trickle charger

Most charger like the one you have will cause the battery to bubble at a rate too high for constant charging. You only need perhaps no more than 10 ma. after the battery is charged to maintain it. There are some smart chargers but they may still overboil the battery. I would actually recommend trying a solar charger. I should install one of those on my vehicles. 5 amps through the battery is certainly going to boil it hard, but not 24 hours a day.

greg

chargers

solar charger.

certainly going to

To add to the above, if you hear/see the battery bubbling (boiling) you are overcharging it.

Get an Optimate II, it also includes a de-sulphate charging mode and constantly checks battery condition when left on charge.

My spare bike didn't get used since the previous MOT, and although the battery was new for that MOT the bike had not been started once in a whole year, when I got the bike out for the last MOT the battery was nearly flat and just starting to sulphate - a couple of days on the Optimate and the bike started first time.

Any good battery maintenance charger should do something similar, the Optimate uses a combination of current limiting and voltage limiting to recover sulphated batteries and continually charge without excessive gassing (electrolyte loss).

On Mon, 06 Nov 2006 10:00:40 -0500, mm Has Frothed:

Remove the battery and store inside.

Why not bring the battery inside? Charge it for an hour every so often.

It's a hell of a price for a tiny power supply. Plenty of real chargers on the market which include an auto maintenance charge - but will also charge a flat battery in a reasonable time. For not much more money.

The Optimate is what the bike shop near me keeps in stock - in other locations there may be more choice.

simple solution put a 24 hout timer on it and let is cycle 1 or 2 hours a day, they run about 5 bucks and work for years

Lead acid battery self-discharges about 1% per day. 1 amp/hr a day would be a serious overcharge.

I wouldn't be surprised if this unit from the 60's didn't use a selenium rectifier...

These operated on the bulk charging principle and relied on the voltage difference between the rectifier output and the battery voltage to determine the current drawn. When the battery is flat the output voltage from the rectifier is high relative to the battery voltage. In this case the maximum current available from the rectifier passes through the battery and the current operated thermal switch then operates to prevent the transformer from burning out. Ideally, As the battery voltage rises with each successive charging burst the difference between the rectifier output voltage and the battery voltage diminishes to the point where they are hopefully nearly equal at around 14V or thereabouts. The thermal switch now remains closed even though some current is being pushed through the battery. Unfortunately, it is never possible for the transformer to regulate at around 14V when the battery is fully charged since because the charging current diminishes the rectifier output voltage tends to increase slightly thus resulting in a voltage differential which produces a fairly high trickle charge. Prolonged trickle operation will damage the battery.

If you want to retain this relic for sentimental reasons you may be able to fit it with an add-on charge regulator kit like this one which was specifically designed for simple low cost units like yours.