These new Lithium-Ion, LiFePO4 batteries are an ideal replacement for many 12V and 24V caravan, motorhome, work vans and similar battery applications.

Let’s look at a typical van or motorhome which may have a 110Ah to 220Ah lead-acid leisure battery for light loads such as lighting, laptops, phones, powering a diesel heater, a 12v compressor fridge etc maybe a small inverter to0.  Maybe you’ll have in around 100 to 200W of solar panels too using a small charge controller.

Regardless of the use, whichever SuperPack you choose it’ll be lighter than lead, can be smaller if you wish or give you more Wh in the same space – plus give you around 5 times the cycle life.

The main difference to Victron’s other lithium offerings are the SuperPacks keep everything in one package, by having an integrated BMS and safety switch built-in. No additional components are needed as the internal switch will disconnect the battery in case of over-discharge, overcharge or high temperature. Simple, compact and safe.

If you are considering a new battery don’t immediately discount Lithium as being too costly. Whilst it is true that the initial cost of Li-ion is greater than that of quality AGM or Gel batteries – it is also true that the cost of ownership can be less than lead-acid types. Much depends on your application, but rest assured – life with Li-ion is far less hassle than lead.

When it comes to replacing lead-acid type batteries such as AGM and Gel in many applications, the SuperPack range can be considered the next generation after lead – making it far easier to replace lead with lithium. The only caveats being replacement is down to certain parameters being met, namely – Capacity (Ah), Voltages (12.8V & 25.6V), Discharge and Charge currents. Do in that case be sure that your chosen replacement fits your criteria by checking the datasheet and be aware the SuperPacks can be connected in parallel, but not in series.

The Lithium SuperPack

Victron Energy’s recently introduced Lithium SuperPack range comes in the following capacities and voltages:

These SuperPacks will give you 2,500 cycles to 80% depth of discharge at 25°C, much more than lead.

Comparison: SuperPack 60Ah LiFePO4 vs 90Ah AGM

Let’s compare the 60Ah Li-ion to say a typical 100Ah AGM battery discharged to the commonly accepted economic cycle life of 50% discharge for lead-acid. That would give us 600 cycles at that DOD for the AGM compared to 2,500 at the even deeper discharge of 80% for the LiFePO4. Already you can see you may need to replace your lead-acid type battery 2 to 4 times as often as the Lithium. Of course loads, operating conditions and calendar life have to be factored in too. Regardless you get the idea – Lithium does more and lasts longer.

60Ah SuperPack 100Ah AGM
Weight 9.5kg 21kg
Size 229 x 138 x 213 360 x 130 x 190
Useable energy @ 25°C 614Wh 600Wh
Cycle Life 2500 Cycles 600 Cycles
Cost 3.3 times £559 £169

Other factors to consider

Is the above enough to convince you of why Lithium might be a better alternative than AGM or indeed Gel? Personally I’m sold on Lithium, but if you are not here’s a few things further to consider:

  1. A lead-acid battery will fail prematurely due to sulfation if it operates in deficit mode for long periods of time (i.e. if the battery is rarely, or never at all, fully charged). It will also fail early if left partially charged or worse, fully discharged.
  2. By comparison, a Lithium-Ion battery does not need to be fully charged. This is a major advantage of Li-ion compared to lead-acid which needs to be fully charged often to prevent sulfation.
  3. Efficiency. In several applications (especially off-grid solar), energy efficiency can be of crucial importance. The round-trip energy efficiency (discharge from 100% to 0% and back to 100% charged) of the average lead-acid battery is 80%.
  4. The round-trip energy efficiency of a Li-ion battery is 92%.
  5. The charge process of lead-acid batteries becomes particularly inefficient when the 80% state of charge has been reached, resulting in efficiencies of 50% or even less in solar systems where several days of reserve energy are required (battery operating in 70% to 100% charged state).
  6. In contrast, a Li-ion battery will still achieve 90% efficiency even under shallow discharge conditions.

Downsides

Not wanting to sound too evangelical, we also need to consider the few downsides of Li-ion.

  • Higher upfront cost and to some extent higher capital risk.
  • Charging is restricted to the +5°C to +45° range, subject to an internal means of blocking the charge source when the temperature is below +5°C. Note this is currently automatically possible with Victron MPPTs when used in conjunction with the Smart Battery Sense for instance.
  • The SuperPack (unlike other Victron Lithiums) is not designed for series connections.

Content originally posted here