Solar Camping FAQ - Self-sufficient power supply
Welcome to electronicx, your specialist for mobile energy since 2006. From the right battery to the perfect solar system – here you will find well-founded answers with concrete figures so that your camping trip is a success off-grid.
Basics
What does a solar system really do for me when camping?
A solar system makes you independent of mains power and significantly extends the service life of your on-board battery. With a 120 watt solar module you generate around 400-600 Wh on an average summer day in Germany, enough to charge a 100Ah lithium battery to 80%. You can run a cool box (40 watt), LED light (10 watt) and smartphone charging (15 watt) for over 24 hours with this. With good alignment this is enough for unlimited standing times without running the engine – the generator replacement par excellence.
Which battery is the best for solar camping?
For solar camping we clearly recommend a LiFePO4 battery, specifically our electronicx 100Ah with 12.8V nominal voltage. It weighs only 12.8 kg, delivers 1280 Wh of usable energy and handles 3500 full cycles at 80% depth of discharge. Compared with lead-acid (only 500 cycles at 50% DoD) it lasts 7 times longer. The integrated BMS electronics protect against deep discharge, overcharging and cell drift. The 100Ah lithium currently costs 499 Euro from us – calculated over its service life that is about 14 cents per cycle.
How long does a 100Ah battery last with a cool box and light?
A typical compressor cool box draws an average of 3-4 amps at 12V, LED lighting about 0.8 amps. Together that is roughly 4.5 amps of continuous load. From a full 100Ah lithium battery (100Ah usable, as 100% DoD) you can theoretically cool and light continuously for 22 hours. In practice, with solar recharging on a sunny day – a 120Wp module delivers 6-8 amps – you extend the runtime indefinitely. The battery guard only switches off at 10.8V, which is reached after about 90Ah drawn.
What do MPPT and PWM mean on a solar charge controller?
MPPT controllers (Maximum Power Point Tracking) are around 30% more efficient than cheap PWM controllers. Our electronicx MPPT 75/15 for 149 euros converts the high module voltage (e.g. 18V) into 14.4V charging current with low losses and still harvests energy even in diffuse light. PWM controllers, by contrast, simply switch off once the battery voltage is reached and waste the surplus voltage. With a 120Wp module, MPPT delivers a real 7.1 amps of charging current, PWM only 5.5 amps. For camping with changing conditions, the extra cost is recouped after 2-3 trips.
Cold cranking amps CCA – do I need them for camping?
The CCA value (Cold Cranking Amps) is of secondary importance for pure camping batteries, as you rarely have to start an engine. Our electronic 100Ah lithium does deliver 200A briefly, but what matters is the continuous discharge capability of 100A. For starter batteries in a motorhome, however, look for at least 800 CCA – our EFB 95Ah manages 850 CCA for cold mornings and reliable engine starting. Camping batteries are optimised for cycle stability, not for short high-current bursts.
How many solar watts do I need in a motorhome?
For a standard motorhome with a 100Ah battery, 120 watts of solar module is enough for continuous operation in summer. In spring/autumn it should be 180-200 watts. For larger batteries (200Ah) we recommend 300 watts peak. Figures: a 120Wp module delivers an average of 480 Wh per day in Germany (July), only 180 Wh in October. With 200Wp it is 800 Wh in summer, sufficient for a cool box, water pump, light and laptop. We offer the 120Wp set incl. MPPT controller and cables for 379 euros.
What is the difference between AGM and lithium for solar?
AGM batteries (Absorbent Glass Mat) cost around 179 euros for 100Ah, less than lithium (499 euros), but you can only use 50% of the capacity – effectively 50Ah. Lithium delivers 100% usable 100Ah and 3500 cycles instead of 500 for AGM. Over 10 years of camping (500 cycles per year) you pay about 1074 euros for AGM incl. replacement, for lithium a one-off 499 euros. Lithium weighs 12.8 kg instead of 30 kg and charges twice as fast at 50A. Crucially: lithium tolerates partial cycles without capacity loss, AGM must be fully charged regularly.
Can I use my car battery as a solar battery?
