Own initiative · public project
Zelf je batterij
A free knowledge base and set of calculators that help Dutch boat, camper, and off-grid users better calculate, understand, and monitor a LiFePO4 system — sober, evidence-based, and without marketing speak. Our own initiative, live at zelfjebatterij.nl.
- Status
- Live knowledge base and calculators · monitoring concept under research · Status reviewed · July 2026
- Ownership
- Designed and built by PolderLabs
- Permission
- Own initiative · public
The situation
Boat, camper, and off-grid users in the Netherlands deserve sober, evidence-based guidance about LiFePO4 instead of marketing copy. We set out to ship a free knowledge base plus calculators that are honest about assumptions and limits — and that make explicit what they are not.
What we built
A plain-Dutch knowledge base on capacity, BMS, charging, monitoring, and safety. Calculators with assumptions and margins shown in the result. A monitoring concept that explicitly does not pretend to be a BMS or safety-critical control.
Knowledge base
Seven articles on capacity, BMS, charging from shore, alternator, or solar, monitoring, moisture, and safety — written in plain, sober Dutch.
#kennisbankCalculators
A capacity and charge-time calculator plus the Electric Sloep Explorer, with assumptions, margins, and warnings shown in the result.
#rekentoolsResearch
A monitoring concept with a waitlist and long intake form, explicitly not intended as a BMS, fire-protection, or safety-critical control.
#onderzoekSafety boundaries
An independent safety page makes clear what the tools are and are not — no sales copy, no false certainty.
#veiligheidsgrenzenSee the sloep explorer live
A short walkthrough of the free tool: hull speed from waterline length, three scenarios side by side, shore-power calculation, and how to save your boat profile for later.
Our role
PolderLabs designed the content strategy, wrote the articles, built the calculator architecture with Zod-validated inputs, and made the UX and safety boundaries explicit. It runs separately from paid engagements.
Evidence
The site is live at zelfjebatterij.nl. The capacity and charge-time calculator and the Electric Sloep Explorer are verified via the live implementation and site.config.ts. We publish no unsupported counts, users, or growth numbers.
What this proves
Shipping a complete niche product — content strategy, calculators, UX, safety boundaries — with the same no-nonsense attitude as our engineering practice, and keeping it cleanly separated from paid work.
Limitations
NL only. The Sloep Explorer and monitoring concept are explicitly Beta/research, not production rollouts. Not a substitute for an installation review, a BMS, or safety-critical control.