What I suspect you are going to find trying to actually do a full cycle is a wish you'd moved away from AGM sooner 
Swapping my leisure battery to LiFePO4
- Thread starter Salty Spuds
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So made it to 3pm today when it reached 20% with fridge and all lights on. About 42 hours. Yes this does make me wonder why I didn't do it before!
Now recharging at half power which will reach 100% in the middle of the night (I'm not getting up to turn it off). Don't know how to play the remaining time - assuming we go away lunchtime Monday and don't have hookup, we will have about 26 hours to drain and recharge (reckon we will drive about 90mins so doubt much charge from that).
Can I also ask what the on/off switches in the app do for charge/discharge. E. G. does switching discharge to off isolate the battery?
Now recharging at half power which will reach 100% in the middle of the night (I'm not getting up to turn it off). Don't know how to play the remaining time - assuming we go away lunchtime Monday and don't have hookup, we will have about 26 hours to drain and recharge (reckon we will drive about 90mins so doubt much charge from that).
Can I also ask what the on/off switches in the app do for charge/discharge. E. G. does switching discharge to off isolate the battery?
Yep you can basically use the BMS (via the app) to isolate it if you want to put it into storage.
Your CTEK should charge at 20Amp so a 90 minute drive theoretically could put in 30Ah, but real world will be a little less.
I'd just leave it on charge till you go away - the value is going through a full cycle.
But don't worry too much, enjoy the break and put it through a couple of cycles when you get back.
Your CTEK should charge at 20Amp so a 90 minute drive theoretically could put in 30Ah, but real world will be a little less.
I'd just leave it on charge till you go away - the value is going through a full cycle.
But don't worry too much, enjoy the break and put it through a couple of cycles when you get back.
Did someone say there is a proper way to switch off the victron ip22 so that we could be on hookup for 240v but without battery charging? That is other than pulling the fuse between the ip22 and the battery.
I looked in the settings but couldn't see anything.
This is what it looks like so far:
I was hoping that fuse could angle downwards but the terminal is too far from the edge to allow it (I know I could work something with a busbar but don't really want more exposed metal).
I think the temporary solution to isolating the battery from anything stored under here might have to be:
But the longer term might just be a surround fashioned out of hardboard unless I can find a cover which will go over that fuse and yet fit in the space.
I looked in the settings but couldn't see anything.
This is what it looks like so far:
I was hoping that fuse could angle downwards but the terminal is too far from the edge to allow it (I know I could work something with a busbar but don't really want more exposed metal).
I think the temporary solution to isolating the battery from anything stored under here might have to be:
But the longer term might just be a surround fashioned out of hardboard unless I can find a cover which will go over that fuse and yet fit in the space.
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Mine is plugged into a domestic single switched skt fed from the hook up fuseboard but I've used this just the once as driving and solar keep the battery topped up.
Not sure if the charger is even plugged in currently but it all sits on the side of the fridge housing behind the drivers seat, Victron charger, 13A skt, 2kw inverter with the Roamer under the drivers seat, nice short cable runs.
As I said the inverter is now a 2 KW so recessed slightly into the fridge housing as it's a bit of a beast but it all fits and you can still slide the seat about.
That's an average sunny day input with the fridge running.
Before anyone asks there's the angle strap that stops the battery moving.
Not sure if the charger is even plugged in currently but it all sits on the side of the fridge housing behind the drivers seat, Victron charger, 13A skt, 2kw inverter with the Roamer under the drivers seat, nice short cable runs.
As I said the inverter is now a 2 KW so recessed slightly into the fridge housing as it's a bit of a beast but it all fits and you can still slide the seat about.
That's an average sunny day input with the fridge running.
Before anyone asks there's the angle strap that stops the battery moving.
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Can I just check something. We are away with hookup available but don't really want to spoil my test of how long the battery lasts and I need to power some 240v appliances for a bit If I want to stop the victron ip22 charging when I plug into the hookup I could pull the fuse between the ip22 and the battery (but it's currently a bit inaccessible.
Could I just switch off the lights/charger/trip on the left hand side of the mains unit? Presumably this only has the ip22 on it?
Could I just switch off the lights/charger/trip on the left hand side of the mains unit? Presumably this only has the ip22 on it?
Yes, just flip the left side breaker, that'll turn off the power to the Victron. You'll still have the 240v sockets running off hookup though.
Once you've done this you shouldn't be able to see the Victron in the app as it won't have power.
Once you've done this you shouldn't be able to see the Victron in the app as it won't have power.
That lefthand double pole trip shows lights, charger, fridge so I'm guessing you'll lose the fridge?
You don't really need double pole trips so you could swap out the copper busbar in the consumer unit add a neutral bar and turn the consumers unit back into a normal single pole 4 way consumer unit and split up the left hand circuits with an MCB for each separate item, you wouldn't normally have lights sharing power with a fridge or a battery charger.
You don't really need double pole trips so you could swap out the copper busbar in the consumer unit add a neutral bar and turn the consumers unit back into a normal single pole 4 way consumer unit and split up the left hand circuits with an MCB for each separate item, you wouldn't normally have lights sharing power with a fridge or a battery charger.
That would only be an issue with a 240v fridge - to my knowledge of helping @wallport over a couple of threads the fridge and lights are 12v only.
I suspect the original labeller may have been trying to help by suggesting if you are using the lights and the fridge on hookup you want that breaker on as they are indirectly powered via the 240v charger.
I suspect the original labeller may have been trying to help by suggesting if you are using the lights and the fridge on hookup you want that breaker on as they are indirectly powered via the 240v charger.
@roadtripper I'm normally off on a tangent and had assumed the fridge was 12 volt but powered by a charger similar to the setup I had with my Sargent ec160 panel.
