Limit Lithium battery charging to 80% with Victron SmartSolar

[Richpatty]

I know I should know this….but if I am parked with shore power, the solar will keep the lithium’s at 90-100% at all times. Is there a way to limit it to 80% SOC? Can you set it to a certain voltage level (i.e. 13.2v or so) to achieve this? I have a Victron SmartShunt, but I am not sure it will talk to the SmartSolar (at least for SOC).

For now, I am managing this manually, by shutting off the solar charging until the batteries get low enough to charge….but then I have to catch it before it gets to 80%. I have the magnum charging off.

Thoughts?
Rich

 

[Richpatty]

@Chuggs , @Neal

Thoughts?

 

[Neal]

Well, I was hoping to stay out of this haha. My opinion, as stated in another thread on this topic, is this doesn't apply to LiFePO4 chemistry. I think it's more important for LiFePO4 batteries to keep cells balanced and that requires some discharging at times to 100% charge from what I understand. I don't think we are going to see any effects in our usage or ownership time that will benefit from the 80% charge "belief" and in fact I've been reading the benefit to iPhones has proven to be minimal such that I have mine set to charge to 100% every night and do not use Apple's battery saver whatever it's called.

Just my $.02 - it's not worth dealing with and may be incorrect for this battery chemistry. But I'm all ears and open to learning from others.

 

[MemoriesByTheMile]

I too am waiting for others who may know more.
I had adjusted my charging settings based on trial and error to have charging stop in the 80-85% range.
But then I learned that my battery cells were not properly being equalized by doing this.
So I have reverted back to my original settings so that we hit 100% regularly.
Our batteries (Lithionics brand) are nearing 10 years old and still doing well. Have no plans to replace them anytime soon.

 

[Richpatty]

Thanks guys. I agree that going to 100% is something that should be done on a regular basis…but was not sure if sitting at 100% most of the time is good either…. I think if you are using your solar on a regular basis (boondocking or on a home), then just letting is go is fine. But we don’t use our RV to boondock as often as I had imagined or hoped, so anytime we are out, they sit at 100% much of the day (due to solar) and don’t drop too much below 95% overnight.

When my RV is home,it is covered and unplugged (except a trickle charger on the chassis batteries) so I usually just cut as much load off the house batteries and let them sit. I can usually get at least 30 days before they need any charging, at which time it is time to take the RV for a drive anyway (and run the generator). So maybe I am over thinking this (wouldn’t be the first time) and having the lithium’s “rest” between trips is good enough.

Thanks for the sounding board.
Rich

 

[Neal]

I’ve been plugged in at CG’s and far too many months in storage and I’m happy keeping it at 100% personally.