Lithium LifePo4 12v Batteries - Time For An Upgrade?

[Samiguel]

Low temp cut off is a must, and your covered there which is good.

For the heater - where's the van stored when you're not driving it, and it's it in regular use or is it just for summertime and trips away?

The heater might come in useful if it's stored during winter, as with an AMT-12 and a solar panel, you can basically keep the starter battery and leisure battery topped up with no hookup or additional chargers needed, provided it can get enough solar. If you regularly have cold days in winter, no heater might scupper this. Even 15w of solar is 1amp and might be enough to keep everything topped up over winter. It'll depend entirely on now much solar the van would get and how many days below zero you have.


On the BMS side, the Victron app is easier to access than the Fogstar app, and you're already going to be using it with your other Victron kit. 1 app Vs 2.

As for the BMS inaccuracies - that could be a bigger issue if you think you'll be running the battery down to 20% or lower regularly - even with normal use you'll very likely not see the correct % on the BMS, due to low solar days, or just using a few lights etc. so you might find that you're in a situation where you think you have 15% but the battery suddenly cuts off because it's actually at 0%.

Nice one, thank you. The van is a daily driver so the only time it doesn't get driven is the weekends basically. Should have said, the panel is one of the suitcase ones so it's not permanently connected.
I like the idea of having all the data in one app and, as I said, I do trust the Victron kit.

In the summer we went to Scandinavia and got quite good solar, but our AGM battery couldn't quite cope with the fridge so the battery voltage being available in the MPPT app was really handy. With more capacity in the lithium I imagine we are less likely to run it flat, but I suppose knowing an accurate SOC is important for us.

So, save up for a bit longer and get the 105ah battery AND the Smart Shunt?

 

[TallPaul_S]

Nice one, thank you. The van is a daily driver so the only time it doesn't get driven is the weekends basically. Should have said, the panel is one of the suitcase ones so it's not permanently connected.
I like the idea of having all the data in one app and, as I said, I do trust the Victron kit.

In the summer we went to Scandinavia and got quite good solar, but our AGM battery couldn't quite cope with the fridge so the battery voltage being available in the MPPT app was really handy. With more capacity in the lithium I imagine we are less likely to run it flat, but I suppose knowing an accurate SOC is important for us.

So, save up for a bit longer and get the 105ah battery AND the Smart Shunt?

I don't think you'll really see a benefit from a heater, in that case. There might be a couple of days a year when you've got solar out and it's too cold to charge but the fact that you've not got permanent solar means they probably won't be very often.

I'd go for the 100Ah drift ECO and the smart shunt. 5Ah is not worth worrying about.

 

[Samiguel]

I don't think you'll really see a benefit from a heater, in that case. There might be a couple of days a year when you've got solar out and it's too cold to charge but the fact that you've not got permanent solar means they probably won't be very often.

I'd go for the 100Ah drift ECO and the smart shunt. 5Ah is not worth worrying about.

Brilliant. Thanks for the advice...

 

[Samiguel]

Brilliant. Thanks for the advice...

Actually just triple checking - low temperature protection prevents the battery from being charged, so the DC-DC charger won't damage it if below freezing?

 

[TallPaul_S]

Actually just triple checking - low temperature protection prevents the battery from being charged, so the DC-DC charger won't damage it if below freezing?

Correct, the battery BMS will stop any charge coming in from actually charging the battery when it's below freezing. You can just leave the chargers to do their thing as normal, the battery BMS will block the charge.

You can still discharge the battery below freezing (so it'll power your fridge etc), that's all fine - but charging a LiFePO4 battery below zero is a big no-no.

 

[NicolasH]

We have the Fogstar Drift 105 and it has been brilliant. So much better than our traditional lead acid leisure battery. Fit and forget.

It can power the fridge, lights, diesel heater and phone chargers for days. It’s combined with a PV Logic 100w panel, PV Logic MPPT charger, Victron Bluesmart 30a charger, and an Ablemail DC to DC.

We had an issue with the battery not reporting the correct SOC to the app. Fogstar support were really good. We just had to charge the battery until it reached 14.2v and it reset the BMS.

Recommended.

