If you're planning to upgrade your system to Lithium batteries (LiFePO
4 or Lithium Iron Phosphate) the work starts before you purchase a battery.
While many battery sellers will market their battery as "suitable for all chargers" or straight swap for lead-acid batteries", this is not always the case.
It's important to note here that Caravan Electrical Solutions utilise Battery Management Systems in the van we work, not chargers. When referring to "chargers" it's generally meant something with 3-5 stages or so that charges the battery and has no other function.
Also, while these batteries may work with a number of simple chargers, they will not work with most displays or monitors which are not Lithium compatible. This is due to the charge voltage level, float level and rested level of the battery being vastly different from lead-acid batteries.
You also need to be aware of what you are using the batteries for and where they're to be installed. Check the specifications of the battery/s carefully to see if they are waterproof as this will dictate whether you can use your chassis-mounted battery boxes.
While you're checking the specifications, check the discharge rates. Entry-level batteries will often have discharge rates of only 50 amps, sometimes only 20 or 30 amps. When paired with an inverter, a 50amp discharge rate will only support up to a 500w inverter. anything more than this will overload the battery shutting it down or risking damage to the internal circuitry or wiring. Keep in mind too that when a maximum draw of rate is mentioned, you cannot double or increase this by adding more batteries in parallel. This figure is the total maximum figure.
If you look carefully and check with the manufacturer of the battery even many high-end Lithium batteries do not support running in parallel or may only allow you to connect 2 batteries this way. This can severely limit your maximum capacity to only one battery and many will suggest buying a single 200 or 400 amp battery instead.
This is where it's important to take a look at the claims of capacity that many companies make. An advertising method many will use is to claim that just one of their batteries is equal to nearly two regular 100ah batteries. This is a little misleading as they are referring to usable power, not total capacity. The rating of batteries is done in Ampere Hours, Amp-Hours or AH for short. This is the amount of power that a 1 amp device will use in one hour. So a standard 100ah lead-acid battery will, on average, run a 1 amp light for 100 hours before it's flat. A 100ah Lithium battery will run a 1 amp battery for 100 hours until it too shuts down. So why do these companies advertise that you have 80-100% more capacity? it's because a lead-acid battery should only be drawn down to 40-50% on a regular basis to get the best life out of it. This is around 12.3 volts. Most Lithium batteries will allow you to run them down to either 20%, even sometimes 0%, before their built-in battery management will shut them down. So IF you were to stop using your AGM batteries at 12.3v and go no further, you will get far more out of a Lithium battery. Realistically, most people use their AGM batteries until the system shuts down around 11v though, not stopping at the 40% mark.
Where Lithium batteries far surpass their AGM brethren is longevity and maintaining charges. With good quality Lithium, you should be able to leave them for 3 months or more without topping them up. They are also great at maintaining a high state of charge when using high draw items such as inverters.
While AGM batteries may be capable of 300 duty cycles if maintained well (such as keeping them above 50%) and can fall to under 100 cycles if not looked after, a Lithium battery will usually give you over 2,000 cycles if you're running it all the way down until it shuts off.
If you're planning to do lots of off-grid travelling or free-camping, then Lithium batteries are a great option to maximise the longevity of your system and allow you the most use of the storage as you can get.
Keeping everything above in mind, we recommend that you look at the best quality batteries you can afford, paying attention to discharge rates, IP ratings and installation limitations.
This is why we recommend the range of Zeal and Invicta batteries from BMPRO, as they are well suited to a wide variety of applications and have been designed specifically for use in the RV market.