What C-rating are Valen’s front terminal batteries quoted at?

Always check the rate. A 100 Ah battery at C₁₀₀ is not a 100 Ah battery at C₁₀, and comparing two batteries at different rates is the single most common sizing error in this category.

The C-rating states the discharge period over which the capacity was measured. A battery rated 100 Ah at C₁₀ can deliver 10 A for 10 hours. The same battery rated at C₁₀₀ might show 120 Ah or more, because a slower discharge extracts more energy. Conventions by application:

Rate	Typical use
C₁₀	Larger stationary VRLA; also used for charger sizing under AS/NZS 4509.2
C₂₀	Smaller VRLA; general standby
C₁₀₀	Low-load stand-alone power systems

We publish both figures in the specification table above so you can see the effect directly: the ENVIROX-CELPLUS 190 Ah rates 205.2 Ah at C20, and the ENVIROX-CEL 155 Ah rates 167 Ah at C20. Most suppliers publish whichever number suits them. Comparing a nameplate figure against a C20 figure will mis-size a bank by ten per cent or more.

The second variable, equally important and more often omitted, is the end-of-discharge cut-off voltage. The same battery quoted to 1.75 V per cell and to 1.80 V per cell will show different capacities. Two suppliers can quote identical amp-hours at identical C-rates and still not be comparable if the cut-off differs.

For telecom applications there is a hard constraint here. ETSI EN 300 132-2 sets the normal −48 V interface range at −40.5 V to −57.0 V. With 24 lead-acid cells, the −40.5 V floor corresponds to about 1.69 V per cell at the equipment terminals, before distribution voltage drop. This is precisely why telecom reserve tables are quoted to 1.75 V or 1.80 V per cell rather than to a flat battery, and why “how many amp-hours” is the wrong question. The right question is how many minutes at my actual load, to my actual end voltage, at my actual cabinet temperature, at end of life.