A starter battery is designed for short high-current bursts (CCA 680-850), not for the slow, deep discharge of solar operation. Even 5-10 complete discharge cycles below 50% capacity damage a starter battery irreparably. The plates are thinner and corrode faster. Always use a separate leisure battery – our 80Ah AGM for 139 euros or 100Ah lithium for 499 euros are ideal. A split charge relay for 49 euros prevents the starter battery from being discharged and charges both batteries while driving.
Do I need an inverter for 230V when camping?
For most devices, no – many camping gadgets run directly on 12V or USB-C (PD up to 100 watts). An inverter turns 12V direct current into 230V alternating current, but with 10-15% loss. A 300 watt model for 89 euros is enough for laptop power supplies (65 watts for 8 hours a day = 520 Wh, so almost half the battery). For a hairdryer (1500 watts) or coffee machine you need at least 2000 watts continuous power – that costs 349 euros and puts a heavy load on the battery: 1500 watts for 10 minutes means 25Ah drawn, which with a 100Ah lithium is 25% of the capacity.
How do I charge my camping battery while driving with solar?
Ideally you combine solar and alternator with a battery-to-battery charger (B2B), e.g. our Votronic 30A for 179 euros. It combines the solar input (max. 360Wp) and the alternator current and charges the leisure battery with up to 30 amps. While driving, solar 20V and alternator 14V come together and deliver up to 45A of charging current – a 100Ah lithium battery is full in a good 2 hours. Without B2B you must separate the solar modules and the alternator so as not to damage the electronics.
Technology & specifications
Which charge controller for 200 watts of solar on the motorhome roof?
For 200Wp you need an MPPT controller with at least 20 amperes rated current. Our Victron MPPT 100/20 for 119 euros handles up to 100V input voltage (two 18V modules in series = 36V safely). With optimum alignment it delivers 14.3 amperes to the battery. Alternatively the electronicx MPPT 75/15 for 99 euros, which with the modules connected in parallel (18V, 5.5A per module) provides 11 amperes. Important: cable cross-section of 6mm² between controller and battery (max. 2 metres length), otherwise voltage drop of 0.3V and charging power loss.
How many ampere-hours per day does a 150 watt panel produce?
With optimum south-facing alignment and 45 degree tilt, a 150Wp module in Germany delivers: July on average 600-750 Wh, which corresponds to 50-62 Ah at 12V. December only 60-90 Wh (5-7.5 Ah). On average over 20 camping days in summer with 5 sun hours per day, this gives 750 Wh or 62.5 Ah daily yield. With real losses (shading, temperature, controller) calculate with 45-55 Ah net. That is enough for the daily consumption of a cool box (35 Ah), LED (5 Ah) and smartphone (3 Ah) and still leaves reserve for the battery.
What do the cycle figures for lithium batteries mean?
A cycle is a complete charge and discharge. For our 100Ah lithium battery, the specifications provide for 3500 cycles at 80% depth of discharge (80Ah per cycle). After 3500 cycles the battery still has 80% of its original capacity – i.e. 80Ah usable. With daily use in camping (150 days a year) you reach this number of cycles after more than 23 years. Partial cycles (e.g. 30% discharge) count proportionally: 3 partial cycles of 30% correspond to one full cycle. The BMS electronics track the cycles and actively balance the cells – the service life depends on use, charging, temperature and care.
Can I charge my 200Ah solar battery with 230V mains power?
Yes, with a suitable charger. For lithium iron phosphate (LiFePO4) we recommend a specific profile: constant current 14.4V, then float at 13.6V. Our electronicx charger 25A for 249 euros charges a 200Ah lithium battery from 0 to 100% in about 8 hours (25A x 8h = 200Ah). It is faster with the 50A model for 379 euros – full in 4 hours. Important: do not use a lead charger with a descalation or desulphation mode, as that destroys the lithium cells. The integrated BMS does protect, but wrong profiles drastically shorten the service life.
What cable cross-section do I need between solar module and controller?
With 6 metres of cable length between a 120Wp module and an MPPT controller, a 4mm² cable cross-section is sufficient for 2% voltage loss (0.36V). With 200Wp and the same length you need 6mm². The voltage drop is calculated: A = (cable length in m x current in A) / (56 x permitted voltage drop in V). Example: 12m cable length (there and back), 7A current, 0.36V loss = 12 x 7 / (56 x 0.36) = 4.17mm², so choose 6mm². Our solar cable set for 31.90 euros contains 6 metres of 4mm² with MC4 connectors, suitable for most roof installations.
