I've lived off grid for 22 years, in a treehouse in a remote part of Hawaii Island. Parts fail out here, and I see troubleshooting a failing part as part of life. A Honda EU2200i backup generator is a requirement for me, not an extra.
My system is four REC Alpha 72 XV 445 W panels (1,780 W), a PowMr HHJ-60A charge controller at 12 V, four EVE MB31 314 Ah LiFePO4 cells in series (12.8 V, 4.02 kWh) with a 150 A JK BMS, a Blue Sea Class T 300 A fuse and a BELTTT 3,000 W 12 V pure sine inverter. It runs two laptops, a monitor, Starlink and TP-Link networking.
I haven't written down my own habits here, because I'd rather not dress them up. What follows is the checklist I'd want in front of me: each line is taken from the manual for that kind of part, and the source is listed at the bottom. If you keep a record and find a line that doesn't match your own gear, trust your manual over this page.
If you see a mistake anywhere on this page, I'd like to hear about it.
None of my manuals gives a weekly interval, so this is a suggested quick look, mostly reading screens rather than touching anything.
| Part | What to check | Interval | Source | |
|---|---|---|---|---|
| Battery (JK BMS) | Open your BMS app (mine is a JK). Write down the highest and lowest cell voltage and the gap between them. JK starts balancing when the gap is above its trigger setting (0.01 V by default). A gap that keeps growing week after week is a question for your BMS maker. | Suggested | [4] | |
| Battery cells | Is any cell below 2.8 V in normal use? EVE says to charge regularly to keep cells above 2.8 V, and that over-discharge is forbidden. | Suggested | [3] | |
| Battery area | Look, feel and smell. EVE says if a cell gives off a strange smell, heat, discoloration or deformation, stop using it right away. Don't open or repair cells yourself; EVE says cell maintenance is for trained professionals. | Suggested | [3] | |
| Charge controller | Read the display. Working mode 3.0 is night, 4.0 is MPPT, 7.0 is absorption and 8.0 is float. Codes to look up: 18 (PV voltage low), 60 (over-temperature), 63 (battery voltage high), 65 (battery voltage low), 71 (PV voltage high), 73 (over-charging current). | Suggested | [2] | |
| Inverter | Fans not blocked, vents clear, no moisture near it. | Suggested | [7] | |
| Panels | From the ground: new shade on the cells, visible dirt, anything cracked or loose. REC says panels should not be shaded at any time of year. | Suggested | [1] |
Why write the cell gap down? A single reading means little. A gap that grows over months is the kind of slow change I'd want to catch early. The 1.8 kW solar guide covers how this bank and controller fit together.
| Part | What to check | Interval | Source | |
|---|---|---|---|---|
| Panels | Clean only if dirt is clearly visible. REC: clean when the panels are cool (early morning) to avoid thermal shock, and never stand, lean or rest a bucket on the glass. REC says to use deionized water free from grit, with a sponge, microfiber cloth or soft brush, and that acidic or alkaline detergent may not be used. If in doubt, stop and get professional advice. | When dirty (REC) | [1] | |
| Charge controller | Clear debris away from it and keep about 5.9 in (15 cm) of space around it. No water may get in; it's an IP21 enclosure, meant for a dry indoor spot. | Suggested | [2] | |
| Inverter | Dust in the vents and fans. Renogy asks for at least 10 in of clearance, a dry spot and no direct sun on the fans. Victron says to keep the unit clean and away from moisture, oil, soot and vapors. | Suggested | [7][6] | |
| Class T fuse and battery cables | Is the insulating cover on the fuse block? Blue Sea fits it to meet ABYC/USCG insulation rules. Are the cables supported, not rubbing or hanging loose? | Suggested | [5][1] | |
| Generator, if idle | If it has sat for 1 to 2 months, Honda says to fill with fresh gasoline and add stabilizer. See the generator schedule below. | Honda storage table | [8] |
This is the one where I'd shut things down and put hands and tools on the system. If you aren't comfortable working near a battery bank that can deliver hundreds of amps, this is the visit to book an electrician for.
