# How many amp hours does your campervan or motorhome battery need? A step-by-step calculation > Blog article — Málaga Baterías · Updated 2026-10-12 _Work out the Ah for your campervan or motorhome leisure battery: consumption table, three worked examples and AGM or lithium. Get a quote in Málaga._ It’s the question we hear most at the counter from people travelling by campervan, motorhome or caravan around Málaga and the Costa del Sol : “How many amp hours should my leisure battery be?” There is no single figure that suits everyone, but there is a sum you can do in ten minutes. Here it is step by step, with a table of typical consumption and three worked examples. Quick answer: add up what each appliance uses in a day ( watts ÷ 12 V × hours of use = Ah ), multiply by the number of days you want to last without recharging and divide by the usable share of the battery: half for lead-acid and AGM , around 80-90 % for lithium . A simple weekend away usually calls for 70-80 Ah of AGM; a trip with a compressor fridge, about 150 Ah of lithium or 260 Ah of AGM. The method: add up what you use in a day Battery capacity is measured in amp hours (Ah), while your appliances state their consumption in watts (W). Getting from one to the other takes a single division: Ah = W ÷ 12 V × hours of use . A 12 W LED strip left on for 4 hours uses 12 ÷ 12 × 4 = 4 Ah. The sum in four steps Do it with your appliances’ rating labels in front of you. - 01 Note the watts of each appliance - 02 Divide by 12 and multiply by the hours - 03 Add up the Ah for the whole day - 04 Apply days of autonomy and usable share If an appliance runs at 230 V through an inverter, the sum is the same, but add 10 to 15 % for the losses of the inverter itself. Typical consumption by appliance This table gives you a first estimate at 12 V. These are ballpark figures : the number that counts is the one on each appliance’s label or in its manual. Appliance Approximate consumption Typical hours Ah per day Compressor fridge 40-50 W with the compressor running 8-10 h of compressor time 25-40 Ah LED lights 10-20 W in total 4 h 3-7 Ah Water pump 40-60 W 15-20 min 1-2 Ah Diesel or gas heater (fan and control unit) 10-30 W once running 8 h 7-20 Ah Charging two phones 10-15 W each 1-2 h 2-4 Ah Charging a laptop 45-65 W 2 h 8-11 Ah Roof fan 15-30 W 6 h 8-15 Ah 12 V television 30-40 W 2 h 5-7 Ah The fridge is nearly always the biggest consumer, and in the summer heat in Málaga the compressor runs for more hours. A heater draws considerably more during start-up, even if only for a few minutes. Three worked examples 1. A weekend away with low consumption A simple campervan, a portable coolbox without a compressor and the bare essentials: LED lights (15 W × 4 h = 5 Ah), water pump (2 Ah), two phones (3 Ah) and the roof fan now and then (20 W × 4 h = 7 Ah). Total: about 17 Ah a day . 2. A trip with a compressor fridge A couple spending two weeks along the coast: compressor fridge (35 Ah), lights (5 Ah), pump (2 Ah), phones (3 Ah), laptop for two hours (10 Ah) and the roof fan at night (20 W × 6 h = 10 Ah). Total: about 65 Ah a day . 3. Living on board with an inverter A motorhome used as a home, working remotely: fridge (40 Ah), lights (7 Ah), pump (2 Ah), heating or ventilation (15 Ah), phones (3 Ah), television (6 Ah), laptop for four hours through the inverter (22 Ah including losses) and a 1,000 W coffee machine for six minutes (about 10 Ah). Total: about 105 Ah a day . Got your daily Ah? We’ll tell you which battery to fit Send us your consumption, how you recharge and the compartment dimensions on WhatsApp, or call us, and we’ll send you a quote. Call 952 31 01 18 WhatsApp From Ah used to Ah of battery What you use is not what you need to buy. No battery should be drained completely, and how much you can draw depends on the technology: - Lead-acid, EFB and AGM: count on around half of the capacity. Going below that as a habit shortens its life considerably. - Lithium: you can use the great majority , around 80-90 %, and it weighs a good deal less too. The full formula looks like this: battery Ah = daily Ah × days of autonomy ÷ usable share (0.5 for lead-acid and AGM; 0.85 for lithium). With two days without recharging, the three examples come out as follows: Example Ah per day Ah for 2 days AGM battery Lithium battery Weekend away 17 Ah 34 Ah 70-80 Ah 50 Ah Compressor fridge 65 Ah 130 Ah 260 Ah 150 Ah Living on board with an inverter 105 Ah 210 Ah 420 Ah 250 Ah Large capacities are achieved with one big battery or with two identical ones in parallel. And if you use an inverter, don’t look at the Ah alone: the battery also has to deliver the peak current it demands. Tell us the inverter’s power rating and we’ll check it. How it is recharged and why that changes the sum Days of autonomy are the days you spend with nothing going back in . If the battery is topped up every day, you need less capacity; if not, more. There are three routes: - Alternator with a DC-DC charger: charges while you drive. A 30 A charger puts back about 30 Ah per hour on the road. On vehicles with a smart alternator it is practically essential. - Solar panel: on the Costa del Sol it is your best ally. A 100 W panel can put back in the region of 25-30 Ah on a good sunny day; in winter or parked in the shade, a good deal less. - Campsite hook-up: with the mains charger you get back to 100 % while you are plugged in. If you drive every day or carry enough solar, you can size for a single day. If you stay put for a week without direct sun, for three or more. We explain it in leisure battery with a solar panel and in the guide to solar batteries . Which battery to fit: Varta ranges for campervans in Málaga and the Costa del Sol We are an Official Varta Distributor and these are the three ranges most often chosen for the living area: - Varta Professional Dual Purpose AGM: sealed, maintenance-free and vibration-resistant. For example, the 95 Ah Varta LA95 or the 210 Ah Varta LA210 . - Varta Professional Dual Purpose EFB: enhanced lead-acid that works for both starting and leisure use. There is the 140 Ah Varta LED140 and the 240 Ah Varta LED240 . … ## Buy or change this battery in Málaga Málaga Baterías — official Varta distributor. No appointment needed. Free quote and recycling of your old battery. - **Phone:** [952 31 01 18](tel:+34952310118) - **WhatsApp:** [+34 952 31 01 18](https://wa.me/34952310118) - **Address:** C/ La Orotava, 100, 29006 Málaga - **Directions:** https://maps.google.com/?q=Málaga+Baterías+C/+La+Orotava+100+Málaga ### Areas we cover Málaga city: Centro, Teatinos, El Palo, Pedregalejo, Ciudad Jardín, Cruz de Humilladero, Carretera de Cádiz, Churriana, Campanillas, Puerto de la Torre, Bailén-Miraflores, Palma-Palmilla. Costa del Sol: Torremolinos, Benalmádena, Fuengirola, Mijas, Marbella, Rincón de la Victoria, Vélez-Málaga, Torrox, Nerja, Alhaurín. --- [See the full product page](https://malagabaterias.com/en/blog/how-many-amp-hours-campervan-motorhome-battery)