Batteries R20 and LR20 are designations for the same size of batteries (size - D). The main difference between them lies in the chemical composition (which affects other parameters)
R20 and LR20 have a standard size D. Usually, D-type batteries are zinc-carbon (R) or alkaline (LR). They are often used in various electronic devices such as flashlights, radios, toys, gas water heaters, etc.
R20 or LR20 batteries for a gas water heater?
The question about the difference between R20 and LR20 arose when it was necessary to replace the power source in the gas water heater. The manual specifies - LR20, but the store has R20 in stock. As we have already established - the difference is in the chemical composition, while the size is the same. So I replaced the LR20 1.5V with R20 1.5V (the voltage is the same) because LR20 was not available, and the heater needed to be used. But next time, I need to order LR20 for several reasons (read below).
Why should LR20 batteries be used for a gas water heater?
For gas water heaters, it is recommended to use alkaline LR20 batteries instead of zinc-carbon R20 batteries for several reasons:
Higher capacity: Alkaline LR20 batteries have significantly higher capacity (12,000–18,000 mAh) compared to zinc-carbon R20 (about 8,000 mAh). This means they provide a longer runtime, which is important for the continuous operation of gas water heaters.
Resistance to high load: Gas water heaters can consume a significant amount of energy when activated, especially for electronic igniters. Alkaline LR20 batteries handle such peak loads better due to their chemical properties, while R20 may quickly lose efficiency.
Better performance at low temperatures: Alkaline batteries perform better at low temperatures, which is important if the gas water heater is installed in unheated areas.
Longer shelf life: Alkaline batteries have a longer shelf life and are less prone to self-discharge, allowing them to be used for a longer period without replacement, making them a more reliable option for devices like gas water heaters.
R20 can be used if LR20 is not available. But they will last less time.
By the way, from my own experience, I can say that having a battery charge indicator on the gas water heater is a useful thing. With almost fully discharged batteries - the electronics of the heater behave strangely.
In the photo below, you can see that the Duracell are Alkaline (alkaline), while the worth is Zinc-Carbon (zinc-carbon)
LR20 та R20 (Розмір D, 1.5V)
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