Drop in lithium deep cycle replacement leisure batteries

Leaders Lithium-ion Phosphate motor home & marine leisure batteries

12V Lithium-ion Phosphate Leisure Battery Technology


Our batteries return almost all stored energy at a constant voltage, which make them the perfect choice for leisure use. Especially where reliable off grid energy is desirable for power hungry devices such as inverters, satellite receivers and televisions. Whilst this characteristic is highly desirable for any energy source, it presents a challenge for voltage based energy gauging. We integrate a voltage and temperature gauge in all our batteries however it should be noted that there can be a 15% error tolerance of capacity as it can only ever be a approximation (for this reason we do not offer a blue tooth derivative of this gauge). The correct method for gauging capacity is a method know as coulomb counting and we can supply this solution if required. Customers are reminded to pay attention to the maximum current rating of their selected battery and parallel accordingly for very high current inverters.

Our batteries all feature M8 terminals connection poles and are supplied with extra depth bolts and spring and flat washers. Each battery is also supplied with a detachable carry strap and a integral voltage/temperature gauge. All batteries are manufactured with a integral advanced battery management system.


 Unlike Lithium polymer batteries (LiPo), used in mobile phones and electric vehicles, LiFePo4 have a wider charge/ discharge tolerance. Under severe stress conditions including cell short circuit, the electrolyte reaction creates lower exothermic heat output. This means thermal runaway is not possible. This renders fire risk almost impossible and crucially there's no explosive gases.  Our batteries are CE certified and the cells are tested to UN38.3 specification. This assures KS Energy batteries not only meet, but exceed the requirements for EMC, health, safety, and environmental standards across UK and Europe.

UN38.3 certified (Land, Sea, Aviation)


KS Energy batteries are now at a  price point where lifespan ( >5000 cycles @80% - 30% DOD 0.5C, >2500 cycles DOD 95% 1C), energy density, weight and safety trounces all conventional lead technologies. Lithium-iron phosphate (developed in 1996) is becoming the choice of battery chemistry replacing lead (Pb) acid battery formats, including GEL and AGM. LiFePo4 is roughly four times the energy density of Pb. Since the entire charge is available, it is often thought as being twice as efficient as a similar rated lead acid battery. This means that at 8Ah/Kg density, it can result in a physical weight saving of around four times which also reduces a motorhome axle weight.


  KS Energy batteries are Guaranteed for 10 years from your date of purchase. Under normal use, the usable lifespan of our leisure batteries offer a typical cycle life of 5000 cycles (80% - 30% DOD @0.15C discharge) which in excess of 15 years daily use.

Stability: Our batteries are constructed from GSL 26650 3.2V 3.2Ah Lithium-ion Phosphate individual cells which are packaged in plated cylindrical steel canisters. Between each cell group we integrate a unique cell management system. Our integrated cell management system ensures each cell always functions at its optimum, both during charge and discharge. Many inferior LiFePo4 12V batteries will be constructed from Prismatic cells, which are not mechanically stable, particularly when used to extremes. For this reason KS Energy batteries only use cylindrical 26650 cells.

Life:  These batteries are among the longest lived and safest batteries ever developed. Test data in the laboratory points to well in excess of 5000 cycles from 80 to 30% and over 3000 from 80% to 0% charge/discharge cycles. This is due to the extremely robust crystal structure of the iron phosphate, which does not break down under repeated packing and unpacking of the lithium ions during charging and discharging including fast forced charging. Shallower cycles result in numbers approaching 4000 cycles (in excess of 10 years serviceable life.

Energy Density: This technology not only has a very high energy density but delivers high power for longer. Lithium cells can supply power to near zero capacity before cell voltage significantly tails off This means they can deliver nearly 100% of their stored energy. Moreover Lithium cells are perfectly happy operating in this way. Conventional Pb batteries suffer sever degradation once around 50% of the power has been delivered and significantly shortened life spans (<30 cycles typical), even worse cell voltage tails off meaning the stored energy is never practically accessible. For this reason a 100AH rated lithium battery may often be regarded as the equivalent of a 200AH lead acid battery!

Environmental Impact: KS Energy only manufacture LiFePo4 batteries and our batteries have dramatically reduced environmental impacts. Compared to lead battery chemistry, there is no highly toxic and environmental contaminating lead. The chemical elements in our batteries simply become inert upon recycling. Moreover the useful working life span can be more than 8 times that of a lead acid battery so that the ongoing carbon foot print of manufacturing reduces like for like

Simplified Charging: In addition, since cell voltage tolerance is wider and impedance lower, LiFEPo4 batteries can accept a higher constant current charge resulting in faster charge times and since internal discharge minute, there is no requirement for trickle charging either. All KS Energy batteries incorporate cutting edge individual cell management circuit boards with LCD (optional blue tooth) charge control indicator.