MK Battery

M40 12V 40AH GEL Battery ( Sold in pairs )

Mobility Batteries
(Model No. M40-12 SLD G)

Starting at: $469.99 USD

Key Features

    • Deep Cycle Performance: Capable of up to 1,000 cycles at 50% Depth of Discharge (DOD), offering significantly longer life (averaging 1 to 2 years) compared to standard AGM batteries.
    • Sealed Gel Technology: Uses a thixotropic gel electrolyte that is completely immobilized, making it leak-proof and spill-proof.
    • Maintenance-Free: A completely sealed VRLA (Valve-Regulated Lead-Acid) design that never requires water refills.
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MK Battery

Mobility Batteries
(Model No. M40-12 SLD G)

Starting at: $469.99 USD
$469.99
Shipping calculated at checkout.

Description
Specifications
Information

MK Battery M40-12 SLD G 12V 40Ah Gel Batteries, Pair

This listing supplies two MK Battery M40-12 SLD G batteries. Each battery is rated at 12 volts and 40 amp-hours and uses sealed gel chemistry with immobilized electrolyte. Gel and AGM batteries are different constructions; the M40 should be selected only when the equipment manufacturer specifies this gel model or confirms it as a compatible replacement. The pair's system voltage and amp-hour capacity depend on the device's wiring.

Confirm Fit and Battery Count

Check that the equipment calls for two M40-12 SLD G batteries and compare the case size, tray, terminals, cable orientation and hold-downs with the existing installation. A matching 12V rating does not make another battery model or chemistry interchangeable. Confirm the full model code and required battery count before ordering.

Gel Charging and Maintenance

MK describes its sealed gel batteries as valve-regulated and maintenance-free, with no routine watering. The device still needs a charger profile appropriate for gel chemistry. Verify charger and equipment compatibility before installation, and follow the battery and device manuals for wiring, polarity, charging, storage and handling. Do not substitute the M22NF AGM model or another battery type by group size alone.

Pair Quantity and Installation Service

This product is sold as a pair for equipment that specifies two batteries. The 12V/40Ah label applies to each unit; the assembled system's voltage and capacity depend on the series or parallel connection. Optional installation service is labor dispatch and battery installation only, is non-refundable and may involve a distance-based charge. Confirm the service area before selecting it.

Before Ordering

Verify the exact M40-12 SLD G model, pair quantity, per-battery 12V/40Ah rating, gel chemistry, terminal layout, tray clearance and charger profile. Match the device manufacturer's specification before replacing the existing set.

GEL Battery

  • Capacity at 5hr RATE 34AH
  • Capacity at 20hr RATE 40AH
  • Capacity at 100hr RATE 48AH

Dimensions:

  • Weight: 32 lbs each
  • Length: 7.76'
  • Width: 6.62'
  • Height: 6.87'

GEL vs. AGM Sealed Batteries

AGM (absorbed glass mat) is a special design glass mat designed to wick the battery electrolyte between the battery plates. AGM batteries contain only enough liquid to keep the mat wet with the electrolyte and if the battery is broken no free liquid is available to leak out.

Gel Cell batteries contain a silica type gel that the battery electrolyte is suspended in, this thick paste like material allows electrons to flow between plates but will not leak from the battery if the case is broken.

More often than not an AGM Batteries are mistakenly identified as a Gel Cell Batteries. Both batteries have similar traits; such as being non spillable, deep cycle, may be mounted in any position, low self discharge, safe for use in limited ventilation areas, and may be transported via Air or Ground safely without special handling.

AGM Batteries outsell Gel Cell by at least a 100 to 1. AGM is preferred when a high burst of amps may be required. In most cases recharge can be accomplished by using a good quality standard battery charger or engine alternator. The life expectancy; measured as cycle life or years remains excellent in most AGM batteries if the batteries are not discharged more than 60% between recharge.

Gel Cell Batteries are typically a bit more costly and do not offer the same power capacity as do the same physical size AGM battery. The Gel Cell excels in slow discharge rates and slightly higher ambient operating temperatures. One big issue with Gel Batteries that must be addressing is the CHARGE PROFILE. Gel Cell Batteries must be recharged correctly or the battery will suffer premature failure. The battery charger being used to recharge the battery(s) must be designed or adjustable for Gel Cell Batteries. If you are using an alternator to recharge a true Gel Cell a special regulator must be installed.

If you are unsure which battery or charger is best for your application, please call or email our tech people for help making the correct selection.
Ownership Information:

No product documentation available at this time.

Warranty Information:

12 Month Full Replacement Warranty with Receipt

Shipping / Returns Information:

No shipping/returns information available at this time.