Hi everyone,

lately the car has been giving problems with starting with it cranking over and then finally turning over, I did get a DSC warning light then when the car started it went out. But no battery light is coming on and the alternator is working fine, and so is the starter motor, so I suspect that the battery might not have enough juice to start first time.

So need some advice with regard to buying a new battery if needed, as far as i know my jaguar has an original battery in it which is a 95 Ah Battery Cold Cranking 800 Amps which is for a diesel 2.7.

My problem is there are so many to choose from, but what I don't know is which one holds a decent charge for a start up as I suspect that is the issue, as now you have these start/stop batteries.

So need some advice as to what battery to go for I have seen the following:

G3 Varta Blue Dynamic Car Battery 12V 95Ah (595402080) (017 019)
G14 Varta Start-Stop Plus AGM Car Battery 12V 95Ah (595901085)

any help or advice is very much appreciated.

 

I fitted a Varta Silver Dynamic H3, 100Ah 830CCA, which fits the battery tray fine.

I got it from Battery Megastore (they're in Tewkesbury) for around £80 (last Nov). Oh £89 now.

 

Make sure you have a vented battery with the 1/4 in rubber vent tube extending from the battery through the boot floor to the underside.

 

The original equipment as specified for your vehicle was a wet cell design. AGM is one of the substitutions, and you will find them an upgrade to flooded designs.

AGM batteries are lead-acid batteries that hold or suspend the electrolyte in a high-absorption micro-glass mat that acts as the separator material between the positive and negative plates. AGM batteries do not emit hydrogen and oxygen externally like flooded lead-acid batteries. Instead, AGMs have an oxygen-recombination chemistry wherein oxygen recombines between the negative and positive plates during discharge and recharge. An AGM battery has a much lower internal resistance than flooded lead-acid batteries therefore allowing a higher recharge acceptance. What’s more, AGM batteries are Valve Regulated Lead Acid (sealed) batteries that do not have an open vent system like flooded lead acid. With their unique internal assembly and physical design, an AGM battery’s vibration resistance is normally high (5 to 10 times that of flooded batteries.)

Similar to flooded batteries, there are differences between AGM batteries. Some AGMs have the common characteristics mentioned previously. These as known as Single Stage AGMs. Other AGM batteries have these same characteristics plus have other attributes. These batteries, referred to as Dual Stage Performance AGMs, feature:

• Higher recharge acceptance characteristics than flooded or Single Stage AGMs. Dual Stage performance AGMs have an even lower internal resistance than other AGMs due to their improved lead purity levels - approximately 99.9 percent pure.
• An improved power capability at extremely low temperatures than their flooded or Single Stage AGM batteries counterparts.
• Three to four times the amount of deep cycles than Single Stage AGMs due to the active material density levels. Unless the AGM battery produces approximately 400 deep cycles to 80 percent depth of discharge (DoD) and/or 600 to 700 cycles at 50 percent DoD, it is not a true deep cycle.

In addition, Dual Stage Performance AGMs can produce both high levels of CCA (Cold Cranking Amps) and vehicle starts due to the number of plates per cell, and hundreds of deep cycles at the same time.

The greatest risk of damage to AGM's is over-charging and over-voltage.

The latest Gel Cell designs are sensitive to charge rates, and require some considerations to alternator regulators, and would not be on my list of candidates.

What do I use in my XJ8? Flooded, non-AGM design.

 

FWIW, I use a Super Start Platinum, AGM battery, part # 49PLT, 850 CCA that I got from O'Reillys 3 years ago and has and continues to perform flawlessly.

 

Sourced it from Advance Auto. It has the vent also. Reading above it indicates there should not be a vent in a true glass mat battery.
I have gone to AGM batteries in all our vehicles.

 

The reason I have not chosen AGM for my vehicle, is AGM batteries are sensitive to overcharging. A charge to 2.40V/cell (and higher) is fine; however, the float charge should be reduced to between 2.25 and 2.30V/cell. (summer temperatures may require even lower voltages) Automotive charging systems for flooded lead acid often have a fixed float voltage setting of 14.40V (2.40V/cell); a direct replacement with a sealed unit could overcharge the battery on a long drive. AGM and other sealed batteries do not like heat and should be installed away from the engine compartment. Manufacturers recommend halting charge if the battery core reaches 49°C (120°F).

Locating the battery in the boot is AGM friendly, however, voltage regulator in the alternator can lead to over-voltage and over-charge. Also, there is no method of sensing battery temp. AGM's are a great idea, but older technology in charging systems were never designed to deal with this. Long battery cable runs to the boot, can work in your favor though, as voltage drop due to the length can decrease voltage at the terminal.

 

Just as a caveat, ConsumerReports did some testing of AGM's and did find some performance unacceptable in automotive usage. Failure rates with some designs were high, (failure in just weeks or a few months) and when it comes to any technology, it can be daunting in your selection.

 

hi all,
thanks for the info, but still not an easy choice for one to make, so might decide to go for this battery:-
Type 019 Varta Silver Dynamic Car Battery 12V 100Ah CCA 830(Short Code: H3) (Varta DIN: 600 131 080 or 600 402 083).
Just need some views about the higher rating will it effect the car etc as original battery is 95Ah and CCA 800, thoughts appreciated.
Thank you.

 

The higher rating will pose no issue.

 

Thank you.
Probably will purchase this week. All of you who shared your thoughts. Thank you very much for the advice.