I have two 12v 200Ah Ampere time batteries that were purchased about 4 months apart.
One battery indicated a capacity after testing of 198.42Ah and the other shows 204.12Ah.
Is it safety parallel these batteries?
Is it recommended to parallel these batteries?
What are the consequences and what should I see the capacity to be?
Here is the background:
Last summer (2021) I started setting up a Solar Power system to run an Air Conditioner for my workshop. I have three 360 watt panels into a 60A MPPT charge controller and a 2200 watt Sine wave inverter. I purchased a 12v 200Ah Ampere time battery for the system. After putting things together the system worked well with the battery only dropping about 4 or 5% during the 6 hours the air conditioner was on and it seems that on sunny but mild temperature days the solar was able to run the air conditioner and charge the battery. I decided to add another battery to the system and hook it up in parallel to give ample power on the hot, muggy, overcast days that we get here in Tennessee. I purchased another 12v 200Ah Ampere time battery, about 4 months later, and created equal length 4AWG black and red cables to connect the batteries together and put the positive feed from one battery into the system and the negative feed on the other battery to the system. This seemed to work well for the rest of the summer and into the summer this year (2022). In June I went on vacation for 2 weeks and the temperature remained in the upper 90s for the 2 weeks I was away. When I got back I found that both batteries were depleted (SOC of 0). I charged the batteries enough to jump start the system and left them to charge with the inverter turned off. I am using an AiLi Voltmeter Ammeter Voltage Current Meter, that Will recommended in one of his videos, and it was only indicating about 220Ah when the solar controller dropped to just a few watts on a very sunny day.
I split the batteries up and attached each one to the system and reset the meter to 200Ah. It would still only go up to about 76% on one battery and 80% on the other.
I purchased a 20A charger (with settings for LiFePO4) and charged up each battery with it. I also purchased a MakerHawk Electronic Load Tester. I used the load tester on each fully charged battery. One battery indicated a capacity after one test of 198.42Ah and the other showed 204.12Ah
One battery indicated a capacity after testing of 198.42Ah and the other shows 204.12Ah.
Is it safety parallel these batteries?
Is it recommended to parallel these batteries?
What are the consequences and what should I see the capacity to be?
Here is the background:
Last summer (2021) I started setting up a Solar Power system to run an Air Conditioner for my workshop. I have three 360 watt panels into a 60A MPPT charge controller and a 2200 watt Sine wave inverter. I purchased a 12v 200Ah Ampere time battery for the system. After putting things together the system worked well with the battery only dropping about 4 or 5% during the 6 hours the air conditioner was on and it seems that on sunny but mild temperature days the solar was able to run the air conditioner and charge the battery. I decided to add another battery to the system and hook it up in parallel to give ample power on the hot, muggy, overcast days that we get here in Tennessee. I purchased another 12v 200Ah Ampere time battery, about 4 months later, and created equal length 4AWG black and red cables to connect the batteries together and put the positive feed from one battery into the system and the negative feed on the other battery to the system. This seemed to work well for the rest of the summer and into the summer this year (2022). In June I went on vacation for 2 weeks and the temperature remained in the upper 90s for the 2 weeks I was away. When I got back I found that both batteries were depleted (SOC of 0). I charged the batteries enough to jump start the system and left them to charge with the inverter turned off. I am using an AiLi Voltmeter Ammeter Voltage Current Meter, that Will recommended in one of his videos, and it was only indicating about 220Ah when the solar controller dropped to just a few watts on a very sunny day.
I split the batteries up and attached each one to the system and reset the meter to 200Ah. It would still only go up to about 76% on one battery and 80% on the other.
I purchased a 20A charger (with settings for LiFePO4) and charged up each battery with it. I also purchased a MakerHawk Electronic Load Tester. I used the load tester on each fully charged battery. One battery indicated a capacity after one test of 198.42Ah and the other showed 204.12Ah
