Hello, I bought LiFePo4 2x12V 90Ah batteries for the wheelchair and since I can’t use a standard charger, I bought a Victron Energy | Blue SMART IP22 Charger 24V 12A (Batteries are connected in series). I put the charger in Lion mode, but charging stops after about two hours. The only mode that works for me is high, but I’m worried about that because it’s not designed for these batteries. I’m a complete beginner. Can someone please explain step by step how I can set up this charger for my batteries? Below I present the technical data of the batteries I bought. thank you very much for your help. please excuse my english
If they are series connected you will need a balancer and should do a balance charge with them in parallel first with a 12v charger if you can. The Li-ion setting should be 28.4V if you really want to do a charge as per the datasheet you will need to increase the voltage to 29.2V or 14.6V ea battery. The high setting you are using is 14.7V or 29.4V for a 24V battery. If 29.4V is working then 29.2V might be fine its hard to tell what the problem is because 28.4V should still charge the battery to 100% or close enough. The charger has Bluetooth go into the the advanced battery settings to change the voltage. You should also measure the voltage of the battery to check as well to see if there is a problem with the charge cables.
it seems that you have put 2x12V in series to feed a 24V system.
as Owen said, you need a balancer between the batteries. alternatively you could charge the batteries also individual with two 12V chargers. this would keep the complexity of your system low. just make sure that the two chargers work simultaneously.
Thank you very much, I am already desperate and it seems that I will finally move on a bit. For the time being, I installed this balancer, which is only for lead-acid batteries, and I found out that if I don’t charge the wheelchair, this balancer discharges the batteries on its own. So I would like advice on which balancer to buy for LiFePo4 4 batteries?
Below I am attaching the settings of my Victron charger, specifically the LiFePo4 profile. Please can you help me with the individual items in the settings so I don’t cause a disaster. Thank you
The charge voltage looks fine. I use the powmr balancer in the 48v flavour they also make a 24v. They work very well I can measure up to 10amps being moved around with 100ah batteries. Victron make a 24v balancer that turns on at 28V and uses a resistor to draw down the high battery. This works fine the resistor is only 1amp so if you lower the charge current it does not work as hard.
Thank you very much for your advice, your setup helped me and the charger is charging the batteries correctly. Also the balancer works properly and one problem is solved. However, I had a second problem, and that is that the batteries seem to drain very quickly. Below I attach pictures of how the battery looks fresh after charging and how it looks the next day. If I don’t take into account the capacity indicator and the orientation indicator of the percentage charge, the voltage on the individual cells indicates that the batteries are at about 50%. Am I wrong or is my guess correct?
No its correct 100% full. There is very little capacity above 13.6V and the higher voltage is to let them absorb quicker. Trust the app everything looks ok.