Polinovel HD Series so called as they are the Heavy Duty model in the Polinovel range
Posted on October 21 2020
Shopping for Lithium batteries can be a mine field. There is a seemingly HUGE difference in price from one brand of lithium 12V 100Ah to another at its extreme this can be as much as a 4 fold price difference from cheapest to most expensive models that on the surface seem to be the same.
As with most products that are complicated and produced on mass there are cheaply made units and there are highly over engineered top of the range products.
Which end of the spectrum is right for you largely depends on what your individual needs are. More information is available in our blog the essential LiFePO4 battery guide. Once you are comfortable about the general benefits of Lithium Iron Phosphate batteries, you may find our beginners guide to current handling an essential resource to help calculate the current handling you need.
With lead acid batteries the basic structure is capable of providing very high current drain rated at hundreds of amperes for short periods of time, but they cant provide that for very long or very efficiently. The lead acid Chemistry cant keep up with the demand for power. This means lead acid batteries quickly loose voltage under high drain applications and cant provide their 20 Hour rated storage capacity if you try to drain that capacity at a high rate of say 100Amps.
Lead acid voltage tends to drop away once you use 50% of the rated capacity so with high power applications you end up with 60 to 70 % only of half of their their labelled storage capacity. eg a 100Ah lead acid could slowly deliver 50Ah of power, yet take that power quickly and the available power drops to 30- 35Ah. this is called the Peukert Effect
Lithium Iron batteries generally need a battery management system to protect the cells and keep them safe, this is a circuit board that monitors the charge discharge, temperature of the battery and voltage to ensure permanent damage does not occur by over filling or completely draining the cells in the battery. This circuit board is built to a different standard in the lowest price batteries and the highest price units, together with other key components like the gauge of the wiring and the method of cell connections inside. It is cheaper to make a thin wired low current battery than a heavy duty high current handling unit. The BMS may limit current drain to a set figure to protect the internal wiring from overheating and damage if it is made too cheaply. For this reason the cheapest batteries on the market typically have the lowest Current handling ability some as low as 40 Amps. The best batteries can handle 200 Amps or more.
Similar to the rating for music speakers there is a PEAK or Pulse current handling (Max Watts in speakers) and a Continuous Current handling. (RMS Watts in Speakers) The cheapest units aim to make the product appear better by claiming max current handling in the published specification as it is the highest figure they can quote and it makes a battery that is recommended to be used at low amps 40 or 50 amps only over a long period of time appear better on paper as its max rating is 100 Amps, yet try to run 100 Amps for more than a few seconds and the BMS will shut the battery down to protect itself. This is a world away from a 100Amps Continuous rated battery that has a MAX or Pulse current rating that is likely to be 2-3 x that of the cheapest units eg about 250- 300Amps for under 3 seconds.
Real quality comes from the recommended continuous discharge rates that is the highest, not a Peak or a pulse discharge rate!
At Quality Source we concentrate on delivering VALUE for money, Highest quality at a modest price. We sell direct as a primary importer directly from the manufacturer of both the batteries and the cells. This enables us to provide excellent quality products at lowest prices.