— From our workshop, on YouTube
Honest videos about LiFePO4 from our workshop.
Petr tests, takes apart, assembles and measures — he films in the workshop what others will only tell you over the phone. No sponsors, no marketing. What proves itself, we name. What fails, we show.
New on the channel
A new episode usually every other Friday
Latest videos.
NewHow Petr's on-grid vs off-grid method works. How to connect single-phase microinverters to a three-phase inverter
New‘New’ legislation makes PV more expensive: 6 possible solutions + Petr’s innovative and clever method
NewPV strings - Part 2 (2/2): MLPE (optimisers), Rapid Shutdown, PID, DC losses, 5+1 mistakes
NewPV strings - Part 2 (1/2): string calculation, 3 MPPT limits, protection of parallel strings and DC wiring
01 / Featured series
The solar trilogy.
PV without missteps — three episodes in which Petr walks you through the panels, inverter and battery. Plus a bonus episode for what didn't fit.
02 / Section
15 videos · off-grid systems, ROI, installation
PV systems.
NewHow Petr's on-grid vs off-grid method works. How to connect single-phase microinverters to a three-phase inverter
New‘New’ legislation makes PV more expensive: 6 possible solutions + Petr’s innovative and clever method
NewPV strings - Part 2 (2/2): MLPE (optimisers), Rapid Shutdown, PID, DC losses, 5+1 mistakes
NewPV strings - Part 2 (1/2): string calculation, 3 MPPT limits, protection of parallel strings and DC wiring
PV panel strings - Part 1: wiring, bypass diodes, orientation, safety
What a solar company will never tell you — 5 MYTHS about PV and batteries
Is PV worth it? The rise in electricity prices over the last 10 years has been brutal.
Solar carport — 15.5 kWp, panels as the roof covering for an off-grid PV system
A self-sufficient house in practice — off-grid PV with no grid supply
100 kW off-grid PV + 160 kWh battery — a system optimised for power
Large off-grid PV system — 3 phases, 3 inverters of 11 kW and 96 kWh of LiFePO4
Off-grid PV — just 345 kWh/year short of self-sufficiency. The price of CZK 28 per kWh from the grid is a shock.
An off-grid PV system with 35 kWp and 144 kWh saved CZK 115,000 in a year
Fusing PV batteries and switching inverters by load — safety and efficiency
Recycling in action — ten-year-old bus batteries as the heart of a solar power system
03 / Section
09 videos · Victron, Deye, Voltronic, JK BMS
Inverters and converters.
DEYE hybrid inverter — wiring and setup step by step
The new Victron MultiPlus 6k5 — plenty of power, but what about efficiency under load? A real test
UPS and a small PV system in one — Victron + a quality LiFePO4, an excellent 12 V system
Deye without illusions — BMS communication, monitoring, parallel combination of 12 kW and 20 kW
Deye without illusions — how noisy the Deye is, MPPT and AC coupling with microinverters
Deye without illusions — off-grid PV, 2× 12 kW in parallel + AC coupling
Which is more efficient: DEYE, VICTRON or VOLTRONIC? An inverter test for 48 V systems.
Choosing an inverter for off-grid PV — 1-phase or 3-phase? The load test result will surprise you
JK BMS at full stretch — controlling several inverters via CAN and RS485, Solar Assistant and a 160 kWh battery
04 / Section
23 videos · degradation, safety, long-term operation
LiFePO4 batteries — tests & experience.