How does the BMS prevent deep discharge of my camping battery?
The Battery Management System (BMS) monitors each individual one of the 4 cells in the 12.8V lithium battery. If a cell drops below 2.5V (total voltage approx. 10.0V), the BMS switches the output off completely. The battery then appears dead, but is internally protected against deep discharge. A brief charging current of 12V reactivates the BMS automatically. Our electronicx 100Ah also has integrated temperature sensors: below -5°C the BMS blocks charging (lithium cells would otherwise be damaged), but discharging is possible down to -20°C. The balancer function equalises the cell voltages to within 50mV.
What is the difference between rated capacity and usable capacity?
The rated capacity (e.g. 100Ah at C20 rate) indicates how much current the battery delivers over a 20-hour discharge – i.e. 5 amperes over 20 hours. At higher current draw the available capacity falls: at 20A load the same battery only manages 90Ah (Peukert effect). Usable capacity depends on the battery technology: AGM allows 50% depth of discharge (50Ah usable), lithium 100% (100Ah). Our 100Ah lithium still delivers 95Ah at 100A load – the voltage only drops minimally from 13.2V to 12.8V. This flat discharge behaviour is a main advantage for camping with varying loads.
How do I connect several batteries in parallel for more capacity?
Two 100Ah lithium batteries connected in parallel give 200Ah at 12.8V. Use identical batteries (same voltage, same age) and connect positive to positive (red) and negative to negative (black). The cross-section of the parallel cables must be at least 25mm² to limit the voltage drop to 0.12V at a 100A load. Our parallel connector set for 49 euros contains two 30cm cables 35mm² with M8 cable lugs. Charge the batteries individually fully before connecting in parallel – otherwise equalising currents of over 50A will flow. The BMS of each battery remains active and protects independently.
What protection class does the electrics need in the camping area?
All components in the outdoor area should be at least IP65 – protected against water jets. Our solar modules meet IP67 (short-term immersion), the junction boxes IP68. The charge controller must be installed dry (IP20 internal), as its cooling fins cannot tolerate moisture. Batteries are protected to IP54 (splash water), but not gas-tight – lithium has no gas emission, lead-acid does and requires ventilation. The 12V distribution with fuses (30A per outlet) costs 59 euros and is IP44 – protected against splashes, but not suitable for washrooms. Cable glands with strain relief are mandatory.
How do I recognise a high-quality solar cell for camping?
High-quality monocrystalline cells have an efficiency of 21-23% and a positive power tolerance (+3%). Our 120Wp modules from Aleo Solar reliably deliver at least 123 watts. Look for PERC technology (Passivated Emitter and Rear Cell) – it reflects light at the rear and increases yield by 5-8% in diffuse light. The bypass diodes (3 per module) prevent power loss in partial shading. High-quality modules have tempered ESG solar glass with 4mm thickness and anodised aluminium frames. Cheap modules with flexible plastic cells degrade by 3-5% per year, our rigid modules only 0.5%.
Purchase & delivery
Which lithium battery for camping at electronicx in 100Ah?
Our best-selling electronicx LiFePO4 100Ah with 12.8V costs 499 euros including Bluetooth monitoring. It delivers 100 amperes continuous current (200A peak for 5 seconds), has 3500 cycles at 80% DoD and weighs only 12.8 kg. The integrated smart BMS shows charge level, cell voltages and cycle count via app on your phone. Alternatively the 150Ah variant for 699 euros (1920 Wh) or the narrow 80Ah for 399 euros with only 9.6 kg. Orders placed by 2 pm leave our warehouse in Cleebronn on the same working day.
What does a complete solar system for a motorhome cost?
