Indeed. The guy at MK confirmed the charger I currently have is ideal for the job, initially charging between 4 and 6A and floating at around 13.5. I am charging it again now and will monitor the charge voltage this time.
Incidentally it says on the Draper instructions that the BCI charger draws 110W and that's exactly what the power meter socket said it was drawing. ;-)
Understood and I did confirm the maximum discharge voltage (minimum voltage) with MK to be 10.5V (on load).
Yes, and why I was happy my charger was at the low end of the permitted charging scale. I think there are realistic minimums for intelligent (they would be maximums for float chargers of course) chargers though. Having enough charge 'lift' to be able to measure the battery's reaction to them accurately etc.
Indeed not, however, at least with non sealed batteries you can top them up. I remember my electric car (with 8 x 200Ah 6V mono blocks) needing regular checks and the occasional drop of distilled water.
As I understand it these batteries / chargers have 3 key stages, bulk, charge and float.
The fist stage is where the bulk of the charge is applied, often current limited by the abilities of or settings on the charger. It doesn't matter what the terminal voltage would be for most of this because it's in a current limiting state anyway.
However, once the battery has reached it's terminal voltage (dependant on several criteria like age, temperature, charge current etc)it requires the 'absorbsion' phase where the voltage stays the same and the current then drops back to it's minimum (that again dependant on certain criteria).
From then on the charger would drop back to a float or maintenance phase where it will maintain a lower voltage (as you have also said) offsetting any self discharge etc.
The fancier chargers can prepend the bulk phase with a de-sulphation stage and others can apply tests and timers along the way to ensure the battery isn't faulty and or if it is to reduce the charge rate or repeat the entire cycle etc.
That's my best understanding of it anyway. ;-)
Cheers, T i m