Selecting a solar lithium battery

[Isetech]

You need to read the warranty forms, the features and all that sales jargon is just that, sales jargon


Warranty Exclusions & Terms and Conditions:

The battery has a 15 year intended design life, however the battery cells should achieve at least 5 years’ service life or deliver at least 3000 charge, discharge cycles as counted by the BMS, which ever event is achieved first.

however a standard 3 year warranty is provided for the BMS

9. If placed in storage then the ambient temperature should be no higher than 25 degrees Celsius.

24. Any damage to the battery caused by peripheral electrical equipment.
The integrated BMS module is designed to last over 15 years, however a standard 3 year warranty is provided for the BMS and all related probes and sensors.
The operating temperature for the battery is designed to be 0 to 55 degrees Celsius, however it is recommended to keep the battery below 25 degrees Celsius to maximise the design life and life cycle of the battery. The cycle life is negatively affected by temperatures above 25 degrees and cannot be guaranteed if the battery is operated in temperatures exceeding 25 degrees Celsius.

[Isetech]

To give you an idea, I downloaded the data for a Sunsynk 5.3 kwh battery, the battery was installed mid November 2022. It indicates that it has cycled 43 times. Lets say 50 cycles per 6 months, that would mean 100 cycles per year.

A quick calculation 6000 cycles/ 100 per year = 60 years.

I have 8 (left) Makita 18 VDC batteries, used on site literally everyday. The batteries are old (cant say the exact date of purchase) years. Had then tested, no faults, SOH 100% 80 % charged at the time of test. Cycles ranging between 450 and 500, which indicated that we are alternating the batteires often.

2 other batteries purchased at around the same time, used with a makita tool which is not star rated and ran flat, both indicated faulty when I attempted to charge them. I stripped then and recovered the cells, still being used for site torches. I should have done the bridge charge, because I beleive it was a BMS cutout issue (you live and learn). I think the manager at Makita was even surprised at how long the batteires have lasted.

I dont understand why the HIlti 36 VDC batteries dont last, I have both 22 VDC and 36 VDC Hilti batteires, the 22 VDC we used everday, the 36 VDC batteries have very few cycles yet they no longer charge, I took them to the hilti store, they indicated they dont ahve a tester for the batteires. Dont try strip a Hilti battery. I am going to rather take it as is, to Hilti and let them dispose of them.