I did reply earlier in the thread about being able to isolate the IP22 charger and assumed that the fridge was fed directly from the leisure battery so it still works when the vehicle is moving unlike the other leisure circuits which are meant to be off with the vehicle in motion.
It does seem a bit wasteful though to use those DP mcbs in such a small consumers unit as effectively it's just a 2 way unit now, at this point I've probably got the wrong end of the stick again.
I did reply earlier in the thread about being able to isolate the IP22 charger and assumed that the fridge was fed directly from the leisure battery so it still works when the vehicle is moving unlike the other leisure circuits which are meant to be off with the vehicle in motion.
It does seem a bit wasteful though to use those DP mcbs in such a small consumers unit as effectively it's just a 2 way unit now, at this point I've probably got the wrong end of the stick again.
Thanks all. It has all worked exactly as per advice. Turning off the 240v to the victron worked so no charging. Fridge is powered off 12v as per @roadtripper. Battery after about 26:hours is at 79% but only been running fridge, lights and some usb phone charging off it.
Btw air fryer mentioned earlier is working l fine without tripping anything but then hookup here is16a.
Btw air fryer mentioned earlier is working l fine without tripping anything but then hookup here is16a.
For those who remember my attempts to trace what was discharging my previous lead acid battery:
This is after a week without any charging. It's a different world! Driving is usually the only charging necessary and I tend to leave the charger off when on hookup.
Anyone thinking of going lifepo4 - just do it.
This is after a week without any charging. It's a different world! Driving is usually the only charging necessary and I tend to leave the charger off when on hookup.
Anyone thinking of going lifepo4 - just do it.
That's it, I'm going to do it, hang on I did do it, problem now is finding a site that has bogs and showers, allows awnings but doesn't then automatically include an hook up.
Just be aware that the Fogstar BMS can't see any draw under 1a so if you've got something small running constantly there battery BMS won't be accurate. Only a shunt will show the true state of charge.
I've got a Cerbo GX and a 4g router which use about 0.5a, this is the battery BMS Vs the accurate shunt:
You could just turn off discharging anyway on the Fogstar and you'd not have to worry about anything drawing from the battery!
Hah - should have learnt by now that nothing you see can be believed where batteries are concerned!
So, without putting in a shunt, how does one tell the status. Will charging it tell me the amount which went in and thus allow me to work out the amount it was depleted?
BTW, I recently asked Fogstar why the detailed screens in the BMS showed over 100% when the main screen showed 100% and they told me how to recalibrate by completely discharging. I presume this would be a waste of time as it will go out of calibration due to this issue anyway?
So, without putting in a shunt, how does one tell the status. Will charging it tell me the amount which went in and thus allow me to work out the amount it was depleted?
BTW, I recently asked Fogstar why the detailed screens in the BMS showed over 100% when the main screen showed 100% and they told me how to recalibrate by completely discharging. I presume this would be a waste of time as it will go out of calibration due to this issue anyway?
Bung a shunt in with a remote display, as long as the leisure battery is one side of the shunt and all the other negatives including any connected to the vehicle bodywork are on the other side then you'll have an accurate indication of what's in the tank and on my Renogy shunt what's coming in from the solar and how long to empty at the present current draw.
I can't get my head around apps or the blizzard of information they can supply but an app can deceive you compared to the fuel guage reading from the shunt.
I didn't really have 414 Ah left in my 230Ah Roamer, at the same time the shunt said probably 180Ah from memory.
I can't get my head around apps or the blizzard of information they can supply but an app can deceive you compared to the fuel guage reading from the shunt.
I didn't really have 414 Ah left in my 230Ah Roamer, at the same time the shunt said probably 180Ah from memory.
Fogstar could have put in a more accurate BMS but then that would have increased the price.
Tbh, you may not need to worry about the status if you're only off grid for a day or 2.
I had a couple of days on a site at the weekend and used 34Ah in a 24hr period, with 12Ah (0.5a for 24hrs) being my 4g router and Cerbo GX. So 22Ah for fridge, lights, phone charging and an hour of heater use.
If you really want to know your exact state of charge, a shunt is the only (proper) way. You can get one with just Bluetooth so you'd check via the app on your phone, or with a small display.
Or (not recommended or needed!), you can go all in, like I have, with the Cerbo GX, Victron VRM 24/7 monitoring, from anywhere with a 4g signal... Oh and a touch screen display to come
I don't disagree but I think one has to draw a line somewhere with spending on this.
I still don't get what the BMS will show after charging and how calibration works with small discharges. So if I drive (with charging via the d250se) for say 2 hours and the BMS shows 100% when I start, will it show 100% when I arrive - regardless of the real state of charge?
Yes I realise I could put the battery in off mode via the BMS (which I will do in the winter) but I first want to understand how much of an issue this is. I'd rather understand it and (hopefully) be able to ignore it).
I'm a firm believer in KISS and have a basic £60 Renogy shunt to tell me exactly what's in the leisure battery and a 300A rotary isolator on the battery that isolates the battery from the combination of incoming and outgoings fuses.
Theoretically, yes.
If the battery was at 100% then you had a draw of less than 1a, the battery will be at less than 100% but the BMS won't have detected any draw.
So then if you drive and charge the battery back up to a true 100%, it'll show 100%.
I've found mine would sit at 97% when the battery BMS was 30% out - the true soc was about 80% having put 30% back in, but the battery BMS started at 90%.
The fogstar BMS is a shunt, much like a Victron shunt, just not as accurate.
If you don't have anything small running constantly, and only have stuff like a fridge, lights etc that are over 1a, I wouldn't worry about it.
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