Trying to understand/figure out how to avoid overcharging of LiFePo4 batteries. If the charging profile is left at the default profile, and the vehicle is occasionally stopped and started on a undetermined schedule, so that the charging profile begins over again every time, how does the smart charger prevent overcharging? As I recall every time the charger loses the input voltage, the charging algorithm begins again with bulk charging. Could this lead to overcharging the lithium batteries (also in parallel)?
Questions and Answers
My CCGX and Qautro 8000 software was upgraded in Jan 2020. System was installed in Sept 2016 and worked with no problem up to Jan 2020 before software upgrade.
Under Mains failure when Qautro AC input is supplied from SMA 5000TL, the Quatro charging voltage reach 64V DC and it then seems if the system goes into over voltage protection and shuts down. After a minute or so the system starts up and the cycle repeats it self until the mains are restored. This over charging does not happen when AC is supplied from mains. I already lsot one battery due to this over charging and the techs can't assist me!
Usecase: REC ABMS connected to 12x 272Ah cells (Lishen), 3 parallel and 4 series (12V). Charging with 2x Blue Smart IP22 30A, Smart Solar 75/15 and TS800C-50.
The manual of the Blue smart IP22 is very limited with respect to its behavior of the "Lion" setting. First it doesn't feel right they call it "Lion" while LiFePo4 is a total different chemistry, but as they put LiFePo4 between () I assume this mode is for LiFePo4. Anyone that can confirm this?
Can someone explain how the charger behaves in the "Lion" mode?
I want to parallel two of these chargers. Is this going to cause any problems? Do I need to use the "Lion" mode or is it better to use the power-supply mode when putting in parallel?
From what I understood (e.g. https://marinehowto.com/lifepo4-batteries-on-boats/) LiFePo4 is very sensitive to overcharging. Even with low voltages (~13,5V) the battery can be killed when current is applied after 100% SoC is reached (very low internal R). So it is very important to stop charging when the current does reach a certain threshold (ideally SoC based), or to control this externally using a BMS. Anyone that can comment on this?
I have a MP100/30 charger. It's set up to charge a LifePO4 battery and despite my charge profile settings (absorption 14.2, float 13.5, absorption duration fixed at zero minutes), I'm seeing 15 volts plus in the history screen every day. Even when the trailer is sitting in the rain on an overcast day. The only thing running is a small 130l compressor fridge. Worried about damaging my 200ah new battery. Any ideas would be appreciated. Images of the settings and history below. Cheers. Stephan
We have a Victron charging our 3 x 180ah 12v house batteries on our boat. The batteries were new this summer. We liveaboard and have been connected to shore power for 6 weeks. I noticed today the house batteries are being held at high voltage, there are only 1 or 2amps flowing in but the voltage is moving in a range of 14.8 to 15.1v. The multicontrol shows its in absorption phase. After switching off the charger voltage dropped down to 13.4. I left the charger off for 30 mins, it is now back on and holding the batteries between 14.5 and 14.7v, bulk and absorption lights are on, but steady, it's not equalising or forced absorption.
Anybody any ideas where I look, I hope it's not time for a new unit.
I have a 200Ah lithium battery bank connected to my starter battery/alternator via a Cyrix-Li Charge 230A controlled by the BMV 712-Smart.
It's currently configured to only connect when the starter battery is over 14.1V (indicating that the engine is on) and to cut off when the starter drops below 13.7 (when the engine turns off). I'd like to add another condition that my lithium battery bank must be below 95% to protect against overcharging. Not having luck with the state of charge. Anyone have guidance?
ENGINE ON, BANK < 95% = Closed Circuit (aka charging)
ENGINE ON, BANK > 95% = Open Circuit (aka not charging)
ENGINE OFF, BANK < 95% = Open (aka not charging)
ENGINE OFF, BANK > 95% = Open (aka not charging)
MPPT 75/15 overcharging
It was working all fine for 3+ months but then I saw that it charges the battery in 16v+ range. Few days before that I used the same controller to charge another battery and then switched back to the main battery. I don’t know if that triggered some problems because it was cloudy on those days.
But now, if it’s sunny, it goes to 16v range and always stays in a BULK mode (flashing fast), never going into Absorbtion or Float. I tried disconnecting everything and connecting to another Victron battery and the same thing, as if the charger thinks that the batteries are 24v, but they are 12v. Could that be a problem? I don’t have a dongle to check it out, can’t buy one because shops are closed. Is there anything else I can do to find the cause of the problem or temporarly fix it?
My set up:
2x 120w solar panels connected in series.
As I said before, it was working perfectly for few months and then suddenly the problem occured. Currently my solution is to disconnect the panels if its a sunny day, but my campervan fridge drains it quite fast. I tried partially covering the panels but strong wind blows anything off the roof…
Thanks for help.
We had our system checked and the VE engineer set the ABS to 14.70 and the Float to 13.8.
However, the batteries have been charging at 15.75v and they're now cooked. How could this happen? He has sent me a screenshot to show the settings so I don't think he's done anything wrong. The batteries are: VE AGM supercycle 125a x 6.
