My Smartsolar 100/50 has been working fine for nearly 2 years but recently has been regularly showing a battery overvoltage fault and indicating 26.5V even though it is, and always has been, set for 12V system. Connected to 2 x 400W panels and 4 x 100Ah lifepo4 batteries. Doesn’t do it every day but has happened about 3 out 4 days in recent weeks. Have disconnected and done a hard reset but still faulting. As soon as I turn on a heavier load like the 12V hot water system, it reverts back to 13.8V. When I turn load off, it creeps back up to 26+ volts. Anyone encountered this issue?
What firmware is it running?
V1.64 says it’s the latest version. 4 LiFePo4 in parallel. I would have thought a battery shut-down would have to be all 4. Generally occurring later in the day when batteries are on float.
I’ll try disconnecting 1 battery at a time and see what effect that has. Didn’t exactly buy the most expensive batteries in the world, kinda the opposite…
I do have an Orion 2412/30 DC charger also but is currently disconnected via the 24V start battery system isolator switch so it doesn’t even show in the app. Doubt that’s the issue. The lithiums have never been under 13.15V in almost 2 years but will try taking one off-line at a time to test voltages etc and see if the problem still exist.
When a battery shuts down and a system is sending power to it, it can cause quite a spike.
So to be expected.
You would probably need to check the battery health a bit.
Maybe lower the charge amps or voltage down by 0.2v to see if it calms down.
My first idea was a terribly mislead assumption so ignore it.
I will try eliminating batteries tomorrow, probably well overdue for a balance charge anyway. Not really what I’d call a spike, the voltage stays constant at 26.45V until I load it up or the fridge kicks in. Input charge current shows 0 watts. After I turn something on and clear the fault it resumes charging as normal except sometimes it keeps behaving, other times it runs away again and wants to be a 24V system…
And the fault is consistently 26.45v and doesn’t fluctuate. Only drops back to normal under load. Got me stumped but I’m relatively new to lithiums. Been fantastic up to this point. Have got an easysolar 12/1600 ordered but intend to use the 100/50 as well on my trailer bank to replace 100/30. Maybe if I connect the 100/30 it will eliminate the 100/50 but the system can go days without faulting then do it 4 days in a row! What is the chances of a 12V lithium identifying as a 24V battery? Wouldn’t think that’s possible.
Connect an agm with jumper cables in parallel to your lithiums
I don’t actually have an AGM to try this… To clarify, it doesn’t try to charge at 24V. What would this actually achieve? Just need to determine if it’s a controller fault or bizarre battery behaviour. Only does it when very little load, just things on standby.
Connect your starter battery instead
Again, what exactly is that going to achieve? It’s not like I can leave one of my 24V starter batteries connected to my 12V house bank.
Not likely
If it is intermittent then it could be related to speed of charge vs balancing. An older lithium battery struggles more and more as they age.
Sorry, didn’t know you have 24v there
I didn’t think that 50A of charge would be considered too fast for 400Ah. Often it doesn’t reach 50A at all. The batteries are not quite 2 years old and for 7 months of that we were overseas with system powering nothing and maintained at 13.8V. So they have done well under 700 cycles, Assuming they should be good for 2k to 5k cycles, and rarely discharged by more than about 20%, they should really be in decent condition. I also assume that the batteries would shut down at 26V which would explain why the voltage returns to normal when loaded up. I’m fairly convinced it’s the controller rather than the batteries but I’ll test them first of course. Will also leave a load on all day like a fan or high wattage LED, I’ll bet it won’t fault, just not exactly sure why!
have you manually configured the battery settings in the MPPT to fix the battery voltage, and to limit the Abs and EQ voltages to 14.4? rether than leaving the battery on autodetect?
Yes, as you literally require a code from victron to change from 12 to 24v. Unit has been working perfectly for nearly 2 years, only started faulting in recent weeks.
Absorption set at 14.5V, float 13.85. Fault only occurs on float.
Do try to reduce your Abs Voltage to 14.3, This can be done with the Victron connect app and no code.
Actually tried it at 14V absorption, still faulted.