Lead acid batteries sulphate if left uncharged .Is a charge taking over 7 days bad?

A permanent trickle charge does no harm at all, you just need a regulated voltage charging supply with a current limit.

Normally the voltage regulator is set to give 13.8V at the battery when fully charged, and the current limit taken from the makers data - or use 10hr rate (1/10th the amp-hour rating) as a safe value.

That way, the battery will charge within a reasonable time from flat, with the current dropping off to near zero as it reaches full charge.

With this type of circuit, you do not set the 'trickle' current, it adapts to whatever the leakage of the battery is.

I have charged in series at about 0.1% of the rated amp hour capacity, sometimes a week or two of no charging with batteries near the end of their useful life. Typically, they do not deteriorate further for a year or more. I have not tried it with new batteries. Using more than half of the actual amp hour capacity however shortens the life expectancy of even new batteries. Generally the no load voltage should never be less than 90% of the full charge, no load voltage, which is typically less than 13 volts near the end of their useful life. The amp-hour capacity is typically less near the end of the useful life as is the maximum amps that they can supply even briefly. Neil

To maintain battery charge while it was standby, we use trickle charge. That is about 3 to 5% of its AH rate charging current.Trickle charge compensate cell electrical leakage,because the charge current is very low and it shall not over charge the cell.

you're appropriate, charging and utilising batteries in sequence must be completed intently. Your situation is extremely between the guy cellular voltage. Submarines use huge lead-acid cells in sequence. they have a fashion of monitoring each and each man or woman cellular. They use 2 alerts, the guy cellular voltage and particular gravity of the electrolyte to confirm the state of the cellular. i do no longer bear in mind the ideal numbers, yet there substitute right into a particular thank you to cost the battery noted as an equalizing value, which fixes the single low cellular situation. In essence, you value the cells in a classic way till it seems totally charged, and then proceed to overcharge at a low fee. The cells that are already at finished value electrolyze out hydrogen and oxygen whilst the cells that are no longer totally charged proceed to handle greater present day. They proceed till they have utilized a hundred and ten% of what they calculate the completed value might desire to be. it extremely is a adverse element to do because of the fact the H2 and O2 given off is an explosive combination appropriate out of the container. One spark, and bang.. you may desire to keep a watch on the cellular electrolyte point as you're deliberately overcharging some cells and dropping water. In a submarine, they have contraptions fairly there to burn H2 out of the air. you do no longer might desire to disassemble the sequence string to cost the batteries. it may be greater useful if to procure man or woman moist cells than use automobile batteries or a battery with uncovered intercell connectors. you are able to no longer get the guy cellular voltages in a automobile battery. do no longer try this with "maintenance loose" batteries. in the event that they are the gel electrolyte variety, you are able to no longer replace the water the cells lose if overcharged that's why a gel cellular is extremely undesirable (short lived) to apply in a automobile, which overcharge the battery maximum if no longer constantly. while you're very careful, with stable ventilation to dodge the accumulation of H2 and O2, you are able to only value the battery and watch for bubbles interior the electrolyte. Cells that start to bubble are charged. Cells that are no longer effervescent are nonetheless taking over value. it is style of a go-no go try. it extremely is risky! value at a sluggish fee, per threat an amp or much less, and watch the ranges, including distilled water as mandatory to maintain the ranges up.