# MK Battery 8G40 · Electric wheelchair battery 12V 40Ah

![MK Battery 8G40 · Electric wheelchair battery 12V 40Ah](https://bateriasonline.es/2824-home_default/mk-battery-8g40.jpg)

> MK Battery 8G40: 40 Ah electric wheelchair battery, 197.1×168.1×174.8 mm, GEL. Equivalent to Deka 8G40 and Long LG40-12. Ask for a no-obligation quote.

**Category:** [Electric wheelchair batteries](https://bateriasonline.es/en/electric-wheelchair-batteries) → [MK Battery](https://bateriasonline.es/en/mk-batteries)

- **Canonical URL**: https://bateriasonline.es/en/mk-battery-8g40
- **Language**: en
- **Brand**: MK Battery
- **Reference**: BOL-MK-8G40
- **MPN**: 8G40
- **Last updated**: 2026-11-06

## Technical specifications

| Feature | Value |
|---|---|
| Brand | MK Battery |
| Range | MK GEL |
| Application | Electric wheelchairs |
| Technology | GEL |
| Voltage | 12 V |
| Capacity | 40 Ah |
| Length | 197.1 mm |
| Width | 168.1 mm |
| Height | 174.8 mm |
| Weight | 14.29 kg |

## Quick description

The MK Battery 8G40 is an electric wheelchair battery with 12 V and 40 Ah, measuring 197.1 × 168.1 × 174.8 mm.

## Description

## Where the MK Battery 8G40 fits

The MK Battery 8G40 is a deep-cycle battery for electric wheelchairs: sealed, maintenance-free and built to discharge and recharge every day without losing capacity. The 8G40 is fitted in pairs: two 12 V batteries in series give the chair's 24 V.
The 8G40 belongs to the MK Battery MK GEL range. [More MK Battery batteries](https://bateriasonline.es/en/mk-batteries)

## Equivalents and alternatives to the MK Battery 8G40

Other gel batteries with the dimensions and polarity of the 8G40: with gel it is best to stay with gel, because the charging profile is different.

| Model | Technology | Capacity | Dimensions (mm) |
|---|---|---|---|
| Deka 8G40 | GEL | 40 Ah | 197.1 × 168.1 × 174.8 |
| Long LG40-12 | GEL | 40 Ah | 199 × 166 × 171 |
| Long LG40-12N | GEL | 40 Ah | 199 × 166 × 171 |
| MK Battery M40-12 SLD G | GEL | 40 Ah | 197.1 × 168.1 × 174.8 |

## MK Battery 8G40 vs 8GU1 and MU-1 SLD G: differences

Torn between the 8G40 and another similar MK Battery? This is what changes:

| Model | Capacity | Dimensions (mm) | Weight |
|---|---|---|---|
| MK Battery 8G40 (this one) | 40 Ah | 197.1 × 168.1 × 174.8 | 14.29 kg |
| MK Battery 8GU1 | 31.6 Ah | 195.8 × 131.6 × 183.4 | 10.66 kg |
| MK Battery MU-1 SLD G | 31.6 Ah | 195.8 × 131.6 × 183.4 | 10.66 kg |

- MK Battery 8GU1: 8.40 Ah less, a different case (195.8 × 131.6 × 183.4 mm).
- MK Battery MU-1 SLD G: 8.40 Ah less, a different case (195.8 × 131.6 × 183.4 mm).

## What it means that the 8G40 is GEL

The 8G40 is a gel battery: the electrolyte is immobilised in silica gel. The 8G40 handles repeated deep discharges well, its strong point compared with an AGM.

## Check this before ordering the MK Battery 8G40

- The 8G40 needs 197.1 × 168.1 × 174.8 mm of space: measure it with the hold-down clamp in place.
- With 40 Ah, the 8G40 replaces an original battery of that capacity or slightly less.

## MK Battery 8G40 codes and part numbers

Look for any of these 8G40 codes on your current battery or in the manufacturer's catalogue:

| Commercial reference | 8G40 |
|---|---|
| Not to be confused with | MK Battery 8G4D (183 Ah) |

## Frequently asked questions about the MK Battery 8G40

### MK Battery 8G40 or 8GU1?

Compared with the 8G40, the MK Battery 8GU1 has 8.40 Ah less. With 40 Ah, the 8G40 runs longer between charges than the 8GU1 (31.6 Ah). Mind the space: the 8GU1 measures 195.8 × 131.6 × 183.4 mm.

### How much does the MK Battery 8G40 weigh?

The 8G40 weighs 14.29 kg. For reference, the MK Battery 8GU1 (31.6 Ah) weighs 10.66 kg.

### Which battery is equivalent to the MK Battery 8G40?

For the 8G40, other gel batteries with its size and polarity: Deka 8G40, Long LG40-12 and Long LG40-12N.

### Which charger does the MK Battery 8G40 need?

A charger with a GEL mode not exceeding 14.1-14.4 V. Charging it with a conventional lead-acid profile damages it through overcharging.

## Other options if you are unsure about the 8G40

- [All electric wheelchair batteries](https://bateriasonline.es/en/electric-wheelchair-batteries)
- [The whole MK Battery range](https://bateriasonline.es/en/mk-batteries)
- [Deka 8G40](https://bateriasonline.es/en/deka-8g40) · 40 Ah, 197.1×168.1×174.8 mm
- [Long LG40-12](https://bateriasonline.es/en/long-lg40-12) · 40 Ah, 199×166×171 mm

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*bateriasonline.es — Batteries and accessories · 2026-11-10*