Automatic, smart battery charger?
I would like to hear some comments and suggestions. In July 2017, I made some progress on understanding the settings in the MS SS MPPT 15L solar controller. I then modified several settings which ...
Forum Discussion
Why is an adjustable, temperature compensating charger important? We all should know that a battery at 25C is usually charged at 14.4V. We know we can set most chargers to 14.4V But, how often is your battery actually at 25C? Plus how often is 14.4V the correct charging Volts? The answers to both are "Not often".
This is a graph of the bank in my van covering ~260 days. It includes the extremes of Summer and Winter.
The V_Target is the regulated Absorption Voltage as calculated based on the battery temperature. I capped this at 15V.
The plots are of the first minute of the day when the Morningstar SS MPPT 15L wakes up and switches from night to Bulk stage. These are the starting bank temps and charge Volts. Normally the bank temp rises and Volts are reduced during the day. The 15L automatically monitors temps and adjusts Volts throughout the day. Even Float volts are regulated by battery temperature.
Summer is not too bad.
In Winter the constant 14.4V is way too low. With a constant 14.2, 14.4, 14.6, 14.8 setting type of charger, it never is right most of the time. Some chargers have an extra-time override, but then again, it may still not be enough Volts to top-off/finish the charge.
Comments?
HTH;
John
This is a graph of the bank in my van covering ~260 days. It includes the extremes of Summer and Winter.
The V_Target is the regulated Absorption Voltage as calculated based on the battery temperature. I capped this at 15V.
The plots are of the first minute of the day when the Morningstar SS MPPT 15L wakes up and switches from night to Bulk stage. These are the starting bank temps and charge Volts. Normally the bank temp rises and Volts are reduced during the day. The 15L automatically monitors temps and adjusts Volts throughout the day. Even Float volts are regulated by battery temperature.
Summer is not too bad.
In Winter the constant 14.4V is way too low. With a constant 14.2, 14.4, 14.6, 14.8 setting type of charger, it never is right most of the time. Some chargers have an extra-time override, but then again, it may still not be enough Volts to top-off/finish the charge.
Comments?
HTH;
John
