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what does this spec sheet tell me?

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2 hours ago, gabriel said:


i attach parts of my battery spec sheet that tell me something important but i don't understand the language, anybody up for a translation please?

i attach the original and the page containing the important data




250ah sonic battery specs.pdf

Let me attempt from a layman's point of view. You have a 48V system and I assume the batteries have 6 cells (the battery is a collection of cells each nominal 2V = 12V). The spec sheet tells you some important information of the performance of the batteries under a specific ambient temperature, in your case 20 degrees. For instance the following specs tell you this:


The AH of the battery changes depending on how long you are discharging the battery at a particular end-voltage. In the highlighted example from your spec-sheet table on this you will see that with an end voltage of 1.85V/cell or 11.1V for the battery the AH of the battery becomes 208Ah over 10hrs. Theoratically you are discharging the battery at about 25A. It just gives you an idea of the storage of the battery at different stages.


In the above table you get a sense of the Watts (stored power) per cell at a particular terminal voltage. If we look at the 10hr period the cell wattage is 41.5W or 249W per battery. You have 4x batteries so expect to draw 996W theoratically from the battery for 10hrs at battery end voltage of 11.1V. In reality you can only really get out 50% of this so the real draw will be less than 498W (allowing for losses). Lets say you have some lights and some appliances of say 300W, you should be able to run them on your battery bank for around close to 10hrs. In reality though the 11.1V is equal to 44.4V for the bank and you do not want to go that low in reality to safe-guard your batteries life so the actual draw to give you 10hrs run time will be lower.


This Cycles graph tells you about how many times you can charge/discharge your batteries at a particular depth of discharge. For instance if you want to takeout 30% (very roughly 3,600W) daily your batteries will give you about 2,750 theoratical cycles. That is a life of around 7yrs at that DoD on paper and ignoring other factors.


These specs on charging tell you that at 20/25 deg your float voltage should be 2.25V/cell or 13.5V/ battery and for your 4x battery system 54V. This is an important factor and you need to perform temp compensation for your inverter charger. 54V is likely the default for your inverter. We are transitioning into winter where I am with temperatures averaging high of about 18deg. That would be a 2deg difference from the 20deg. The spec indicates 1% adjustment/cell or 0.0225V/cell/degree . I would adjust the float charge upwards (lower temp requires a higher voltage charge) by 0.045/cell or 1.08V for the entire battery bank to 55.1V approx.

The cycle service is what is indicated as the Bulk charge voltage on your inverter and the spec at 20/25 deg is 2.35V/cell or 56.4V for the 4x batteries. Again adjusting upwards for our 18deg expected ambient temp, this is 2 degrees drop from battery standard of 20deg:  2 x 1% of 2.35V x 6 cells x 4 batteries = 1.13V + 56.4 = 57.5V approx.

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thanks a lot @Kalito, now THAT makes sense, much more than the technobabble spec-sheet which wasn't even given to me by the installer, i had to source it on the net. worst of all these batteries are sold in different colours with different names [yellow koyosonic etc...] and all from guangzhou, china; when my ship comes in [if] i'll buy a reputable brand with a trustworthy and knowledgeable local outlet whom i can actually speak to.

thanks again for the time you took to assist me here!

God bless


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