CARBON BATTERIES

Carbon batteries are lead-acid batteries enhanced with carbon additives in the negative plate. This modification enables them to withstand daily deep cycling and operate in a partially charged state without sulphation – which is precisely where a conventional lead-acid battery fails.

What are the advantages of carbon compared to AGM?
A AGM A conventional battery suffers when left half-charged for days on end, which is common in a solar installation during winter. Carbon drastically reduces sulphation under these conditions and allows for a much higher number of cycles with deep discharges.
In figures: whilst an AGM battery delivers 500–800 cycles at a 50 % discharge rate, a carbon battery can exceed 1,500 cycles under the same conditions and can withstand deeper discharges without permanent damage.

Carbon or lithium
The lithium LiFePO4 It remains superior in terms of cycle life, weight and usable energy. The carbon battery has its place in three specific situations.
Firstly, cost: it costs considerably less than lithium per kWh installed. The second is temperature: it can be charged at temperatures below 0 °C, something lithium batteries cannot do without a heater. And the third is for replacements in older installations where the inverter and charger are configured for lead-acid batteries and you don’t want to change anything else.

How to charge it
With a lead-acid design, it can handle higher charging currents than a conventional AGM battery, thereby reducing the time needed to fully charge the battery bank. A temperature sensor is recommended to adjust the voltage according to the season.
Any charger o MPPT controller from our catalogue allows you to set up the right profile.

Where it makes sense
Off-grid installations with daily cycling and a tight budget; backup systems that spend long periods operating at partial load; and locations with cold winters where lithium batteries would require the battery bank to be heated.
If you’re unsure whether to choose carbon, AGM, gel or lithium, tell us how you plan to use the system and we’ll tell you which option is really worth it over a ten-year period: free advice.