# Wheelchair battery MK Powered 8G40 12V 40Ah GEL ![Wheelchair battery MK Powered 8G40 12V 40Ah GEL](https://baterias.com/196-home_default/battery-mk-8g40-12v-40ah.jpg) > MK Powered 8G40 wheelchair battery 12V 40Ah GEL. Dimensions 197Γ—168Γ—174 mm. Deep-cycle and sealed, for daily wheelchair and mobility scooter use. **Category:** [Power Wheelchair Batteries](https://baterias.com/gb/batteries-for-electric-wheelchairs) β†’ [MK POWERED](https://baterias.com/gb/mk-powered) - **Canonical URL**: https://baterias.com/gb/battery-mk-8g40-12v-40ah - **Language**: en-GB - **Brand**: MK POWERED - **Reference**: BCOM-MK-8G40 - **MPN**: 8G40 - **Stock**: Out of stock ## Technical specifications | Feature | Value | |---|---| | Brand | MK | | Reference | 8G40 | | Model | MK GEL | | Voltage (V) | 12 V | | Largo | 197.1 mm | | Ancho | 168.1 mm | | Alto | 174.8 mm | | Peso | 14.29 kg | | TecnologΓ­a | GEL | | Capacity (C20) | 40 Ah (c20) | | Capacity (C10) | 68 Ah (c10) | | Capacity (C5) | 34 Ah (c5) | ## Quick description **MK Powered 8G40 12V 40Ah** is a sealed AGM/GEL battery for daily mobility use: maintenance-free, no risk of spills, and thousands of useful cycles well beyond a starter battery. ## Why this wheelchair battery? - **Daily cycling without wear** handles deep discharges without losing capacity - **Sealed AGM/GEL** no maintenance, no risk of spills - **Thousands of useful cycles** over its full lifetime πŸ”Œ Voltage 12 V ⚑ Capacity 40 Ah C20 πŸ“ Dimensions 197Γ—168Γ—174 mm βš™οΈ Technology GEL βš–οΈ Weight 14,29 kg 🏷️ Model MK GEL ## Description ## Mobility battery MK Powered 8G40 Mk GEL 40Ah 12V 12*V* Voltage 40*Ah* Capacity 14.29*kg* Weight The **12 V**, **40 Ah** **MK Powered 8G40** from the **Mk GEL** range with GEL technology is the standard replacement for power wheelchairs, mobility scooters and light electric vehicles. Its 197 Γ— 168 Γ— 174 mm make it the exact replacement for the 40 Ah battery fitted as standard to many power wheelchairs and mobility scooters. - Sealed AGM/GEL: safe indoors and in transport. - GEL: excellent resistance to deep discharge and long cycle life. - Approved for air and sea transport (VRLA). - No maintenance, no water top-ups. ### What the MK Powered 8G40 is for The MK Powered 8G40 is the usual replacement in power wheelchairs, mobility scooters and light electric vehicles. Recharge after each use and avoid leaving it discharged for days. Check that it matches your current battery in dimensions, terminals and hold-down: this reference has a weight of 14.29 kg. ### Dimensions, polarity and mounting It has external dimensions of 197 Γ— 168 Γ— 174 mm and weighs 14.29 kg. For a direct replacement, the current battery tray must accept these dimensions and the same terminal layout; otherwise adapters will be needed or the hold-down will change. ### What MK Powered does differently MK batteries are the standard in the electric mobility sector: sealed, approved for air transport and with the consistency that wheelchair manufacturers demand as original equipment. We guarantee that every MK Powered arrives new, charged and with the manufacturer's full warranty. ### The MK Powered 8G40: Mk GEL range and GEL technology The **Mk GEL** is the MK Powered range the 8G40 belongs to: it shares the same construction and quality criteria with the rest of the series, and varies in capacity and format to suit each vehicle. 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. ### How to make it last longer GEL batteries need lower charging voltages: always use a charger with a GEL mode so as not to damage the electrolyte. Recharge the wheelchair or scooter after each use and do not leave it discharged for days: lead sulphates and loses capacity. ### Official warranty The MK Powered 8G40 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. ### Shipping, delivery and returns Same-day dispatch from our warehouse for in-stock orders placed **before [[ks:cutoff]]**: 24-48 working hours in mainland Spain and Portugal, 3 to 5 days in the islands and the rest of Europe. Returns are accepted for **[[ks:return_days]] days** if the battery has not been used (free collection on the Iberian mainland). You will receive tracking by email. ## Frequently asked questions ### Is the MK Powered 8G40 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 β€” max charge voltage ~14.1 V (vs 14.4-14.7 V for AGM). Lifespan 6-10 years. ### How do I fit the 8G40 model in my device? 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 this page. 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 (βˆ’) 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 β€” match the polarity shown on the product sheet; 6) connect the positive (+) first, then the negative (βˆ’). On devices with Start-Stop or BMS, register the battery via OBD so the alternator applies the correct charging profile. ### How long does the MK Powered 8G40 battery last? Expected lifespan of the MK Powered 8G40 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 MK Powered 8G40 battery? Dimensions (length Γ— width Γ— height) are 197Γ—168Γ—175 mm β€” also written as 197x168x175 mm β€” 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. ### Which batteries are equivalent to the MK Powered 8G40? 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 β€” 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. ## Reviews - **Average rating**: 4.74 / 5 (52 reviews) ## Technical team (editorial authorship) The FAQs, guides and comparisons on this site are reviewed by the baterias.com technical team β€” over 25 years of experience validating automotive batteries. β†’ https://baterias.com/gb/technical-team --- *baterias.com β€” Automotive batteries Β· 2026-10-05*