Andrew Leigh
Member
Hi,
I built this charger years ago and it has served me faithfully ever since. It was a ETI Top Project and I like it, it is fool proof for guys like me as it;
- operates into a short circuit.
- is not damaged by, or will attempt to charge a reverse connected battery.
- can operate into a totally flat battery.
- is regulated for both current and voltage.
- can float a battery for extended periods.
My issue is that when it was designed (think 1979) car batteries were smaller by comparison than today. Ideally it is great for about a 50Ah battery and it puts out 4A. Things have moved on and I would like to double the output but don't have the know how.
I understand enough (I think) to know that the SCR would need upgrading to say a 10A device, as would the heatsink and transformer (mine could be OK as it was over spec to start off with). I already have a 80mm PC fan installed for additional cooling.
If this assists ...... when setting up a totally flat battery is used. Once connected RV1 is used to set the initial charging current. Currently when setting up I am unable to get more than about 4A. One would have thought that without current limiting that the battery would suck more that 4A? Is this a function of RV1 and does the value need to change?
The switch is as a booster for batteries below 4V.
Can the existing circuit drive the 8A load I would like?
Cheers
Andrew
I built this charger years ago and it has served me faithfully ever since. It was a ETI Top Project and I like it, it is fool proof for guys like me as it;
- operates into a short circuit.
- is not damaged by, or will attempt to charge a reverse connected battery.
- can operate into a totally flat battery.
- is regulated for both current and voltage.
- can float a battery for extended periods.
My issue is that when it was designed (think 1979) car batteries were smaller by comparison than today. Ideally it is great for about a 50Ah battery and it puts out 4A. Things have moved on and I would like to double the output but don't have the know how.
I understand enough (I think) to know that the SCR would need upgrading to say a 10A device, as would the heatsink and transformer (mine could be OK as it was over spec to start off with). I already have a 80mm PC fan installed for additional cooling.
If this assists ...... when setting up a totally flat battery is used. Once connected RV1 is used to set the initial charging current. Currently when setting up I am unable to get more than about 4A. One would have thought that without current limiting that the battery would suck more that 4A? Is this a function of RV1 and does the value need to change?
The switch is as a booster for batteries below 4V.
Can the existing circuit drive the 8A load I would like?
Cheers
Andrew
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