OK, thanks for that, and thanks for other advice.
Flat lithium battery.
- Thread starter Rustin
- Start date
I agree, but, this is NOT the first time I see it on budget bms. Even bigger brands, the software quality control is atrocious. So I got used to their mistakes.
Has your charger got a lithium charging setting? if not, only 70% to 80% charge before shut off.
Hi there,
Thanks for your reply, and thanks to all who answered.
My Victron is an MPPT 75/15.
Re the advice to put the battery through a few cycles - how do I do that, please?
The app has continued to not work, so I am completely unable to monitor anything.
The app get a terrible score (2.8) on Google Play, so I am beginning to think the whole system is not fit for purpose.
I'll consider purchasing a Victron Shunt, but begrudge spending the extra money.
I also notice that the manual for the battery can not be downloaded, both on app and website.
The dip switch settings on the 12v Nordelettronica charger unit were set for Lithium.
Any advice on discharging the battery without a working app, guys?
TIA. Mike.
What do you mean by the "app has continued not to work" ?
You have posted screen shots of the app so the app itself must be working
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The first thing I would do is get on hookup and use a multimeter to measure what voltage you are getting at the battery terminals, remember that the primary task of the BMS is to protect the battery from over and under charging, the app should really only be considered a guide and as has been said will take a few cycles to calibrate itself. Quite a few of us now have Fogstar batteries and are very happy with them, once it's been cycled a few times it should all settle down and be quietly doing its job. Let us know what voltage you are getting at the battery terminals with a multimeter once on charge and maybe we can advise further.
Fogstar manual attached.
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It will be very difficult to gage 70-80% SOC on lifepo4 by voltage almost impossible, as is still in the flat curve of the cycle. Also when battery reaches 13.8v its almost 95-99% charged. Give it 14v and its full. The 14.4v is only valid if your charge rate is minimum 0.2C rate, 20A for every 100ah.
A lower charge rate will have a lower termination voltage.
Voltage as indicator of SOC is only valid when nearly empty or nearly full, not at 70-80%
This is the app currently. 0 on capacity, 0 current, 11.2v, I believe all are incorrect.
This morning with 0.0 capacity we had lights, heating and could raise the electric bed.
Thanks for all of that, don't have a meter with me ,if I don't get one beforehand I'll crack on with that upon my return next week.
What charge source do you have connected ?
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I think given you are away I would just use it - Victron Connect and your Solar controller will give you a voltage, so I would just run the battery down with whatever loads you can, or want to use, and when it gets to 13.0v shown on your solar with the panels disabled (when its dark - plug in the EHU charger, untill it hits 14.somethingv - If after a few full cycles like that, its still not right I would ask Fogstar to swap it.
Doubt it will make any difference, but there are other apps that work with the Fogstar BMS, someone on here will know, perhaps there is a way to clear/reset the BMS. Sorry I'm not very familiar with Fogstar and the various apps.
Just remembered the Renogy charger should show green led when it thinks the battery is full, 14.5v IIRC. That would be fine.
Were you on EHU ?
Right now I'm on ehu.
Not then I wasn't. We were unplugged overnight, using battery only, using lights, TV, heating. Had heating on low overnight. In the morning we had breakfast using lights and heating, then we raised the electric bed, then I plugged into the mains.
When we went out this morning, the Adria panel was showing 23% capacity (for what that's worth), when we returned late afternoon, after a lovely sunny day, it was up to 73%. But during this evening, despite being plugged in, it has drained to zero.
The most frustrating thing is the non working app. It worked before we left home on this little trip to Broadway, since we got on site the app hasn't worked, so I have zero knowledge of what's happening.
That 11.2v is dangerously low with loads. For reference divided by 4 cells = 2.8v per cell. You should never need to go below 3v per cell, (12) from here is less than 5% capacity left. Spend a couple of days on ehu, and give that battery time to absorb. It looks like you are working in heavy deficit and weak means of charging.
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MichaelT
LIFE MEMBER
Try uninstall and reboot phone the install again.Not then I wasn't. We were unplugged overnight, using battery only, using lights, TV, heating. Had heating on low overnight. In the morning we had breakfast using lights and heating, then we raised the electric bed, then I plugged into the mains.
When we went out this morning, the Adria panel was showing 23% capacity (for what that's worth), when we returned late afternoon, after a lovely sunny day, it was up to 73%. But during this evening, despite being plugged in, it has drained to zero.
