I have recently purchased a Halfords 12V calcium battery second hand off facebook. I was told it was about 6 month old ( it does look new ).

The problem is it will not charge using my trickle charger' that works fine for all my other batteries.

Do these new calcium type need some special charger?

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    \$\begingroup\$ How about you locating a data sheet for it to see what charge levels it needs? \$\endgroup\$ – Andy aka Nov 23 '16 at 15:51
  • \$\begingroup\$ How much voltage can you measure across it? If you have a "too" smart charger, there are many ways to cheat to get it going and potentially save your battery. It might be dead though. \$\endgroup\$ – winny Nov 23 '16 at 15:54
  • \$\begingroup\$ Calcium batteries require a slightly higher voltage charger, I believe it's more like 15V. \$\endgroup\$ – pjc50 Nov 23 '16 at 16:27

The problem is it will not charge using my trickle charger

The typical lead acid charging voltage is between 2.15 volts per cell (12.9 volts for a 6 cell battery) and 2.35 volts per cell (14.1 volts for a 6 cell battery).

The ideal charging voltage for a calcium battery is 14.8V for the recombination process to properly occur.

The above indicates that your trickle charge will not deliver enough charge to completely recharge you battery.

If it does charge, it might be worth considering whether your alternator is suitable for a calcium batttery, (I think most bring the voltage to around 13.6V).

Be very careful around the battery, the voltage is small but the current can be massive, you do not want a silver necklace to fall between the terminals!!

  • \$\begingroup\$ @Johnboy you're welcome. However, I'd advise extreme caution when working around car batteries, (especially as I don't know your level of electrical knowledge). Check out this : thegreynomads.activeboard.com/t55542005/… \$\endgroup\$ – SeanJ Nov 28 '16 at 9:44
  • \$\begingroup\$ Hi Sean thanks for the advice, my first year into my apprenticeship as a mechanic back in the 70's taught me to respect the 12v battery when I almost melted a 13mm spanner removing a starter motor ( battery still connected ) ... :) \$\endgroup\$ – Johnboy Dec 4 '16 at 6:07

The battery is most likely scrap. Calcium batteries are lead batteries that tiny amounts of calcium added to the plate to improve performance -- the problem is they can be very very difficult sometimes impossible to recharge if battery has become deeply discharge even with a special charger. Most smart chargers simply will refuse start the charging process . There are special smart chargers that sometimes work if left on for weeks or sometimes an ordinary high output old style charger if left on a high setting will eventually start the charging process but this way needs care.



If you connect your flat battery to a good battery (with jumper leads) then connect smart charger to the discharged battery it will start the charging process. Leave batteries connected for about 10-15 minutes then disconnect charged battery & the charger should continue to charge the discharge battery.

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    \$\begingroup\$ Welcome to EE.SE. Did you notice that the question is about a calcium battery? Your answer might be relevant to a question on standard lead-acid batteries but are you sure it is correct in this case? \$\endgroup\$ – Transistor Sep 1 '18 at 11:40

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