Which one has a higher life cycle: AGM vc GEL batteries?
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I was doing a research for my customer. I ended up reading the Battery Life and Performance Factors on CivicSolar.
Here you mention that Gel batteries are more advantageous in terms of life cycle. I understand that the author has referred to MK/DEKA Battery technical document from where I take the below snapshot.
However, I was reading another article on this link (2nd snapshot added below) which mentions exactly the opposite: The AGM battery life cycle is higher than that of Gel batteries.
The question is; which one is correct?
DEKA GEL battery cycle 1,000 times at a 50% depth of discharge at 77 degrees F, their batteries cycles 500 at 100% DOD.
Comparing cycle life charts of various manufacturers is not easy to do because each manufactures tests their batteries using different testing parameters to obtain the best results for their product. Most manufacturers do not publish their testing procedures.
DEKA results are based on The BCI (Battery Council International) 2 hour Capacity Discharge Test @77 degrees F. This means their batteries were discharged at their 2 hour rate to 1.75 volts per cell (10.5volts for a 12volt battery, a 100% DOD). The battery is then fully charged and is then discharged again. This is repeated until the battery no longer meets 50% of its 2 hour capacity (when it no longer runs for one hour). This is a very demanding capacity/discharge regime.
There are several ways to obtain better results from the test. If you discharge at a 20 hour rate rather than a 2 hour rate, the battery runs more efficiently. If you change the temperature, or the cutoff voltage or many other factors, you can achieve better results.
DELA tests their batteries under a very demanding regime and publishes under what parameters they use for testing. Many other battery manufactures don't state their parameters.
You should push all battery suppliers to share their testing procedures so that you are sure to compare apples to apples and batteries to batteries.
Thank you for the question Jose - we confirmed that the information provided in the article on our web site was correct.