 

[Jamesie]

I'm still weighing up the Fogstar Eco over the Drift to replace my AGM. Hope this isn't a daft question but trying to fully understand built in heating on the Fogstar Drift - I have a Victron XS DC-DC (with engine running hardwired to it) and no permanent solar charging. I understand the leisure battery heating function would only draw power from a charging source and doesn't self-consume power. So if the van is parked up and the temperature goes sub-zero, the battery heating won't come on, and will only switch on, powered from the Victron DC-DC when the engine starts? Just confirming there's no way leisure battery heating can switch on and flatten the starter battery when parked up.

 

[TallPaul_S]

I'm still weighing up the Fogstar Eco over the Drift to replace my AGM. Hope this isn't a daft question but trying to fully understand built in heating on the Fogstar Drift - I have a Victron XS DC-DC (with engine running hardwired to it) and no permanent solar charging. I understand the leisure battery heating function would only draw power from a charging source and doesn't self-consume power. So if the van is parked up and the temperature goes sub-zero, the battery heating won't come on, and will only switch on, powered from the Victron DC-DC when the engine starts? Just confirming there's no way leisure battery heating can switch on and flatten the starter battery when parked up.

Correct. If there's a charge current coming into the battery and the temperature is below the cut off, the battery will just limit the current and send it to the heater until it reaches 5 degrees when it'll then allow full charge current to the battery itself.

 

[tomosllyr]

Skimmed through this thread. Lots of useful information, although it has become apparent I need to do more reading.

I have a Victron dc/dc charger, so from what I've understood, there's no reason I can't swab my current lead 110ah (c100) battery for a 100ah lithium one? I understand the Victron settings will need to be changed.

Also, I don't think I have a EHU charger (or I certainly can't find it if I do have one!). To tell for certain is it as easy as having a multimeter on the battery with and without hook up in place?

 

[Jamesie]

Skimmed through this thread. Lots of useful information, although it has become apparent I need to do more reading.

I have a Victron dc/dc charger, so from what I've understood, there's no reason I can't swab my current lead 110ah (c100) battery for a 100ah lithium one? I understand the Victron settings will need to be changed.

Also, I don't think I have a EHU charger (or I certainly can't find it if I do have one!). To tell for certain is it as easy as having a multimeter on the battery with and without hook up in place?

If I were you I'd be happier knowing what is installed and how it's connected and protected. So assuming you have EHU, does this go to a consumer unit with 230V breakers? If so can you identify what is on each of the breakers? Mine has a main incomer breaker then three separate circuits - one for the 230 / 12V battery charger, one for the mains sockets inside the van and one for a hot water heater. You should be able to work out what is what by a process of elimination. The leisure battery volts should in theory rise when a charger is connected to it but may not if the battery is full.

 

[tomosllyr]

Yes it looks like my consumer unit has three circuits. One is labelled sockets, one labelled power supply and one is main isolator. I'll see if I can work out what the power supply one is.

The consumer unit is in the wardrobe and my dc/dc charger is under driver's seat. With the leisure battery. I can't in all honesty imagine where the EHU charger would be if there is one.

I just don't want to fit a lithium battery inappropriately!

 

[tiptoeing1421]

Afternoon

Hoping for some help/clarification, On a previous trip I was fairly certain I drained the current battery lead acid? (Enforcer 110ah 12v) without fully knowing the limitations of the battery type, for a following trip, I quickly added in a Victron Battery Protect to stop it from happening by setting voltage cut off at 12.05V While away, I noticed just how quickly it drained through a fully charged battery with just the fridge running (Campercool CC50).

So I'm now trying to work back from what I have in the van be bought converted, So like others can I upgrade to a LifePO4 battery to give me more usable capapcity and not have as much concern about it draining.

I have taken some photos of the van electrics can be seen here - Van Electric Pics

175w Flexi Solar Panel
Victron MPPT Smartsolar 75 15
Sargent PF200 - Believe this charges when on hookup?
Sargent DX20-12 DC to DC Charger, assume this feeds from Vehicle Battery/Alternator?

From chasing cables, I've started labelling what they are, Aswell as adding in the Isolator switch under Victron MPPT as I wasn't able to shut off solar, I also added another line out to an XT60, so I can also charge my Ecoflow Powerbank. 1= EcoFlow, 2 = Victron, 1&2 (Not used as MPPT will fight each other I believe).