Hi guys and girls!
We have an issue. TLDR: skip to the bold text ;-)
Please see these and read the explanation;
Besides this, there is a 48V battery bank as well, consisting of three strings.
You can see their connections coming down into the box as the orange (and black) cables connecting to the shunt and the bus bar.
A quick explanation;
We are on a truck!
All equipment is brand new, including the batteries.
The batteries have been balanced by means of charging each of them fully with the same 12V charger before connecting them in strings.
Each Quattro has its own Color Control.
There is a BMV702 connected to the first Color Control (in order to have its data logged to the VRM portal) and the BMV702 is setup with midpoint monitoring.
The truck is connected to grid with a 32A CEE connector.
The Quattroes does not "see" each other - this is NOT a 3 phase system.
The reason for that is that we have loads of redundant technical equipment on Quattro 1 and 2 and cooling on number 3. In case a Quattro fails a 3 phase setup would make them all shut down, where we with this setup can keep running on the remaining power.
We have a similar setup in two other trucks where the only difference is that the system is 12V and with smaller Quattros. Has been running for years without any issues :-)
The Quattros in this system is set with Victron GEL/AGM-batteries as battery type and all the batteries are 12V GEL Deep Discharge 220 Ah.
Charging is set to max 40A per Quattro, but setting the charge current as low as 10A doesn't solve the below issue.
Now, to the problem;
If I discharge the batteries by 5%, 10%, 15% - it doesn't really matter - and then reconnect grid power, bulk charge will start. When bulk ends, absorption starts and what the hell happens!?
We don't understand it.
The distributor don't understand it.
We've tried rearranging the batteries - we've tried everything.
My quess is some kind of over charge; ie. the Quattros sensing the charge state wrong?
Needless to say, batteries on one side of the bank was boiling.
Absorption voltage is 57.60 V.
When the Quattros goes from Absorbtion to Float, batteries will settle and balance within a relatively short period of time.
There are no battery balancers connected.
I have a 250 Wp solar panel on the roof of my work van, which is connected with an MPPT 75-15 to the starter battery of this vehicle.
The battery is only 1 year old, but is playing up (sometimes doesn't have enough power to crank the engine). This battery died very fast, so I started investigating.
But now I see that the MPPT is actually sending up to 17 volt to the battery when charging in sunny conditions. I can now imagine why my battery is broken already. Is seems it has been systematically overcharged.
Any ideas how this can happen? Is this MPPT broken? Or could there be another reason why this high voltage is happening?
Also see screenshots below.
Happens when panels are parallel or series. Ambient temp is about 25C.
Connected to an AGM battery which starts to boil as soon as voltage goes over 14.4
If 2nd panel is disconnected, voltage will not drop. Both panels have to be disconnected to reset and then when one panel is again connected it goes to normal bulk voltage.
I have voltage of (18-20 volts depending on the sun) that goes through to my 12 volt electronics in the camper. I have NO inverter. Have a 200 watt panel on top, wired to a BlueSolar mppt 100/30-shunt-BMV 712-BattleBorn 100amp Lithium. The system works great until the BattleBorn is charged, then the voltage keeps climbing up. I have tried numerous resets and disconnected wires, have the mppt rotary dial set to #7, what should I do next or redo...lol? On the bluetooth app I can't find a 12v or 24v system setting. Oh the mppt stays in bulk after the battery is charged...tx...Tom
We have two VE Multiplus 3000 connected in parallel, and 6 x VE AGM supercycle 125 batteries which are a year old. We had a VE engineer check out the set up one month ago and he did a diagnostic with his laptop. He changed the ABS to 14.7V and float to 13.8. However, our batteries are not holding charge now and the electrician here in Italy said that 5 are dead. He then connected them up and measured the voltage going in from shore power which was up to 15.75 v.
Could the recommended VE engineer have set something incorrectly, or is one or both of the multiplus 3000 units damaged somehow?
Everything seemed fine before he changed the settings, but he seemed to know what he was doing! I don't want to destroy a new set of batteries.
Concerning a marine 12VDC system: Which product can do a high voltage battery disconnect that I can program/set the volts at? I'm aware of the BMV-712 relay control function, but already have a battery monitor system in place, and regardless I would also then need a high amperage relay. Is there an all in one product like BP Battery Protect, but used to disconnect any over-charging conditions for my charge bus and possibly with alarms too?
We have this charge controller fitted in our Moho with 120w panel and 2 new Varta LFD 90 leisure batteries. Got the Moho out of covered storage ( so nothing for the MPPT unit to do there) and had 2 new batteries installed, put on hook up and put solar fuse back in. By the next day the batteries were boiling! Nice sunny day but the Mppt unit seemed stuck in bulk charge mode ( fast flashing amber light) with fast flashing green light also. Immediately pulled the 15amp fuse on the solar and the boiling stopped. Seems fine on mains hook up so don't think it's an issue with the Electroblock. Both batteries have been tested and are good so it's not a battery problem. Any ideas?