There are many batteries on the market that cost half the price of top brand batteries. I tested three cheap batteries and tried to figure out if they could be used.
Lead-acid batteries 12V 7Ah are most often used in UPS (UPS) and uninterruptible power supply units (UPS) for alarm systems, access control and video surveillance.
I bought three batteries in Ozone: Alpha Battery FB7.2-12, I-Battery ABP7-12L, Optimus OP 1207. They cost approximately the same - about 680 rubles each, while the price for branded batteries of the same size and capacity starts from 1,500 rubles.
On the batteries themselves, the same parameters are written, with the exception of the maximum charge current:
Alpha Battery FB7.2-12 - 2.16 A;
I-Battery ABP7-12L - 1.2 A;
Optimus OP 1207 - 2.1 A.
Alpha and Optimus have narrow F1 terminals, 4.75 mm. I-Battery has wide F2, 6.35mm and even has protective caps.
According to specifications, the Alpha Battery FB7.2-12 should have a capacity of 7.2 Ah with a 20-hour discharge up to 10.5 V (1.75 V / cell), provide long-term discharge current up to 21.6A and short-term up to 135 A for 5 with. The manufacturer indicates that the battery is intended both to provide backup power to the security and safety system, and to work in a UPS.
V specifications of the I-Battery ABP7-12L, it is indicated that it must have a capacity of 7 Ah with a 20-hour discharge up to 10.5 V, provide a long-term discharge current up to 21 A. It is also designed for both security and safety systems and UPS.
V specifications the Optimus OP 1207 battery only indicates that it is intended for security and access control systems, emergency lighting systems, electronic cash registers and other equipment and is not intended to work in UPS. Not a word about working and limiting currents, only a capacity of 7 Ah is indicated with a 20-hour discharge.
I had two new Alpha Batteries FB7.2-12 purchased at a couple of months' intervals. The second has a white "Dahua Storage Battery" sticker. It turned out that these batteries are very different from each other, so both are present in the test.
I charged the batteries with a current of 1.2 A to 14.8 V (first, they charge with full current, and the voltage rises, then the voltage reaches 14.8 V, and the current begins to decrease).
Testing was carried out using a modified EBD-USB + device connected to a computer.
Heavy load tests were carried out with a 500 W inverter and a 300 W incandescent lamp, as well as an Ippon 600 VA UPS and a 200 W incandescent lamp.
Internal resistance was measured with fully charged batteries using the YR1035 + instrument.
In total, five tests were carried out:
- discharge with a current of 0.35 A to 10.5 V - a basic test showing the real capacity of the batteries;
- repeated discharge with a current of 0.35 A to 10.5 V - it turned out that in the second cycle the batteries give a slightly higher capacity;
- discharge with a current of 2.8-3 A to 10.2 V - a test showing how long the battery will last in a three-amp power supply unit (the current changed due to the fact that EBD-USB has a power limit of 35 W);
- discharge by an inverter with a 230 V 300 W lamp (~ 30 A) until the inverter is turned off (9.8 V);
- discharge by an uninterruptible power supply with a 230 V 200 W (~ 20A) lamp before the UPS is turned off.
I got the following results:
As you can see from the table, the measured capacity of the batteries with a "20-hour discharge" turned out to be significantly less than the declared one: 4.5-5.9 Ah, and not seven at all. When discharging with a current of 3A, the given capacity decreased to 3.4-3.8 Ah. When discharging a 200 W lamp through an inverter, the batteries were able to give only 1-1.3 Ah. The 200-watt UPS lamp worked for only one and a half to two minutes. Two, similar in appearance, Alpha Battery with different dates of production (they are encrypted in codes, but how to decipher them is unknown) turned out to be completely different.
For example, I will give a table of discharge currents of the WBR GPL 1272 brand battery.
In the bit tables, the opposite is indicated - in the cells the currents "adjusted" for a certain operating time. It can be seen from the table that such a battery gives 7.5 Ah when discharging with a current of 0.377 A to 10.5 V, approximately 4.5 Ah when discharging with a current of 3 A to 10.2 V and approximately 2.7 Ah when discharging with a current of 32.6 A to 9.6 V. I hope that all these parameters are true and the same UPS with a load of 200 W will work twice as long from a branded battery.
Pay attention to the weight of the tested batteries - it is about 1.7 kg. Branded batteries with the same declared capacity weigh 2.4 kg.
It turns out that 30% of lead was "under-supplied" in cheap batteries.
Another aspect is service life. For branded batteries, the service life is 5-12 years, for cheap ones, 3-5 years. It is difficult to say how much the batteries will actually work - it depends on the operating conditions and on whether the manufacturer lied a lot.
Does my research mean you can't buy cheap lead-acid batteries? Not at all! They can be bought and used, but you need to understand that the "7Ah" of a cheap battery is not the same as the "7Ah" of a branded one. These batteries can be used in a power supply unit, and even in a UPS it is possible, provided that the electricity is turned off very rarely. Yes, such a battery will probably fail earlier than a branded one, but it costs half, or even three times cheaper.
Of the three batteries tested, I-Battery ABP7-12L turned out to be the best. I have already bought a second one of the same and its parameters were close to the first.
© 2021, Alexey Nadezhin
For ten years I have been writing every day about technology, discounts, places of interest and events. Read my blog on the site ammo1.ru, v LJ, Zen, Mirtesen, Telegram.
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