I belive looking at the specs of the Sagent PF200 its max output is 13.8V, so this won't fully charge a LifePO4 but would the DC/DC and/or Solar then finish off the charging in case of EHU? Sargent is quite vague and says, "It is designed to work with lead acid batteries and is also compatible with the latest AGM batteries and many lithium batteries with built-in battery management systems with an input voltage of 13.8V (please refer to the battery manufacturer documentation for compatibility"

I assume DC/DC and Solar wise if I change the charge profile to lithium, that side would be okay?

I'd been looking at Roamer 110ah, although I would prefer maybe 140-160ah to give me more runtime for longer trips so open to suggestions if Lithium is possible? Limitation would be space but I can check dimensions while i have seat off


Thanks in advance

 

[RunDSG]

Afternoon

Hoping for some help/clarification, On a previous trip I was fairly certain I drained the current battery lead acid? (Enforcer 110ah 12v) without fully knowing the limitations of the battery type, for a following trip, I quickly added in a Victron Battery Protect to stop it from happening by setting voltage cut off at 12.05V While away, I noticed just how quickly it drained through a fully charged battery with just the fridge running (Campercool CC50).

So I'm now trying to work back from what I have in the van be bought converted, So like others can I upgrade to a LifePO4 battery to give me more usable capapcity and not have as much concern about it draining.

I have taken some photos of the van electrics can be seen here - Van Electric Pics

175w Flexi Solar Panel
Victron MPPT Smartsolar 75 15
Sargent PF200 - Believe this charges when on hookup?
Sargent DX20-12 DC to DC Charger, assume this feeds from Vehicle Battery/Alternator?

From chasing cables, I've started labelling what they are, Aswell as adding in the Isolator switch under Victron MPPT as I wasn't able to shut off solar, I also added another line out to an XT60, so I can also charge my Ecoflow Powerbank. 1= EcoFlow, 2 = Victron, 1&2 (Not used as MPPT will fight each other I believe).

I belive looking at the specs of the Sagent PF200 its max output is 13.8V, so this won't fully charge a LifePO4 but would the DC/DC and/or Solar then finish off the charging in case of EHU? Sargent is quite vague and says, "It is designed to work with lead acid batteries and is also compatible with the latest AGM batteries and many lithium batteries with built-in battery management systems with an input voltage of 13.8V (please refer to the battery manufacturer documentation for compatibility"

I assume DC/DC and Solar wise if I change the charge profile to lithium, that side would be okay?

I'd been looking at Roamer 110ah, although I would prefer maybe 140-160ah to give me more runtime for longer trips so open to suggestions if Lithium is possible? Limitation would be space but I can check dimensions while i have seat off


Thanks in advance

There’s a lot to comment on here.

My view, in short…
- Go lithium. Go as big as you can reasonably fit and afford. Get one with a BMS. One of the best upgrades I ever did.
- Do some maths, and maybe even use AI to help. ChatGPT gave me some really useful insights. I provided:
- what appliances were drawing from my battery and approximate loads
- the wattage of my panel
- the size of my battery
And then asked:
- considering the amount of sunlight based on time of year, how many days can I be off grid?

Or likewise, if I want to be off grid for this many days, how big is my battery or how big is my solar, or which devices can I run, etc.

Enjoy the research and upgrades.

 

[RoamerBatteries]

Yes 13.8V will still charge a lithium battery to full (eventually) and as you’ve also got the DCDC and solar chargers at higher voltages, it doesn’t really matter anyway.

Where you would normally struggle here is that lower charge voltages and sporadic charging can cause cell balancing issues as it won’t be getting a regular absorption charge. This isn’t an issue with Roamer batteries however - the active balancer works constantly so it is a lot more forgiving of different voltages. You can use pretty much any lead acid charger on a Roamer battery as it long as it doesn’t exceed 14.4V and you turn off any equalisation or desulphation modes.

The 105SMART, 160SMART and 230SEATBASE models all fit under the seat. If it’s a 105 or 160 you have room to spare for chargers too as per the below example (this uses one of the mounting kits from Hythe Auto Electrics, this isn’t necessary it’s just to tidy it up a bit)

 

[tiptoeing1421]

Yes 13.8V will still charge a lithium battery to full (eventually) and as you’ve also got the DCDC and solar chargers at higher voltages, it doesn’t really matter anyway.

Where you would normally struggle here is that lower charge voltages and sporadic charging can cause cell balancing issues as it won’t be getting a regular absorption charge. This isn’t an issue with Roamer batteries however - the active balancer works constantly so it is a lot more forgiving of different voltages. You can use pretty much any lead acid charger on a Roamer battery as it long as it doesn’t exceed 14.4V and you turn off any equalisation or desulphation modes.

