arthur49

Smart BMS App for Daly BMS My app updated automatically to v2.4.0 on 23 Dec. I now can't connect to my batteries! Version includes an update to BMS firmware which fortunately I did not attempt as reading reviews it basically appears to disable the BMS! So if you have Smart BMS suggest you don't update app and certainly don't attempt firmware update until fix has been applied. Check reviews on PlayStore

I attach screenshots of settings I use based on the recommendations by Mikefitz and Veletron earlier in this thread. You will note the Diff Volt of 0.36v on one of my 100Ah Sterling lithiums - 18 months old. This figure does reduce but I've never witnessed it below 0.26v. (The other battery Diff Volt is sitting at 0.003v as I write) So I am currently in discussion with Sterling-Power who are asking lots of questions. To me this battery is faulty and should be replaced.

Yes, I got caught out once when BMS shut batteries down and I decided SOC on BMS is so inaccurate its unhelpful so I've followed your solution and will count Ah ! I now have a Victron Smart Shunt 500A (though I never draw more than 85A). From 12v Planet which with loyalty points cost me only £103, and dead easy to install and configure. "Tail current" setting is default 4% (8A) but some users say 2% so it may be trial and error to find best setting. Question - my MPPT solar regulator is Votronic set to lithium. 120W panel. Do you leave it connected to batteries when "storing" van for a few weeks with batteries at 50% SOC approx, or do you pull the fuse?

Yes, thats the one I use from here :-D https://diysolarforum.com/threads/lifepo4-voltage-chart.3156/

Thank you. I tend to use voltage as an indicator of SOC. When it drops to lower than 13.1v we take care :-D

State of Charge (SOC) Just thought I'd post re SOC of my two Sterling Power LiFePO4 batteries. Van in drive for 10 days now. I "store" van with batteries roughly 50% charged. We know BMS measurement of SOC is very rough but with both batteries sitting at 13.1v according to BMS the SOC's are showing as 66% and 85% I reckon 13.1v is 40-50% so SOC on both batteries is miles out. 8-)

Karen were you aware NASA Marine have a lithium version now https://www.nasamarine.com/product/clipper-bm-1-lithium-lifepo4-battery-monitor/ But looking at instructions it looks like state of charge / sync will never be correct and can't be set as fully charged voltage will never reach 14.4v?

"..........all of a sudden with lithium the lights just go out and the only way to get em back on again it to supply some charge!" Exactly what happened to us as we were having breakfast last week - I wasn't paying enough attention to discharge/charge and the batteries died! Thank you Karen. Your input and that of Mike is really appreciated :-D

I'm finding getting the last 10% of charge into these batteries is a challenge. Using the Votronic 25A mains charger, on continuously for 3 days should have done the trick? Charging profile for LiFePO4: U1=14.40 V 0.3-1 h U2=13.80 V 24 h U3=13.45 V Continuous When I switched off charger after a couple of hours BMS was showing batteries at 13.4v (100%) One day later, with no charge or load, its fallen back to 13.3v (90%) ? And 3 days later still sitting at 13.3V.

Thank you Mike. That could explain it - Sterling couldn't. It was cold, we had not driven far since previous night so batteries did not get a full charge

That is very cheap. I can't see that it has a wake up function for a BMS shutdown? Having said that my Votronic 30A (£178) could not wake up the BMS at the weekend despite the fact it has, supposedly, that function - died when drawing 80A/40A per battery with voltage on app showing 11.8v under that load. None of settings were wrong. Set to cut out at 10.8v and Sterling don't know why, but got it going again with mains charger! Sterlings 30A is £435???

I've tried to present ideal voltages/current to the BMS and using it as the last resort/refinement B2B max voltage 14.4 max current 30A. Mains charger 14.4v / 25A. Solar 120w 14.4v / 15A

Thank you Karen. For all the large power cables I followed your example and and used 4AWG cable. Looking at the mains charger yes the fuse on reflection is poor. Cabling is 70A from charger to batteries but its a 30A fuse in a car blade type holder rated also 30A, so I suppose I should expect heat! I have a midi strip/link fuseholder with M5 studs in my spares, I'll use that with 40A fuse I think. Fuses to/from B2B and alternator and batteries, all 4AWG cable, are mega link with M8 studs and cable run to B2B is a little over 2m. I do plan to change the fuses from batteries to cube type but laziness set in Thank you for your help again

Sorry another question! Mains charger is Votronic 25A with lithium setting. Its approx 30cm from batteries so short cable. I used 70A interconnect cable as that is the same as rest of van. Fuse is 30A, fuseholder rated at 30A. BMS says batteries are receiving 24.5A. All contacts are clean and secure. Cable is only very slightly warm but fuseholder/fuse is fairly hot to the touch. Is this normal or should I beef up fuseholder and fuse?

