Lead or Calcium + What AH Battery do I need for 406

[lakemaligne]

Hi All, I drive a 1996 2Ltr 16 v petrol 406 and need to get a new battery. What type of battery should i fit, considering that my car is quite old and the voltage regulator was set for charging the old type of lead acid battery. I dont know anything about the new calcium batteries and would like to know if i should go for one of these. Is there any advantage over the lead acid type.I would also like to know what the largest rated AH rated battery i should go for on my car to make sure it's cranking voltage does not drop below 10 volts. I ask this because i was told that if the cranking voltage drops below 10 volts ,the ecu fails to initialise properly on start up and the car does not perform correctly.

[Busman]

Greetings.
About 65-70 ah is ideal for your magnificent car. Something in the order of £60 - £70 would buy you a realy good one to cope with the cold weather. The three year guarantee ones are the ones to go for if you plan to keep the car.

Enjoy the car.
Richard.

[lakemaligne]

Hello Richard, thanks for replying .After doing some research on these new calcium batteries,and discovering that they are supposed to hold their charge better in the cold,I decided to go for the 63 AH Bosch Silver Line calcium battery from Halfords which comes with a 5 year gaurantee . Using my Trade card I got it reduced down to £70.00. According to the spec this battery provides 610 cold cranking amps, and certainly spins the engine over fine. I checked with the engine running to see what the voltage was across the terminals and got 12.5v,so i know the charging circuit is ok.

I decided to go for a really good battery,as i have been having tickover and stalling tissues ,which seems to be cured (touch wood) by having the ECU re-initialised and the adaptives reset ,and the Master Tech at my local dealer "thinks" it may have been down to my battery voltage not retaining enough charge to maintain the ECU settings,ane dropping below 9 volts on cranking which is not enough to initialise up the ECU on startup.

By "magnificent car" can i take it that you own the same type of car as me and are as impressed as me with its all round quality ,durability and performance.

Paul.

[Doggy]

After doing some research on these new calcium batteries,and discovering that they are supposed to hold their charge better in the cold,I decided to go for the 63 AH Bosch Silver Line calcium battery from Halfords which comes with a 5 year gaurantee . Using my Trade card I got it reduced down to £70.00. According to the spec this battery provides 610 cold cranking amps, and certainly spins the engine over fine. I checked with the engine running to see what the voltage was across the terminals and got 12.5v,so i know the charging circuit is ok.

I'd be the first to admit I knew nothing about calcium batteries, but after a quick Google, they appear to be essentially lead acid batteries with plates containing calcium to improve life & performance. You would normally expect to see 14 to 14.5V across the battery when the engine's running, (except perhaps immediately after starting due to the very high initial charging current). 12.5V suggests all is not well with your charging circuit.

[Gary406]

12.5 volts with the engine running

are you sure ? it should be 14.5v with the engine running

[lakemaligne]

Sorry Guys ,I made a typo, I meant to put 14.5volts. Thanks for picking up on it though.

Any thoughts on the original battery causing issues with the ECU losing its memory ?

[Doggy]

Maybe something in it - battery voltage will drop dramatically during cranking, in fact I would be surprised if even a new one stayed over 9V when staring a diesel in cold weather.

The absolute number may not be important, it's highly likely your old battery would have dropped further with the combination of bad weather and being on the way out.