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Dear T1 terry

Thanks so much for your detailed answer. I will go with the battery monitor from Victron and program 4 on the pl40. Thanks so much for your help.

I was going to have a bmax of 13.8 and a near useless? float of 13.4V

BRTN of 12.8 V

Hist 0.1V

Is it worth taking them up to 14V once in every few months?

My main concern is that staying so full sitting in my driveway on 13.8 roughly will be keeping them too full for too long. Is this bad for them?

My BMS is programmable so I could set its cut off at 14.1 volts just in case something goes wrong with Pl40 and percentage on the victron. It might set off near the 100 percent level on the victron. I have yet to work a few things out as I now have three devices in the equation. I have balanced them to 14 volts in parallel for a few months and they are now sitting at 13. 35 volts ready to be rebuilt in series. My biggest loads and charges will be well under 0.25 C (200 amp hour) for now as I only have a small inverter (300 watt victron). I am hoping for longevity from these. Thanks again for your help.

When not actually working each day and left idle for more than a few mths, discharge till each cell is below 3.3v and disconnect the battery negative, all of them, even the ones that feed any cell loggers. If they are going to power something during the night but only a minimal % drop in SOC, set the boost voltage to 13.9v, absorption to 13.8v for 20 mins and the float to 13.7v. Every 30 days set the equalise to 14.1v for 0.1hrs to 0.2hrs, (6 to 12 mins) and this will return the battery to 100% and auto reset the Victron BMV to the correct SOC.
You are monitoring each parallel cell group voltage I hope? The charging must stop if a cell goes over 3.6v to avoid cell damage, a very short trip to 3.8v can be tolerated but it will cause a very rapid out of balance if charging isn't set to stop at cell voltages rather than battery voltage, this always leads to the death of at least one cell group in any battery, no matter what chemistry is used

T1 Terry

Hi Dale, just a quick one to Terry much the same as yours .
Terry do you recommend I do the same as you have said to Dale , just disconnect my earth lead as I have nothing running while we are home ?
Bernie .

BernieQ2 wrote: ↑Fri Jul 10, 2020 2:41 pm Hi Dale, just a quick one to Terry much the same as yours .
Terry do you recommend I do the same as you have said to Dale , just disconnect my earth lead as I have nothing running while we are home ?
Bernie .

If it is a lithium battery, don't leave it on a charger, they don't like it at all. Disconnect the battery negative and leave it disconnected until you are ready to use it again. If it will only be a few weeks or so, don't worry about it, but a few mths, better to disconnect the battery so no phantom loads drain it flat while you aren't watching it

T1 Terry

Thanks Terry... don't have a charger it's only on solar..
Do I still disconnect ,?
Bernie .

BernieQ2 wrote: ↑Fri Jul 10, 2020 3:44 pm Thanks Terry... don't have a charger it's only on solar..
Do I still disconnect ,?
Bernie .

Are you running anything over night to use a bit out of the battery? If the van in in a good sun spot, even if you just leave an LED light on to use a bit over night so the solar has something to replace in the battery, then just leave it all connected up and running.
Lithium batteries do not have a cycle life as such compared to lead acid batteries. A cycle in a lithium battery is fully discharged to 0% SOC, then recharged to 100% SOC, anywhere between 20% and 95% has no effect on the battery life, no matter how often it moves within this range.

T1 Terry

No Terry there is nothing running...its only for the fridge which is not on...
Yes it's in full sun majority of the day .
It's been on float since we arrived home a week or so back .
Bernie

Thanks terry I appreciate what you have told me so much. Great information. Yes I am monitoring individual cells (4 cells). Many thanks. Its been a wonderful return to the forum. Keep in touch Bernie. Bernie -doesn't that stuff up the controller disconnecting the battery? Shouldn't you disconnect solar first then the battery from the scc?

G,Day Dale..Yep I was thinking that as the set up requires the battery connected first before the solar.
I might turn the fridge on to lower the volts in the battery then do a reverse disconnect .
Think I will call the Vicron people and get their advice/instructions ? .
Yep good to see your still about Dale keep your posts coming .
Bernie .

Yes we run our fridge 24/7 on solar power keeps the battery [emoji367] going [emoji848]


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