Battery SOH doesn't mean what most people think. Capacity? Lifespan? Myths vs facts
Heat KILLS batteries: half the lifespan with a temperature rise of just 10°C (Pb / NMC / LiFePO4)
Does 100% SOC destroy a battery? Voltage and chemistry DECIDE — lead-acid, NMC, LiFePO4
A TRAGIC botch job for 1.4 million: the manufacturer/supplier went bust, WE come to the rescue
Fatal design flaws in an expensive LiFePO4 battery — a complete rebuild is the answer
Pylontech after 5 years in service: 40% degradation? A precise test before and after balancing
Pylontech HV battery — facts about its construction, the most common faults, diagnostics and a real test
The harsh reality of a cheap LiFePO4 from AliExpress — the test ended in flames
How to treat LiFePO4 in winter — a guide, real-world tests and recommendations for periods out of use
Top 7+1 critical mistakes when building a LiFePO4 battery (and how to avoid them)
Top LiFePO4 battery 12 V/320 Ah — heating system and CAN communication for caravans and PV
Pylontech under the microscope — teardown, pros, cons and repair of a faulty unit
Serious fault in a Pylontech LiFePO4 battery — replacing the BMS with a JK with active balancing
The worst LiFePO4 battery I have ever tested — the dismal quality of a cheap Chinese battery
An almost dangerous LiFePO4 battery — shocking insides, expanding foam inside…
Extreme mechanical strength test of lithium cells — will they survive the weight of an excavator?
LiFePO4 voltage vs capacity — where efficiency ends and the risk of degradation begins
Low vs high current — the temperature difference is huge. A real load test of LiFePO4 cells.
Charging frozen LiFePO4 batteries is a road to hell! Test at −15 °C vs 20 °C.
Step by step inside a LiFePO4 cell — an interesting look at the mysterious anatomy of a cell
How important is compression — with poor-quality cells it is actually essential. Who is the real manufacturer?
Testing 80 ELERIX/REPT LiFePO4 cells — will at least some of them get a second life?
Testing 9-year-old Winston LiFePO4 cells — a write-off or in surprisingly good condition?
05 / Section
14 videos · hand-building, JK BMS, compression boxes
Assembly and configuration.
An app developed in the Czech Republic for batteries with JK BMS – monitoring, diagnostics, expert mode, multiple batteries
PV monitoring without Chinese clouds — Solar Assistant on Raspberry Pi
LiFePO4 battery 48 V/320 Ah — 16 kWh for PV, BMS with data communication for Victron
A quality, safe 16 kWh battery for solar — 48 V/320 Ah with data communication
Small but honest! A hand-built 12 V LiFePO4 105 Ah battery from the Czech Republic.
LiFePO4 battery 24 V/315 Ah — construction and detailed setup of a smart JK BMS, Victron communication
Quality LiFePO4 24 V/320 Ah for a small PV system — it can even charge a Tesla. Assembly and load test
A LiFePO4 25.6 V/320 Ah (8 kWh) battery assembly in a compression box
Installing an assembled 24 V/280 Ah LiFePO4 battery in an Aku-box
Assembling a quality LiFePO4 25.6 V/280 Ah battery — 7.1 kWh
How to set up the BMS correctly on a 12 V LiFePO4 battery — JK-BMS and 12 V/105 Ah
How to set up a JK BMS — configuration explained, firmware, Victron communication
TOP balancing LiFePO4 cells — how to do it and how better not to
Cell balancing, BMS calibration and a capacity test of the repaired Ultimatron 25.6 V/100 Ah battery
06 / Section
07 videos · SolarFam, Ultimatron and more
Reviews of specific products.
Pylontech Force H2: teardown and tests revealed the HARSH TRUTH | PART 2/2
Pylontech Force H2: warranty claim rejected and the TESTS brought a SHOCK | 1/2
Solid build or a horror show? SolarFam 12 V/200 Ah LiFePO4 battery
Shock and amazement after opening a branded Ultimatron 24 V/100 Ah LiFePO4 battery
Testing the Ultimatron 24 V/100 Ah LiFePO4 battery — new/newer version of the battery
Detailed test of the Ultimatron 24 V/100 Ah battery — part two
High capacity, unusual height — LiFePO4 12.8 V/320 Ah under-seat battery for motorhomes
07 / Section
03 videos · motorhomes, heating, independence on the road
Caravans and mobile systems.
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