# Car battery: How to distinguish between calcium and lead-acid? **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [November 20, 2015, 6:18am UTC](https://boards.straightdope.com/t/car-battery-how-to-distinguish-between-calcium-and-lead-acid/738054 "2015-11-20T06:18:54Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Ken001](https://avatars.discourse-cdn.com/v4/letter/k/43a26b/32.png) [@Ken001](https://boards.straightdope.com/u/Ken001)\ **Post date:** [November 20, 2015, 6:18am UTC](https://boards.straightdope.com/t/car-battery-how-to-distinguish-between-calcium-and-lead-acid/738054/1 "2015-11-20T06:18:54Z")
A hobby of mine is to find discarded 12 volt car batteries and rejuvenate them. I don’t do anything clever: if they show 12v then I shake them to move the acid around and then charge. I have an intelligent charger which tests the battery and goes through a vibration cycle to shake sulphation off the plates. Why bother? In our household we have 5 cars, one tractor, two motorcycles, and two ride-on lawnmowers. The (heavy duty) batteries for my SUV and the tractor cost $300 each. It all adds up very quickly. Plus I like recycling. Calcium batteries require a higher and longer charging rate than lead-acid. However if I mistakenly charge lead-acid at the calcium rate, that boils the battery and it dies. Regrettably a beautiful truck battery sits at the moment in my garage having been erroneously cooked. Not many calcium batteries say “calcium” on the label. How can I check? No-maintenance batteries with sealed tops are usually calcium batteries. However I have two with flush removable plugs which nevertheless claim to be a calcium. ---
**Author:** ![Ken001](https://avatars.discourse-cdn.com/v4/letter/k/43a26b/32.png) [@Ken001](https://boards.straightdope.com/u/Ken001)\ **Post date:** [November 21, 2015, 10:49am UTC](https://boards.straightdope.com/t/car-battery-how-to-distinguish-between-calcium-and-lead-acid/738054/2 "2015-11-21T10:49:20Z")
Umm…nobody? ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [November 21, 2015, 2:17pm UTC](https://boards.straightdope.com/t/car-battery-how-to-distinguish-between-calcium-and-lead-acid/738054/3 "2015-11-21T14:17:47Z")
I’ve never encountered a calcium car battery. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [November 21, 2015, 3:20pm UTC](https://boards.straightdope.com/t/car-battery-how-to-distinguish-between-calcium-and-lead-acid/738054/4 "2015-11-21T15:20:47Z")
I think the OP means Lead-Calcium instead of Lead-Antimony plates. I haven’t been able to find any charging differences between the two. ---
**Author:** ![Cabin\_Fever\_1](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cabin_fever_1/32/2908_2.png) [@Cabin\_Fever\_1](https://boards.straightdope.com/u/Cabin_Fever_1)\ **Post date:** [November 21, 2015, 3:52pm UTC](https://boards.straightdope.com/t/car-battery-how-to-distinguish-between-calcium-and-lead-acid/738054/5 "2015-11-21T15:52:34Z")
Not helpful the the OP’s question, but some ignorance fought in this household. Thank you, and yes, I do have idle time on hand today… > **[How to Charge a Honda Trail 90 Battery](https://itstillruns.com/charge-honda-trail-90-battery-7624551.html)** > > The Honda Trail 90 motorbike was manufactured from 1964 to 1979. It has a lead acid, 6-volt, 5.5-Ah battery and an electrical ignition system. Starting relies on the bike having a fully charged battery. Most original batteries have long since died... > **[Lead–acid battery](https://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery)** > > The lead–acid battery is a type of rechargeable battery first invented in 1859 by French physicist Gaston Planté. It is the first type of rechargeable battery ever created. Compared to modern rechargeable batteries, lead–acid batteries have relatively low energy density. Despite this, their ability to supply high surge currents means that the cells have a relatively large power-to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide th... ---
**Author:** ![Ken001](https://avatars.discourse-cdn.com/v4/letter/k/43a26b/32.png) [@Ken001](https://boards.straightdope.com/u/Ken001)\ **Post date:** [November 22, 2015, 8:30am UTC](https://boards.straightdope.com/t/car-battery-how-to-distinguish-between-calcium-and-lead-acid/738054/6 "2015-11-22T08:30:31Z")
Thanks guys. Just one of those small things I wonder about.