A complete set of 120Wp solar module, MPPT controller, 100Ah lithium battery and mounting kit costs 1047 euros at electronicx. Broken down: 120Wp module 229 euros, Victron MPPT 75/15 119 euros, 100Ah LiFePO4 499 euros, roof mounting kit (6 brackets, 6m cable, cable entry) 149 euros, battery cables and fuse 51 euros. With 200Wp and 150Ah you are at 1497 euros. Compared with the campsite fee of an average 12 euros per night with mains hook-up, the system pays for itself after about 125 days of free standing – less than one season for frequent travellers.
Is there also a solar set with a flexible module for curved roofs?
Yes, our 120Wp flex set with ETFE-coated module (2.5mm thin, 2.8 kg) adapts to roof curvatures up to 5 degrees and costs 389 euros. It bonds directly to the roof with 3M adhesive (primer included), without brackets or air gap. Disadvantage: less cooling than raised modules – at 45°C cell temperature, output drops by 0.35% per degree, so about 8% less yield in midsummer. The ETFE surface is self-cleaning and hail-resistant up to 25mm. The flex module has a 25-year performance guarantee with max. 0.8% degradation per year. Includes MPPT controller, do not operate with PWM, as the module voltage is 21V.
How quickly does electronicx deliver and what does shipping cost?
Standard delivery within Germany: 1–2 working days, free shipping via DHL. Our batteries and solar modules leave the warehouse in Cleebronn (Hindenburgstr. 37A, 74389) Monday to Friday by 2 pm. Personal collection by prior appointment on +49 7135 7194106 is free – we will then advise you directly on site.
Which adapters for the solar connection are available at electronicx?
We stock MC4-to-MC4 extensions in 3, 6 and 10 metres for 14.90 to 34.90 euros. Special adapters: MC4 to Anderson SB50 (29 euros) for Goal Zero power stations, MC4 to 8mm DC hollow plug (19.90 euros) for Jackery, MC4 to SAE plug (12.90 euros) for older CTEK chargers. Our Y-distributor pair (parallel) for 24.90 euros connects two modules into one string. The polarity reverser adapter (9.90 euros) corrects incorrectly polarised connections. All plugs are moulded and UV-resistant with silicone seal – the contacts gold-plated for minimal contact resistance below 0.2 mOhm.
Can I place an order by phone or email?
Of course. You can reach us by telephone on +49 7135 7194106 Monday to Friday from 7:00 to 15:30. Our technical advisers help with putting together the optimum solar set – this is often quicker than the online configurator. By email to [email protected] you will receive a quote with all the technical details within 2 hours. Many campers value the personal advice on cable cross-sections and module sizes. When ordering by telephone you pay as in the shop by invoice, PayPal or credit card. The purchase process then runs as usual via our secure TLS 1.3 encrypted system.
Does a 120 watt solar module fit on a VW Bus T6 California?
Yes, our 120Wp module measuring 1480x670mm fits perfectly on the T6 California pop-up roof between the rails. Mount it with the supplied Z-brackets (4 pieces, height-adjustable 20-40mm) and Sikaflex adhesive. The module weighs 8.2 kg – the California roof carries 50 kg dynamically. Note the air gap of 3 cm to the roof skin for cooling. The MPPT controller fits in the wardrobe at the rear left. The cable routing through the existing cable gland of the rail is sealed and waterproof with our 10mm rubber grommet set (19.90 Euro). Allow 4 hours installation time including wiring to the battery under the driver's seat.
Which payment methods does electronicx accept?
We accept PayPal, credit card (Visa, Mastercard, Amex), advance payment (2% discount), instant transfer and invoice purchase via Klarna (30 days payment term). The latter is possible for camping solar sets up to 2500 Euro and is activated after a credit check. For collection in Cleebronn you can pay in cash or by debit card. Business customers with a valid VAT ID receive a net invoice. Payment processing is SSL encrypted, credit card details are not stored by us. For advance payment we ship immediately after receipt of payment.
Does electronicx offer an installation service for solar systems in motorhomes?
We do not offer our own installation service, but recommend vetted partners in your region. On request to [email protected] we will send a list of 12 motorhome workshops throughout Germany that install our sets. The cost of installing a 120Wp set including wiring and commissioning is between 300 and 450 Euro net, depending on roof accessibility and battery position. For DIY installers we have a detailed video guide with a running time of 47 minutes and a step-by-step PDF on our website.