# Long LG40-12 · Electric wheelchair battery 12V 40Ah

![Long LG40-12 · Electric wheelchair battery 12V 40Ah](https://bateriasonline.es/870-home_default/long-lg40-12.jpg)

> Long LG40-12: 40 Ah electric wheelchair battery, 199×166×171 mm, positive terminal on the right, GEL. Equivalent to MK Battery 8G40.

**Category:** [Electric wheelchair batteries](https://bateriasonline.es/en/electric-wheelchair-batteries) → [Long](https://bateriasonline.es/en/long-batteries)

- **Canonical URL**: https://bateriasonline.es/en/long-lg40-12
- **Language**: en
- **Brand**: Long
- **Reference**: BOL-LONG-LG40-12
- **MPN**: LG40-12
- **Price**: 185,53 € (VAT incl., Spain)
- **Last updated**: 2026-11-06

## Technical specifications

| Feature | Value |
|---|---|
| Brand | Long |
| Range | LG Series |
| Application | Electric wheelchairs |
| Technology | GEL |
| Voltage | 12 V |
| Capacity | 40 Ah |
| Length | 199 mm |
| Width | 166 mm |
| Height | 171 mm |
| Weight | 13.3 kg |
| Polarity | Positive terminal on the right |

## Quick description

The Long LG40-12 is an electric wheelchair battery with 12 V and 40 Ah, measuring 199 × 166 × 171 mm, with the positive terminal on the right.

## Description

## Who the Long LG40-12 is for

The Long LG40-12 is a deep-cycle battery for electric wheelchairs: sealed, maintenance-free and built to discharge and recharge every day without losing capacity. It is fitted as a 12 V pair and takes hundreds of daily cycles, something a starter battery could not handle.
The LG40-12 belongs to the Long LG Series range. [More Long batteries](https://bateriasonline.es/en/long-batteries)

## Inside the LG40-12: GEL technology

The LG40-12 is a gel battery: the electrolyte is immobilised in silica gel. It requires a charger with a specific gel profile.

## Long LG40-12 vs LG45-12 and LG45-12N

Torn between the LG40-12 and another similar Long? This is what changes:

| Model | Capacity | Dimensions (mm) | Positive | Weight |
|---|---|---|---|---|
| Long LG40-12 (this one) | 40 Ah | 199 × 166 × 171 | right | 13.3 kg |
| Long LG45-12 | 45 Ah | 199 × 166 × 171 | right | 15 kg |
| Long LG45-12N | 45 Ah | 199 × 166 × 171 | right | 15 kg |

- Long LG45-12: 5 Ah more, the same dimensions.
- Long LG45-12N: 5 Ah more, the same dimensions.

## Equivalents and alternatives to the Long LG40-12

Other gel batteries with the dimensions and polarity of the LG40-12: with gel it is best to stay with gel, because the charging profile is different.

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

## Long LG40-12 codes and part numbers

The LG40-12 is listed under these codes on labels, in garages and in catalogues:

| Commercial reference | LG40-12 |
|---|---|
| Not to be confused with | Long LG45-12 (45 Ah), Long LG50-12 (50 Ah) |

## What to look at before buying the LG40-12

- With 40 Ah, the LG40-12 replaces an original battery of that capacity or slightly less.
- With the terminals facing you, the positive terminal of the LG40-12 is on the right.
- The LG40-12 needs 199 × 166 × 171 mm of space: measure it with the hold-down clamp in place.

## Frequently asked questions about the Long LG40-12

### Long LG40-12 or LG45-12?

Compared with the LG40-12, the Long LG45-12 has 5 Ah more. With 45 Ah, the LG45-12 runs longer between charges than the LG40-12 (40 Ah). Both measure 199 × 166 × 171 mm, so they fit the same tray.

### How much does the Long LG40-12 weigh?

The LG40-12 weighs 13.3 kg. For reference, the Long LG45-12 (45 Ah) weighs 15 kg.

### Which battery is equivalent to the Long LG40-12?

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

### Which side is the positive terminal on the Long LG40-12?

The LG40-12 has the positive terminal on the right, looking at the battery from its long side with the terminals closest to you.

### Which charger does the Long LG40-12 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.

## Keep comparing: alternatives to the LG40-12

- [More electric wheelchair batteries](https://bateriasonline.es/en/electric-wheelchair-batteries)
- [More Long models](https://bateriasonline.es/en/long-batteries)
- [MK Battery 8G40](https://bateriasonline.es/en/mk-battery-8g40) · 40 Ah, 197.1×168.1×174.8 mm
- [MK Battery M40-12 SLD G](https://bateriasonline.es/en/mk-battery-m40-12-sld-g) · 40 Ah, 197.1×168.1×174.8 mm

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