue it should have a smart alternator and if it doesn’t have AdBlue it probably has a standard alternator.

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Pablotti

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I’m adding lithium to my 2020 Boxer at the moment. The set up is 1x 120ah battery, Victron MPPT, 2x Victron 30a B2B in parallel for 60a of charge, a Victron charger to replace the Sargent system, A smart shunt for monitoring, and a battery master. I’m sticking with the relatively low amount of solar for now, but may add to it later.
 
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With lead acid batteries, I agree. However, as I understand it, with lithium you need a way of limiting the current asked of the alternator (unlike lead acide, lithiums have a very low internal resistance).



Is that because, as Pausim says below, your standard setup includes a B2B?



Ian
No my van has a standard alternator and split charge relay the lithium just dropped in where we had 2 lead acids
 
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lorger

lorger

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Fiat were disabling the smart alternator function for constructors but the new testing regime that came in on 01/09/2019 stopped that. The new test stopped them from disabling the smart alternator and seems to have forced them to use AdBlue. Some of the old chassis were already in the system by the cut off date and were covered by a derogation. If the OP’s Ducato motorhome has AdBlue it should have a smart alternator and if it doesn’t have AdBlue it probably has a standard alternator.
We don't have adblue and I think our chassis is a 2019 model although not sure of the month.

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lorger

lorger

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lorger, I've gone with an underseat 200Ah ks-energy LiFePO4 battery in my Globecar, with a 50A votronic vcc1212-50 B2B, 175W solar and a victron 500W inverter, and a victron Bluesmart charger, bypassing the charging circuit of the EBL119.
It was quite simple to wire once I figured out how to do it.
If you are around Glasgow, get in touch and drop by and I can show you what / how I did it 👍🚐
Thanks for the offer, sods law I was up the west end on Monday and probably won't be back before starting this project.
 

gerry mcg

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Very good chance you don’t have a smart alternator. I would still opt for a B2B, stops the battery from taking too many amps and makes sure the alternator doesn’t overcharge the Li.
+1
I recommend the Votronic vcc1212-50 B2B.
Where are your Leisure batteries? Can you fit 200Ah underseat?

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