Hello to everyone!

I'm searching for suggestions about making a linear power supply for a lead-calcium battery with 3 modes (slow, normal and fast).
In the schematic I'm using a LM338K to supply +12V to the control circuit and the battery, Sorry for the messy schematic.

 

What's the purpose of this supply?

If it's for charging the battery, that's not the correct way to do it.

 

lead calcium ???? that's a new one on me ....

"The difference in lead calcium batteries and lead acid batteries is the electrode inside the battery actually has not only lead but it also has a calcium material used to manufacture that electrode. the benefit of that is that it works better in cold temperatures and also it reduces the overcharging gassing and water usage which are eliminated in our batteries because they are sealed. So no gas is escaping, no water is used through evaporation and due to the fact that we add an external heater to the batteries there's no need for any type of cold weather specific battery. So due to these facts our products have the capability of using either let acid or lead calcium and still maintain the specifications..."

 

Most AGM batteries are Lead-Calcium ...

https://batteryuniversity.com/learn/article/lead_based_batteries

"...
The grid structure of the lead acid battery is made from a lead alloy. Pure lead is too soft and would not support itself, so small quantities of other metals are added to get the mechanical strength and improve electrical properties. The most common additives are antimony, calcium, tin and selenium. These batteries are often known as “lead-antimony” and “lead-calcium".

Adding antimony and tin improves deep cycling but this increases water consumption and escalates the need to equalize. Calcium reduces self-discharge, but the positive lead-calcium plate has the side effect of growing due to grid oxidation when being over-charged. Modern lead acid batteries also make use of doping agents such as selenium, cadmium, tin and arsenic to lower the antimony and calcium content.
..."

 

Hello to everyone!

I'm searching for suggestions about making a linear power supply for a lead-calcium battery with 3 modes (slow, normal and fast).
In the schematic I'm using a LM338K to supply +12V to the control circuit and the battery, Sorry for the messy schematic.

Where does the battery connect in your schematic ?