# Solar battery Trojan 31-GEL 12V 102Ah GEL ![Solar battery Trojan 31-GEL 12V 102Ah GEL](https://baterias.com/685-home_default/battery-trojan-31-gel-12v.jpg) > Trojan 31-GEL solar battery 12V 102Ah GEL. Dimensions 329×171×245 mm. Designed for PV systems with daily cyclic loads. **Category:** [Batteries for Solar Applications](https://baterias.com/gb/batteries-for-solar-applications) → [TROJAN](https://baterias.com/gb/trojan) - **Canonical URL**: https://baterias.com/gb/battery-trojan-31-gel-12v - **Language**: en-GB - **Brand**: TROJAN - **Reference**: BCOM-TROJAN-31-GEL - **EAN**: 8404653001339 - **MPN**: 31-GEL - **Price**: 793,50 € - **Stock**: Out of stock ## Technical specifications | Feature | Value | |---|---| | Brand | TROJAN | | Reference | 31-GEL | | Model | TROJAN GEL | | Voltage (V) | 12 V | | Largo | 329 mm | | Ancho | 171 mm | | Alto | 245 mm | | Peso | 32 kg | | Tecnología | GEL | | Terminal type | 7 | | Capacity (C20) | 102 Ah (c20) | | Capacity (C5) | 85 Ah (c5) | ## Quick description **Trojan 31-GEL 12V 102Ah** is a solar battery designed for PV systems with daily charge/discharge cycles. Tolerates extreme temperatures well, with low self-discharge during winter shutdowns or between stays at vacation homes. ## Why this solar battery? - **Designed for solar systems** optimised for daily charge/discharge cycles - **Handles extreme temperatures** in technical rooms or outdoor installs - **Minimal self-discharge** when left idle over winter or holidays 🔌 Voltage 12 V ⚡ Capacity 102 Ah C20 📏 Dimensions 329×171×245 mm ⚙️ Technology GEL ⚖️ Weight 32 kg 🏷️ Model TROJAN GEL ## Description ## Solar battery Trojan 31-GEL 102Ah 12V 12*V* Voltage 102*Ah* Capacity 32*kg* Weight The **Trojan 31-GEL** with GEL technology stores **102 Ah** at **12 V** for off-grid photovoltaic installations and storage systems. It replaces the original battery without adaptation in off-grid PV systems with a 329 × 171 × 245 mm format: same 102 Ah capacity. - Good tolerance to extreme temperatures. - Long life on float and moderate cycling. - GEL technology: gelled electrolyte, fully sealed and maintenance-free. - Optimised for daily charge and discharge cycles. ### What the Trojan 31-GEL is for Designed for off-grid photovoltaic installations and storage systems, the Trojan 31-GEL tolerates extreme temperatures and long periods of low activity. Check that it matches your current battery in dimensions, terminals and hold-down: this reference has a weight of 32 kg and 7 terminals. ### Technology inside the Trojan 31-GEL Trojan builds the 31-GEL to the same standards as the rest of its catalogue; what changes between references is capacity, format and terminal position. In a GEL battery the electrolyte is gelled with silica: it is fully sealed, cannot spill and tolerates deep discharge very well. It is the preferred technology in electric mobility, marine service and heavy-cycling applications. ### Dimensions, polarity and mounting The Trojan 31-GEL is made in the 329 × 171 × 245 mm format and weighs 32 kg. It uses 7 terminals, the system that anchors and connects it in the vehicle. Checking the three dimensions and the terminal position before buying avoids the most common mistake when replacing a battery. ### What Trojan does differently Founded in 1925 in California, Trojan invented the golf cart battery and remains the standard in deep-discharge applications that demand thousands of cycles. We guarantee that every Trojan arrives new, charged and with the manufacturer's full warranty. ### Usage and maintenance tips In the darker months, check the voltage periodically and avoid full discharges. GEL batteries need lower charging voltages: always use a charger with a GEL mode so as not to damage the electrolyte. ### Warranty and coverage The Trojan 31-GEL comes with the **manufacturer's official warranty** against manufacturing defects. If it fails through a defect within the warranty period, we replace it at no cost to you. ### Delivery times and returns Order **before [[ks:cutoff]]** with stock available and it leaves today: mainland Spain and Portugal receive it in 24-48 working hours, the islands and the rest of the EU in 3 to 5 days. You have **[[ks:return_days]] days** to return it if it has not been installed, with free collection on the mainland, and shipment tracking by email. ## Frequently asked questions ### Is the Trojan 31-GEL a GEL battery? What is GEL used for? Yes, this model is a GEL battery: sealed lead-acid where the electrolyte is in gel form. It tolerates deep discharges very well and is ideal for cyclic use (solar, motorhomes, electric wheelchairs, motorcycles). Requires a GEL-specific smart charger — max charge voltage ~14.1 V (vs 14.4-14.7 V for AGM). Lifespan 6-10 years. ### How is the Trojan 31-GEL battery installed in the vehicle? In most devices it fits in 15-30 minutes with a 10 mm wrench; if the battery is under the seat or in the boot the time can double. See the step-by-step guide on our blog. Quick summary: 1) switch off the engine and remove the key; 2) locate the original battery (engine bay, boot or under seat); 3) disconnect the negative (−) terminal first, then the positive (+); 4) loosen the hold-down clamp and remove the old battery; 5) fit the new one in the same orientation — match the polarity shown on the product sheet; 6) connect the positive (+) first, then the negative (−). On devices with Start-Stop or BMS, register the battery via OBD so the alternator applies the correct charging profile. ### What is the service life of the 31-GEL model? Expected lifespan of the Trojan 31-GEL is 6 to 10 years in cyclic use (marine, caravan, solar) with controlled discharges. In cold regions it drops slightly due to cold-start stress; in very hot regions it also drops because of electrolyte evaporation. To extend its life: avoid deep discharges (headlights on with engine off), have the alternator checked yearly, and keep the battery clean and properly secured. ### What are the dimensions of the Trojan 31-GEL battery? Dimensions (length × width × height) are 329×171×245 mm — also written as 329x171x245 mm — following the European DIN standard. Always measure the space in your device before buying: even one extra millimetre can prevent the hold-down clamp from closing. The height shown includes the terminals. ### What are the equivalents of the 31-GEL model? Directly interchangeable batteries (same dimensions, same polarity, same Ah and CCA) are the OEM equivalents from leading brands: Bosch, Tudor, Exide and, depending on the model, Banner or Yuasa. Exact equivalence depends on technology — an EFB cannot be replaced with a conventional battery in Start-Stop devices. See the "Equivalents" section to view recommended options at the same performance level. ## Technical team (editorial authorship) The FAQs, guides and comparisons on this site are reviewed by the baterias.com technical team — automotive battery specialists since 2012. → https://baterias.com/gb/technical-team --- *baterias.com — Automotive batteries · 2026-10-19*