Mike - for info I love these batteries and I've found Sterling Power very good if you contact them for help but you're right quality control is not great. Just found that low temp discharge was set at 0 degrees so I've reset to -20 degrees. And I didn't realise that starting the engine wakened the BMS as it wasn't in instructions When the batteries arrived 6 months ago the settings were different on each! Every day's a school day even at 70+ KAREN - this is your thread and I don't want to take it over but we have identical batteries!

Thank you Mike. I took the batteries out and left them in kitchen. Within a couple of hours temp was showing 13 degrees, voltage 13.1v. Put back in van - not a hassle really as they are light - and everything working great. Thanks again Mike. I had a horrible feeling something was wrong but BMS was only doing its job

Intending to go away in van in a few days so thought I'd check all OK. No 12v at control panel. All fuses appear OK. Its cold here - frost overnight - so took lithiums out into house after finding no 12v at panel. According to app voltages are approx 13.1v on each and approx 86% charge. Putting a meter on the terminals gives reading of 9.48v on one and 9.47v on the other. BMS temps set at 0 degrees charge and discharge. The charge and discharge sliders show not activated. I take it this is the BMS doing its job and disabling charge/discharge? (though temp is +2 degrees)

Thank you for posting this Karen. I found balancing did kick in but seemed later than I would have expected. My protection parameters are the same as yours. I've now changed the coil characteristics to yours. Am I right in thinking Balanced Open Start Voltage is the figure at which balancing will start if any cell is at that level, or lower? And Balanced Open Diff Voltage is obvious I think? This was sitting at 0.03v now changed to 0.01v Love these batteries by the way.

Thank you Karen

Thank you Mike. The B2B, solar regulator and mains charger all have a lithium setting and the temp sensors are to monitor the low and high temps and therefore regulate/terminate the charge should such temps be encountered. The mains charger (Victron) in fact will not operate on a lithium setting without temp sensor being fitted. Whilst the battery BMS monitor and adjust temp, charge etc etc, I've taken the view the BMS should be the "fall back" and as much as possible the B2B, solar, mains charger should take a primary role in presenting the batteries with ideal volts/current? (With apologies to Veletron/Karen, I'm not usurping this thread but we have identical lithiums!)

Thank you Karen. Most of my wiring is commoned on busbars, though the inverter is taken directly off the batteries. I've used 4awg cable between batteries and busbars. The inverter comes with 4awg cable (Sterling 1800w). I'll alter inverter cabling to meet at busbars. How have you fitted temp sensors? They are supposed to be direct on negative post. I have 3 to accommodate - B2B, mains charger and solar regulator. Could I put these on busbar too? Arthur PS a lot of the cabling in my van came in convoluted conduit and I've continued that practice, but it does look untidy compared to yours, so no photos from me :-S :-S

Thank you Mike

Thank you for update. Don't want to usurp your thread but we've just had 2 weeks away with our two Sterling lithiums and we are delighted with charging etc :-D Question: the battery terminal studs are short, with plain washer and a locking washer. Because these studs are relatively short I find it difficult to get all the accessory leads connected! For example, the mains charger, solar controller and B2B all have temp sensors connected to negative. These can be shared between the two batteries but there are other accessories to accommodate - voltage sensor for B2B, mifi charger, inverter etc Do you find it a fiddle to accommodate everything on the studs? Do you remove the washers to create more space, or maybe longer studs are available?

Thank you Karen I'll alter mine to 3v as well :-D :-D

Thank you for this Karen. I went ahead and installed 2 of these as well. They've not been tested in use yet, but I noticed on delivery that Cell low cut off was not the same; Battery 1 - 2.75v Battery 2 - 2.00v Big difference. After speaking to Sterling I altered these to 2.5v. I have a Schaudt 45A B2B and a Votronic 25A mains charger, both set to lithium (14.4v). At 70% SOC (and checked separately!) I'm getting 13.7v at batteries, not 14.4V. If I pull the output fuse the voltage at mains charger rises to 14.4v so I suspect the CBE DS520AN Distribution Box is pulling the volts down, so I'll try mains charger connected directly to batteries to check. My B2B is in the supply between starter and Distribution Box and worked great with LA batteries, but only 13.7v at lithium batteries? In both cases though the charge current is to spec and batteries charge to 100% SOC FAST according to app!