Battery Recommendations

[TANGO7]

I have just replaced the defunct battery on my 1600 Crossflow with the recommended Banner 53034 (30Ah  300A). The battery is fully charged but when starting the car the engine turns over very lethargically, but does usually fire up. Is the battery not up to the job and if so any recommendations for a more suitable one? Any other thoughts on the problem? 

[Jonathan Kay]

For current recommendations see "What's the best battery these days".

Unless you're considering a lithium battery.

(I try to keep both of those threads up to date with costs, masses, oomph, experiences and suppliers. All contributions appreciated.)

Jonathan

 

[Jonathan Kay]

The battery is fully charged but when starting the car the engine turns over very lethargically, but does usually fire up.

I suggest:

1. Checking the fluid level in the cells.
2. Measuring the voltage across the battery at rest, minimum during cranking, and at 3000 rpm, and letting us know all three values.
3. Inspecting all of the relevant wiring and connections, including the earths. Look, wiggle, disconnect, clean and reconnect.

Jonathan

PS: How do you know that the old battery was defunct?

[K7 VCT]

Had 3 caterhams in total of 12 years of ownership, yet never had to replace a banner battery.

As long as you look after them they look after you.

Suspect you may have a problem that's not the battery.

[TANGO7]

Jonathan

Thanks for your comments.

Fluid levels are all ok. I have checked/cleaned all earths and connections. What values would you expect from the 3 readings you suggest taking?

The old battery would not hold an adequate charge.

[TANGO7]

K7 VCT​

Thanks for your reply. Any suggestions as to the potential problem other than connection problems?

[John Vine]

Any suggestions as to the potential problem other than connection problems?

Is your starter up to scratch?

JV

[Bricol]

They tend to fail after year 4 . .. so three Caterhams, 12 years . . . :)   That's even on a conditioner. 

I've been using Yuasa equivalent for the last two batteries.  Probably 2 or three Banners and one Yuasa in the last 19yrs on one Caterham.  They just don't like inactivity.  In the same time I've had one battery on the Lancia which was used daily until a few years ago.

[Bricol]

Easy way to see if the battery is up to it - connect another to it with jump leads.

Might be simply be a slow, worn, dirty starter motor

[K7 VCT]

A friend has just swopped his k series starter to a wasp replacement unit after replacing a suspect banner battery.

He fitted the original battery after the new wasp starter was fitted, he is keeping the new battery as a spare now.

As the starter was the primary problem

 

[TANGO7]

Jonathan

Readings as follows :-

At Rest 12.8 v

Min on Cranking 10.8v

At 3000 rpm 14.6v

These readings would seem ok to me (except may have expected a slightly higher "At Rest" value) and suggest the Battery is ok (being new it should be !)

Suspect I may have to look at starter motor or solenoid. (Concuring with #7,9 10 above).

[Jonathan Kay]

It's good to see > 10.5 V minimum during cranking. That's both to give enough oomph to the starter and to make sure that no electronics such as the ECU are complaining. 

14.6 V also looks OK for the built-in charger.

... except may have expected a slightly higher "At Rest" value

Agreed.

... being new it should be !

There are at least two reports in the archives of new batteries being duff! 

I have checked/cleaned all earths and connections.

That's everything at the starter and solenoid and the engine earth, not just the connections at the battery poles?

... but when starting the car the engine turns over very lethargically, but does usually fire up.

Hmmm... with a duff battery cranking usually gets worse the longer you try.

I'd now try with that jump from another vehicle or battery and repeating the first two voltage measurements as well as seeing how it cranks and fires.

Jonathan

[ECR]

I had what appeared to be a failing battery recently. The engine would turn over but only slowly, eventually it might fire up but not always. It turned out that one of the two wires connecting the brushes in the starter motor was semi fractured restricting the flow of power.

It might be worth removing the starter and checking internals (or have it checked by a specialist)

[garybee]

It's a good idea to check the voltage at the post of the starter whilst cranking.  Not sure from what you've written if you have already done this.  Checking the voltage at the battery leaves potential for poor connection between starter and battery. 

The connection can be poor even when it appears good and is tight.  I've had leads corrode and crack under the insulation.  In that case the connection at the terminal would appear sound and the battery voltage would remain good whilst cranking.  if you measured the voltage at the post however it would immediately show where the problem lies.

[TANGO7]

Many thanks for all your comments and suggestions.

I have cleaned, checked and re tightened ALL connections.

Connected a second (fully Charged) battery to the new in situ battery and checked measurements with the 2 batteries :-

At Rest :- 13.1

Cranking :- 10.5

As #14 I have also checked (single in situ battery) from battery terminal to starter post, which gives a reading of 10.3 on cranking. 

So much the same readings with 2 batteries and the above reading to starter post of 10.3 (as opposed to 10.5 across the battery) would suggest connection from battery to starter motor is OK.

I am coming to the conclusion that there may be a problem with the starter motor perhaps sticking or drawing too much current.

BTW Jonathan what's an ECU ??? 

 

 

 

[Jonathan Kay]

... what's an ECU ??? 

Is this a Crossflow in-joke? :-)

What ignition and fuel control system do you have?

(But this isn't going to help with your starting.)

Jonathan

[Jonathan Kay]

And as lethargic as ever with the second battery helping?

I am coming to the conclusion that there may be a problem with the starter motor perhaps sticking or drawing too much current.

Yes, I'd get a local electrician to look at the starter and solenoid.

Jonathan

[TANGO7]

Same lethargy with the second battery fitted.

I presumed the solenoid is OK as there is current getting to the starter motor and the drop on cranking is similar when tested at the starter motor terminal to when tested across the battery. 

Next step is to remove starter motor and get it checked out.

(Ignition/fuel systems are standard factory i.e. Lucas and Webers).