The most frustrating thing is the non working app. It worked before we left home on this little trip to Broadway, since we got on site the app hasn't worked, so I have zero knowledge of what's happening.
Morning all. Well, latest bit of the saga, this morning the vehicle battery was low and I've had to jump start the vehicle. I think it's suffice to say that my vehicle electrics are completely up the shute and there is something very wrong somewhere. We're cutting our stay short and going home, I've got the van booked in with my electrician tomorrow.
The app is showing the Fogstar battery is charging from the engine, so maybe the app is OK. Something completely depleted the Fogstar on our first night, and after that it hasn't charged from either solar or the mains.
I'll report back any findings. Thanks for your help guys.
The app is showing the Fogstar battery is charging from the engine, so maybe the app is OK. Something completely depleted the Fogstar on our first night, and after that it hasn't charged from either solar or the mains.
I'll report back any findings. Thanks for your help guys.
I too think the app is ok, despite its shortcoming of accuracy, from your posts, to me you are consuming more than you can charge, and battery ends up low all the time.
Having an electrician looking at it is best approach now. You may need the EHU charging looking into, and maybe loads that not suppose to be there.
CAB96
LIFE MEMBER
If the Fogstar was effectively empty and /or off, could you have been using the vehicle battery? And that's why it was flat?
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After reading this thread about your Fogstar battery a couple of thoughts came to mind. Do you have your charger set up to trickle charge the vehicle battery and if so could this have been draining your leisure battery due to starter battery being faulty? Secondly on our 300a Fogstar pro when on hook up the victron multi plus puts our battery on storage at lower charge and then occasionally tops it up to full to prevent damage to battery.
We now have 26 cycles on it and it is currently holding at 61%
We now have 26 cycles on it and it is currently holding at 61%
slightly aside of this, my fogstar (280ah) app showed SOC 260ah but combined cell voltages of 12.4. had V of 13.5 two days previously. On charge (victron 30 a) slow rise to 13.2v and SOC 98%. drop to 12.7v after 6 hrs 2A draw. is this just BMS (still on cycle 1) or more sinister. Battery not been used much as just installed Oct. little discharge. Is long bulk charge and full discharge the way to go? Ta and bw
Nothing sinister and normal behavior of a bms. The way it will trigger 100% SOC, is either by cell voltage or pack voltage set in the software, it could be 14.2-14.4v pack, or 3.55v-3.6v per cell.
Get it full to reset to true 100% and expect to drift as you discharge it. If you want to know real capacity left, fit a shunt.
There are many ways to know the charge in your batteries.
I remain doubtful about the use of the shunt. I understand that it measures flows very precisely but the round trip efficiency of the battery is unlikely to exceed 93% and battery capacity reduces with temperature as anyone with an EV knows.
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Yes there are quite a few variables that affect the measurement/performance of a battery system and the monitoring system.
I find that the shunt is pretty accurate, and don't compare it to a battery BMS, or anything else.
But when I am using the van, I dont need to know if I am at 62% or 65%, I just need to know broadly where I am, and since the shunt doesn't drift much in-between full charges it does the job, and is easy to install.
Given we use lithium Voltage is not a good enough indicator.
I find that the shunt is pretty accurate, and don't compare it to a battery BMS, or anything else.
But when I am using the van, I dont need to know if I am at 62% or 65%, I just need to know broadly where I am, and since the shunt doesn't drift much in-between full charges it does the job, and is easy to install.
Given we use lithium Voltage is not a good enough indicator.
The round trip efficiency of a lipepo4 is 95% or much higher. Charging efficiency is 99% at least when new, ( almost 100%) and it may drop to 98% after few years of use. Then, when it comes to discharging the peukert exponent setting takes care of that. Somebody did all the calcs for us, put in a nice pcb, and a microprocessor does the job, taking in consideration the charge-discharge rate, giving us a almost true value of what is going in or out. The shunt by itself will not be able to calculate the inefficiencies, it will count 1:1 in-out, but the pcb is the add on calcs that makes the shunt versatile to set/adapt in various systems with various inefficiencies. You just need to set those values right, that mirrors your system efficiencies. Not all are the same.
It might be worth remembering that not all battery monitor shunts are equal. When I bought mine Victron was the only one that had proper settings that could be adjusted to LiFePO4 batteries. In particular none of the other ones such as NASA had peukert settings which are very different for Li batteries. There may have been improvements to other makes over the years but best to make sure before buying.
Yes, low temperature cut off charging.
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