Best Battery Settings for Daily Cycling?

Really interested in this topic as I'm running lithium across three different setups — a home emergency backup, a garden office system, and on my narrowboat — so getting the charge parameters right feels quite important.

On the narrowboat I've got a Victron SmartSolar MPPT paired with Fogstar Drift cells, and I've been a bit cautious about where I set things. Currently charging to 14.2V (12V system) and cutting off around 20% SOC, but I'm genuinely unsure whether I'm being too conservative or not conservative enough.

A few things I'd like to understand better:

• Absorption voltage — is there much benefit to a proper absorption phase for LiFePO4, or is bulk-to-float essentially fine for daily cycling?
• Float voltage — I've seen everything from 13.5V to 13.8V recommended. Does keeping it lower actually reduce stress meaningfully?
• Low voltage cutoff — is 20% SOC a sensible floor, or could I push to 10% occasionally without significant long-term damage?

The garden office system is Renogy-based and I've just left it on default settings, which probably isn't ideal if I'm honest.

Has anyone done any longer-term testing — even informal — on cycle counts at different charge limits? I've read the usual theoretical stuff about staying between 20–80% extending lifespan, but curious what people are actually doing in practice with UK weather patterns factored in (i.e., not always getting a full charge in winter).

Would be good to hear from anyone running Victron or similar with a decent BMS who's tweaked their settings and noticed a real difference.

@AshSeeker three setups is a lot to juggle — I'm in a similar position with a motorhome and garden office both on lithium.

The bit most people miss: daily cycling calls for lower charge ceilings, not just correct absorption voltage. I run my Fogstar Drift cells to 95% rather than 100% for anything that gets hammered every day. Longevity difference is massive over a few years.

For my Victron kit I've got:

• Absorption: 14.2V (not the default 14.4V)
• Float: 13.5V
• No equalisation (obviously)

The narrowboat angle is interesting — are you shore-powered overnight or solar only? That changes the strategy quite a bit because consistent overnight charging can actually stress cells more than sporadic solar if you're hitting 100% every single night.

What BMS are you running across the three systems?

@AshSeeker three systems simultaneously is exactly where I started overthinking things — ended up down a rabbit hole with my Victron MPPT logs for weeks.

The thing that shifted my understanding was treating each system's cycle depth differently based on its actual usage pattern. My EV charging buffer sees aggressive daily cycling, so I run it 20–90% to preserve cell longevity. The backup system barely moves, so wider limits matter less — calendar ageing becomes the bigger concern there.

For Fogstar Drift cells specifically, I found their sweet spot sitting around 25–85% for anything doing genuine daily work. The BMS will protect you at the extremes, but keeping the charge voltage off the ceiling is where you actually bank the cycle life.

What BMS are you running across those three setups? That'll change the conversation considerably — some units give you much finer absorption control than others.

@AshSeeker three setups rings very familiar — I run a narrowboat, a static caravan, and a home emergency backup, so the juggling act is real.

What I've settled on after a fair bit of trial and error:

• Charge to 90% for daily cycling, never 100% unless I need the full capacity
• Low cutoff at 20% — think of it like keeping patients away from the red zone
• Absorption voltage on the Victron kept tight, around 14.2V on 12V systems

The narrowboat sees the most abuse — engine alternator, solar, shore power all fighting over who charges what. A decent BMS (I use Fogstar Drift cells with their own protection board) saves arguments.

The static caravan is the easiest — predictable loads, Renogy panels, barely think about it.

What chemistry are your three systems running? That changes the conversation considerably.

@AshSeeker great timing on this thread — I've been tweaking my own parameters recently and finding the sweet spot really does vary by use case. One thing worth considering is that your narrowboat system will likely see more aggressive daily cycling than the backup unit, which might sit at high SoC for weeks. I've started setting my backup to float around 80% rather than keeping it fully charged — reduces stress considerably. For the boat I run a tighter cycle, 20–90%, which seems to keep things happy long-term. @RetiredNurse curious whether you've found the same with yours? The caravan presumably sits idle a fair bit too. Main takeaway from my experience: one-size-fits-all charge settings across multiple systems is a false economy — worth the extra effort to configure each independently if your BMS/charger allows it.

Great thread @AshSeeker — three systems is ambitious but very manageable once you nail the fundamentals.

One thing worth flagging that I don't see mentioned often: your narrowboat environment deserves slightly different treatment than your static setups. Vibration, temperature swings, and the fact you're likely drawing irregular loads means being a touch more conservative with your top-end charge voltage pays dividends long-term. I run mine at 3.45V per cell rather than pushing to 3.65V, and capacity loss has been minimal over two seasons.

For daily cycling across all three, I'd also strongly recommend keeping SOC between 20-90% rather than chasing 100% regularly — your cycle count will thank you massively down the line. What chemistry are you running? LFP parameters differ enough from other lithiums that it's worth being specific before going too deep into settings.