How long should it take to charge 24v 250ah flooded tubular battery using mppt100/50. Consider 1400w at the mppt input from pv. Charging from cutoff voltage. Tested results would be nice.
asked
Quiz. Time needed to full charge
20/50/80 DoD?
Dear Sir ,
From personal experience ,without being an expert.
1400W on label solar array will provide 1000W maybe at the lowest 800W.
so if you say at 1000W@ 24V you get 40Amps ( approx. ) ( Math P = I*V)
so every hours you gain 40Ah ( 40 A per hour )
so if you are at 50% capacity (125ah consumed from the 250Ah) so you will need 3.125 Hours of Charging at 40A continually to get to full capacity / and after that a few more minutes to equalise and switch to float.
At least from my experience more or less that is how it goes.
If someone has a more official way to calculate this be my guest I am no expert.
Thank you in advance
The Harvester.
Would the acid battery accept the 40a through. I think from sheet max charge is 10%.
40A would be a bit to much.
Recommended for lead batteries is to charge them with 10-15% of it's capacity. So in your case 25-37A.
We have now 40a from internal charger when grid is on + 40a or so from pv. What happens when you have 80a going in using default settings easysolar 24/1600
your EasySolar wont be able to deliver 80A. according to the datasheet it is able to supply ~1400W continuous load. that means, your bulk charging current might go up to 50A max (1400W/27.6V).
but to prolong your SOH of the batteries, I would also recommend to max charge with about 30 to 40A.
edit: if I get this right, your setup consists of a BlueSolar charger 100/50 and the EasySolar? Charging the batteries with much more than the suggested current will cause them to 'die' much much early in time. Better stick to the reference in the manual or risk broken batteries....
My understanding for the 1400w limitation is for the power coming from pv. The internal charger is separate unit which uses AC power so you can still reach the 80+a.
The unit is the all in one. Does it provide charging current limitation based on battery type in this case.
what @Helios-Harvester said, should roughly work out, depending on the sun... of course.
my guess with the help of a little math and conversion losses (+10/15%) @ 20% DoD were about 5-6h charging time.
