Please Assist me with the correct charging settings

[PaulB_]

Hi all.

I decided to replace my 3000w 24v inverter's batteries, as they were toast.

I settled on a pair of 12v Digimark 200ah Gel solar batteries - with the eventual aim to buy a few more within the coming months.

So far - it's working beautifully - but I am starting to see small signs (perhaps I'm paranoid) of the batteries capacity already decreasing only a few months into the use of the new batteries - and I have never run them even 50 percent.

The closest I got was 24.3v - this was during a 4 hour stage 6 episode. I was advised in order to protect the life of the batteries was to switch the inverter off as soon as the voltage got to 24v, as this would roughly mean 50% of capacity was used, and it's best not to run these deep cycle Gel batteries below 50%.

This morning - I saw with the mains still on the batteries were fully charged to 27.6v. A few minutes after Eskom cut the power the batteries were aleady at 25v - a few weeks ago, it spent at least half an hour going from 25.3v down.

Perhaps the batteries are fine, and I am just running an intensive load.


A 10 year old Desktop, a laptop, 20" PC screen 2 DStv decoders, and a 55" TV. Plus a gate motor, two keypads, a fan and a magnetic gate lock, and various routers, and access points, and of course our ONT. My bedroom light is also on the inverter. (Most of these things are off or in standby mode at the time of typing.

At the time of messaging we currently 38 minutes into load shedding, and the inverter is reading 24.9v with a 11% load.

A few questions.

1. I don't have a balancer installed, as I was advised by someone who's well acquainted with electronics, and engineering that it's not needed for lead acid batteries, and is only needed for Lithium Iron Batteries. However if it is needed to ensure the life of the battery remains healthy, I won't hesitate to go out and buy one if I can find one at an affordable price.

2.I want to ensure the best life of my batteries for as long as possible, so need to please get advice with regards to what the best charging settings are. I have attached a photo of the manual which details settings. If someone would please be able to let me know what settings would work best, it would be much appreciated.

Thanks so much.

 

[B-1]

Its pretty easy to check if a balancer is needed. Test the voltage of all the batteries with a multimeter and see if they have gone out of balance. They are definitely not immune to voltage drift and after a few months you should see a difference already.

 

[Tomtomtom]

You are probably seeing them settle into their "middle age" which with luck will last a couple years. Bad news with lead acid is you need to discharge them less than 25% or so if you want a hope of them lasting thousands of cycles (i.e. a few years at stage 3+). Doubling capacity more than doubles lifespan, so consider doing that now.

For continuous stage 6+ there's no solution besides lithium and fast charging.

 

[Djofs]

I have the same Digimark batteries running in series for 48V (4 x 12V) system. Have been running for 3 years now purely as load shedding back-up. So far no degradation, but I never go lower than 75% and no heavy loads (only lights, TV's, Decoder's) Settings should be maximum lower cut off 45V (11.25V). Float - 54V (13.5V) and very important maximum CHARGE voltage should never exceed 56V (14V) or you will damage the batteries. Gel batteries must be charged slower than lead acid. Should last between 5 and 7 years, if you are lucky and don't abuse them. Good luck.

 

[Pineapple Smurf]

I have the same Digimark batteries running in series for 48V (4 x 12V) system. Have been running for 3 years now purely as load shedding back-up. So far no degradation, but I never go lower than 75% and no heavy loads (only lights, TV's, Decoder's) Settings should be maximum lower cut off 45V (11.25V). Float - 54V (13.5V) and very important maximum CHARGE voltage should never exceed 56V (14V) or you will damage the batteries. Gel batteries must be charged slower than lead acid. Should last between 5 and 7 years, if you are lucky and don't abuse them. Good luck.

Lithium 48v Battery Balancer / Equaliser (suitable for all battery types) - 24V, 36V or 48V (2-4x 12V Batteries) - GeeWiz

Lithium 48v Battery Balancer / Equaliser (suitable for all battery types) - 24V, 36V or 48V (2-4x 12V Batteries) for sale online at the Best Prices! Door to Door and Overnight Delivery

www.geewiz.co.za

Thank me in years to come when all 4 batteries are still equalised

 

[Djofs]

Thanks. I actually have the same balancer installed right from the start. You are correct, I think its a must have on any system.