2026 Captain’s Edition
Lithium & DC System Record PDF
Configuration, Commissioning & Cell Balance Log
- 24 Pages / 104 Register Lines A4 and US Letter included.
- 543 Live Fields Interactive and 100% offline.
- 6 Calculation Models E1 through E6.
- Instant Digital Access Download links the moment you pay.
The cell spread is the most useful number in a lithium bank, and no dashboard shows it to you.
Your monitor shows a state of charge and a pack voltage. Both look healthy right up to the day one cell runs away from the others and the BMS starts disconnecting under load. The gap between your highest and lowest cell, read at the top of a charge where imbalance is widest, is what tells you that months in advance.
This record holds that number over time, alongside the configuration it belongs to: what cells, what BMS, what fuse, what each charge source is actually set to, and who signed the installation off.
What you receive
A seven-part record for the life of the bank
- A 24-line reference page for the cell, BMS, charger and inverter figures you transcribe, with the source and page beside each
- A 20-line as-installed record — fuse, disconnect, cable sizes, sensor positions, and what every charge source is actually set to
- Per-cell commissioning readings for up to sixteen cells in series, with the meter recorded
- 16 balance entries tracking cell spread, pack-versus-sum and temperature over time
- A BMS event register including the warnings that cleared themselves
- 6 calculation models for spread, connection loss, deviation, surge sizing, delivered capacity and equivalent cycles
The gap between the drawing and the boat
Part I is what your documentation says. Part II is what is actually fitted — the fuse body you read with a torch, the cable marking, the charger set point measured at the terminals rather than assumed from the menu. Most lithium problems live in the gap between those two pages, and nobody writes either of them down.
Model E2 is the sleeper in this record: pack voltage minus the sum of the cells. A discrepancy there is not a battery problem at all. It is a connection problem, and it is measuring the resistance of a joint that is about to get hot.
Not one published voltage. Deliberately.
Cell voltages, charge currents, balance thresholds and temperature cutoffs differ by chemistry, by cell maker, by BMS and by firmware revision. A charge voltage that is correct for one cell will damage another. A low-temperature lockout that is right for one chemistry permanently plates lithium onto the anodes of the next. So this record publishes none of them — you transcribe yours once, from the documentation that came with your own cells.
Installation is qualified work. This is a record of it.
No page here tells you to fit a fuse, torque a busbar, program a BMS, size a cable or wire a charge source. High-current DC work on a boat is governed by standards, it belongs to a qualified marine electrician, and a lithium bank is the one system aboard that can take the whole boat with it.
Part VI is sixteen lines recording that a competent person verified the installation — and who that person was, with their qualification and the date. Those are questions to put to your electrician, not a checklist for a Saturday afternoon.
Who it is for
- Owners who have just had a lithium bank fitted and want it documented while it is fresh
- Owners who inherited one with no paperwork and need to establish what is actually installed
- Anyone whose insurer or surveyor has asked questions about a lithium installation
- Owners preparing to sell, where an undocumented lithium bank is a discount waiting to happen
Technical specification
| Product ID | AML-ELEC-2026-01 |
| Extent | 24 pages · 7 parts · 6 calculation models |
| Register lines | 104 across reference, as-installed, commissioning, trend and verification |
| Interactivity | 543 live PDF form fields — 60 tick boxes and 483 entry fields |
| Formats included | A4 and US Letter, both fillable and print-ready |
| Systems | Any chemistry, up to 16 cells in series — no chemistry-specific data |
| Units | Unit-neutral — you set them and record which you used |
| Offline | No app, no account, no connection required once downloaded |
What it is not
This document records, structures and compares figures that you supply. It publishes no voltage, no current limit, no temperature cutoff, no fuse rating and no torque figure, and it reaches no conclusion about any installation. It is not a wiring guide, not an integration manual and not engineering advice.
Those decisions belong to a qualified marine electrician working to the standards that apply where your vessel is flagged and used, and to the documentation supplied with your own cells. A lithium installation that is wrong does not fail gracefully.
Instant download. Your links appear on screen the moment payment clears, and arrive by email within a minute. They do not expire.
2026 Captain's Edition · Revision 1.0 · AML-ELEC-2026-01. Apex Marine Labs designs the organisational process behind good seamanship. Our documents record and organise; they do not replace a certified marine survey, an installation standard, or a qualified marine electrician.