The use of batteries in parallel on the pros and cons

A long period of time, whether it is domestic or foreign, but also whether or UPS system, communications system, people are accustomed to using two sets of in parallel with a UPS or a supporting the use of communications equipment. Do not know because the force of habit or because of other reasons, the use of this parallel approach has become the designers and users must follow a principle, but I believe that is totally unnecessary, as long as the users in accordance with the the use of manufacturer maintenance manual for the battery, and only a set of batteries sony vgp-bps15 battery will be enough, not only sufficient, but this group the effect of battery life (such as: battery stability, reliability, balance, in particular battery life, etc.) than with the use of two batteries in parallel when the situation is much better. Especially for VRLA batteries is particularly so. So, why the author advocates a positive (or even do not) it would not be appropriate to use batteries in parallel, which parallel the advantages and disadvantages of using it?

First of all, let’s look at the characteristics of parallel circuit. In parallel circuit, the voltage equivalent to the total voltage of the shunt. In other words, plus two sets of batteries in parallel in each group on the charge voltage and charge voltage equal to the total, that is, U total = U1 = U2. According to I = U / R formula, after the calculation should be able to tell, I1 ≠ I2 (because the two sets of battery internal resistance is certainly not the same, that is, R1 ≠ R2, in the case of U1 = U2 certainly come I1 ≠ I2 of the results). This means that the size of in the same charging voltage, the two sets of parallel use of the battery sony vgp-bps15/b battery pack, which each group received is not the same as the charge current, and resistance of its large charge current small, the internal resistance of the charging of small Current large. In this way, the charge current may be caused by a small group of cells that are often less than the state of charge, with the passage of time, this group of cells may be due to the long-term loss of power and more to increase the sulfate resistance, the resistance the greater the charge current is more small, as the result of such a vicious circle caused by the battery life for this group significantly reduced. But only a set of batteries with such a situation does not exist. This point, it illustrates the use of single battery pack is far better than the results of parallel use. Therefore, the authors suggest that users can use a of equipment to meet the needs of the case, absolutely do not use the use of two batteries in parallel, otherwise it will shorten the battery life, increased use of cost, will reduce the battery performance, should not waste money and manpower to do such things. If the large power equipment, with two sets of parallel battery power still can not meet the equipment sony vgp-bps15/s battery needs, and the use of more than 2 groups, such as the 3 groups, 4 group, or even more groups to use the battery in parallel, it is no more need , two parallel battery use has resulted in many negative, more of the parallel battery use even more complex, more detrimental to the. In this case, we must choose equipment to meet the power needs of large-capacity battery models can be had, if the 12V series of large-capacity battery is not standard, you can choose the battery 2V series, 2V series of batteries, all kinds of large-capacity all of it can be said that how much you need to be able to make much, as far as I know, currently has the largest battery of 2V series can achieve the 6000Ah, our company can provide the largest to 300Ah.

Of course, the designers and users to improve the reliability of standby power supply to consider this point is understandable, for fear the event of AC power failure, the two sets of batteries in a group can not have another power supply when a set of batteries to that, even though dry matter that is also the value of a waste of resources. If it is from this perspective and consider the use of batteries in parallel, and the author in favor of a maximum of only two sets of battery sony vgp-bpl15 battery used in parallel, if more than 2 parallel groups is detrimental to the move. If the non-use of 2 batteries in parallel can not be the case, we should also follow the following principles: First, the use of batteries in parallel must be the same manufacturers, and is the same model, with specifications of the battery; Second, the use of parallel the old and the new state of the must be consistent; The third is the factory of the same batch at the same time; The fourth is to install at the same time.