The 105SMART, 160SMART and 230SEATBASE models all fit under the seat. If it’s a 105 or 160 you have room to spare for chargers too as per the below example (this uses one of the mounting kits from Hythe Auto Electrics, this isn’t necessary it’s just to tidy it up a bit)

View attachment 301645

Thanks for the response Steve, hadn't realised Roamer had a presence on the forums but really glad you do and took the time to respond - Ordered a 105 for collection as I'm local to your HQ.

Assuming I will not really need Victron Battery Protect moving forward?

Having still been troubleshooting what's going on with the Sargent DX20-12 I'm not convinced it's working but I'll fit the battery and see if I see any incoming load and if not add a Orion TR DC to my list!

Having chased cables and looked over other setups I am concerned some cabling runs seem longer than necessary so I'll address this before I put battery in place

Thanks again

 

[Drive Wayne]

Thanks for the response Steve, hadn't realised Roamer had a presence on the forums but really glad you do and took the time to respond - Ordered a 105 for collection as I'm local to your HQ.

Assuming I will not really need Victron Battery Protect moving forward?

Having still been troubleshooting what's going on with the Sargent DX20-12 I'm not convinced it's working but I'll fit the battery and see if I see any incoming load and if not add a Orion TR DC to my list!

Having chased cables and looked over other setups I am concerned some cabling runs seem longer than necessary so I'll address this before I put battery in place

Thanks again

You won't go wrong with a Roamer, I would say go for a larger capacity if you can, you can never have too much available power. Great company superb aftersales.
The Orion XS50 would be a better choice, again if you can, it runs cooler than the TR30, and is physically smaller.

 

[tiptoeing1421]

You won't go wrong with a Roamer, I would say go for a larger capacity if you can, you can never have too much available power. Great company superb aftersales.
The Orion XS50 would be a better choice, again if you can, it runs cooler than the TR30, and is physically smaller.

Cheers I was tempted by the 160 but knowing I may also then need to replace B2B I may need spare funds towards that!
Also concerned with cable lengths and positioning so the 105 should give me more options, would be nice is a smaller variant comes available in time

We mainly just run fridge and lights off 12v I have an EcoFlow 1kwh Powerstation for anything 240v or when off grid.
I'll lookup XS50 now thanks for suggestion

 

[Drive Wayne]

Cheers I was tempted by the 160 but knowing I may also then need to replace B2B I may need spare funds towards that!
Also concerned with cable lengths and positioning so the 105 should give me more options, would be nice is a smaller variant comes available in time

We mainly just run fridge and lights off 12v I have an EcoFlow 1kwh Powerstation for anything 240v or when off grid.
I'll lookup XS50 now thanks for suggestion

In fairness we now take out a Bluetti AC180 (90Ah) power bank which does the 'heavy lifting' in the awning, leaving my Roamer 230Ah to sit in semi retirement in the van. Saying that it does look after 2 compressor fridges and all the van electrics, wifeys hairdryer and straighteners in the van. XS50 is well worth spending a little more on. A 105 with your Ecoflow should do the job, nicely!

 

[RoamerBatteries]

Thanks for the response Steve, hadn't realised Roamer had a presence on the forums but really glad you do and took the time to respond - Ordered a 105 for collection as I'm local to your HQ.

Assuming I will not really need Victron Battery Protect moving forward?

Having still been troubleshooting what's going on with the Sargent DX20-12 I'm not convinced it's working but I'll fit the battery and see if I see any incoming load and if not add a Orion TR DC to my list!

Having chased cables and looked over other setups I am concerned some cabling runs seem longer than necessary so I'll address this before I put battery in place

Thanks again

The Battery Protect isnt needed but if you've already got it, you could still use it as a Bluetooth switch. I find it quite useful to be able to turn off the 12V fuseboxes on demand

 

[tiptoeing1421]

Just wanted to give a big shout out to @RoamerBatteries Steve for responding and offering advise, and for Chris for getting in contact letting me know the order was available to collect and his time when chatting collecting - Very knowledgeable and top-class customer service and support.
If you're in market for electrics and batteries, look no further, I wish I had known about them and their service, as it would have swayed me to go more down self self-build option with their design service