# MK Battery M40-12 SLD G · Electric wheelchair battery 12V 40Ah

![MK Battery M40-12 SLD G · Electric wheelchair battery 12V 40Ah](https://bateriasonline.es/3592-home_default/mk-battery-m40-12-sld-g.jpg)

> MK Battery M40-12 SLD G: 40 Ah electric wheelchair battery, 197.1×168.1×174.8 mm, GEL. Equivalent to Deka 8G40 and Long LG40-12.

**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-m40-12-sld-g
- **Language**: en
- **Brand**: MK Battery
- **Reference**: BOL-MK-M40-12 SLD G
- **EAN**: 3660766462596
- **MPN**: M40-12 SLD G
- **Price**: 176,91 € (VAT incl., Spain)
- **Last updated**: 2026-10-27

## 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 |
| Terminal type | C (INSERT) |

## Quick description

The MK Battery M40-12 SLD G is an electric wheelchair battery with 12 V and 40 Ah, measuring 197.1 × 168.1 × 174.8 mm.

## Description

## Who the MK Battery M40-12 SLD G is for

The MK Battery M40-12 SLD G is a deep-cycle battery for electric wheelchairs: sealed, maintenance-free and built to discharge and recharge every day without losing capacity. With 40 Ah per battery, the M40-12 SLD G is designed for a full charge every night.
The M40-12 SLD G belongs to the MK Battery MK GEL range. [See all MK Battery batteries](https://bateriasonline.es/en/mk-batteries)

## Inside the M40-12 SLD G: GEL technology

The M40-12 SLD G is a gel battery: the electrolyte is immobilised in silica gel. It requires a charger with a specific gel profile.

## MK Battery M40-12 SLD G vs 8GU1 and MU-1 SLD G

How the M40-12 SLD G compares with MK Battery batteries of similar size and capacity:

| Model | Capacity | Dimensions (mm) | Weight |
|---|---|---|---|
| MK Battery M40-12 SLD G (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).

## Equivalents and alternatives to the MK Battery M40-12 SLD G

Other gel batteries with the dimensions and polarity of the M40-12 SLD G: 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 8G40 | GEL | 40 Ah | 197.1 × 168.1 × 174.8 |

## MK Battery M40-12 SLD G codes and part numbers

The M40-12 SLD G is listed under these codes on labels, in garages and in catalogues:

| Commercial reference | M40-12 SLD G |
|---|---|
| EAN | 3660766462596 |
| Terminal type | C (INSERT) |
| Not to be confused with | MK Battery M40-12 SLD M (45 Ah) |

## Before ordering the M40-12 SLD G, check this

- Capacity of the M40-12 SLD G: 40 Ah; the same as your current battery or slightly more is fine.
- The M40-12 SLD G needs 197.1 × 168.1 × 174.8 mm of space: measure it with the hold-down clamp in place.

## Frequently asked questions about the MK Battery M40-12 SLD G

### MK Battery M40-12 SLD G or 8GU1?

Compared with the M40-12 SLD G, the MK Battery 8GU1 has 8.40 Ah less. With 40 Ah, the M40-12 SLD G 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 M40-12 SLD G weigh?

The M40-12 SLD G 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 M40-12 SLD G?

For the M40-12 SLD G, other gel batteries with its size and polarity: Deka 8G40, Long LG40-12 and Long LG40-12N.

### Do I have to replace both batteries at once?

Yes. Wheelchairs fit two batteries in series, and a new one next to a worn one becomes unbalanced and lasts much less.

## More batteries to compare with the M40-12 SLD G

- [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 · 2026-11-11*