| Part | What to check | Interval | Source | |
|---|---|---|---|---|
| All DC connections | With everything safely shut down: every connection secure, tight, clean and free of corrosion. Victron says checking all connections once a year is enough for its inverters. REC asks for regular checks of connections, fasteners, cables and ground bonding. Tighten to the maker's number and no further. Renogy warns that over-tightening its terminals can damage the inverter, and PowMr warns that too much torque on its casing screws can damage the circuit board. | Once a year (Victron) | [6][1][2][7] | |
| Torque values I could find | Blue Sea Class T block (225 to 400 A): 107 in-lb (12.1 N·m) maximum on the stud nuts. EVE MB31 cell poles: 6 N·m maximum. REC panel clamps: 12 to 25 N·m, or what the clamp maker says. If a number on your own part disagrees, ask the maker before going higher. | When tightening | [5][3][1] | |
| Panel mounting and connectors | Fasteners and ground bonding points tight and free of corrosion. Connectors mated like-for-like only (same maker and type), cables secured on both sides of each connector, and no extra grease or heat shrink over the connector so it can dry out. | Regularly (REC) | [1] | |
| BMS settings | If your BMS is a JK like mine, compare its settings to EVE's limits. JK's LiFePO4 defaults are 3.6 V cell overcharge, 2.6 V undervoltage and 2.5 V shutdown. EVE allows charging only from 0 to 60 °C, while JK's default low-temperature charge cutoff is −20 °C. If your bank ever gets near freezing, ask JK or your installer about that setting. JK's app also has a voltage calibration setting; comparing it to a good multimeter once a year tells you if it has drifted. | Suggested | [4][3] | |
| Charge controller settings | Still on lithium (setting D04 = 01), and is the highest charging voltage (D02) still what your battery or BMS maker says? PowMr says its defaults work for everything except lithium, so a reset matters. PowMr also says to change settings only with the panels disconnected. | Suggested | [2] | |
| Battery health | Is runtime shorter than last year with the same loads? Look at the cell-gap notes in your log. | Suggested | [3] |
On the fuse: the torque figure above is from Blue Sea's drawing for its 225 to 400 A Class T block. If your fuse holder is a different one, use the number printed in its own instructions. On the BMS: the JK figures here are from JK's B2A24S-30P manual, a related model, so settings names and defaults can differ on yours; check your own manual.[4] If runtime seems shorter than it used to be, the battery runtime guide walks through checking it against the published specs, and the 1.8 kW solar guide explains why I plan on using about 80% of the bank. If a fuse ever blows, the question is why, and that's a question for an electrician before a new fuse goes in.
Here the manual does give a schedule, so I'd follow it as written.[8] Before each use, Honda says to look around and under the engine for oil or gasoline leaks, check the oil level, check the air filter and check the fuel. Honda also notes the Oil Alert system will shut the engine down if the oil is low.
| Item | Job | When | |
|---|---|---|---|
| Engine oil | Check level | Each use | |
| Engine oil | Change | First month or 20 h, then every 6 months or 100 h | |
| Air cleaner | Check | Each use | |
| Air cleaner | Clean | Every 3 months or 50 h (more often if dusty) | |
| Spark plug | Check and adjust | Every 6 months or 100 h | |
| Spark plug | Replace | Every year or 200 h | |
| Spark arrester | Clean | Every 6 months or 100 h | |
| Valve clearance | Check and adjust | Every year or 200 h (dealer) | |
| Combustion chamber | Clean | Every 300 h (dealer) | |
| Fuel tank and filter | Clean | Every 6 months or 100 h (dealer) | |
| Fuel tube | Check, replace if needed | Every 2 years (dealer) |
Items marked "dealer" are ones Honda says your servicing dealer should do unless you have the tools and are mechanically proficient. Honda says skipping the schedule can lead to failures the warranty won't cover. For sizing questions, the backup generator guide covers how this generator charges the same bank.
This matters more for a seasonal cabin than for a place someone lives in full time.
The checklist only helps if I can compare this month to last month. A plain log is enough. These columns are the readings the manuals above point to.
| Date | Pack V | Highest cell V | Lowest cell V | Gap (mV) | BMS alarms | Controller mode / code | What I did |
|---|---|---|---|---|---|---|---|
Cite this page: MiniGridMap, "Off grid solar maintenance checklist and battery maintenance log", https://minigridmap.com/guides/off-grid-solar-maintenance-checklist/ (2026). The checklists and log may be printed and reused with a link back.
For the same system: How far does a 1.8 kW off-grid solar system go?, How long will my 12 V LiFePO4 battery last? and How big a backup generator does a 12 V LiFePO4 off-grid system need? All guides are on the guides page.
Planning a system for a cabin? See Off grid solar system for a small cabin, sizing step by step for a weekend cabin and a full-time cabin.
The system described is the site owner's own. Every checklist item is taken from the cited manufacturer documents; intervals without a manufacturer source are labeled as suggestions.