Flat battery

[roachw]

Hi all, I bought my first 7 in Feb this year and noticed it turns over quite slowly even from fully charged battery. The battery kept going flat even with reasonably regular use so I took the car to Bristol batteries where they tested the the whole thing. They diagnosed an 'oxidized' battery so I bought a new, sealed and slightly more powerful battery which ... has gone flat! is this common with 7s? Do we have to leave them on chargetrickle charge all the time?

thanks for any info.

 

Will Roach

[stuart147]

Hi Will

I always leave mine connected to a battery conditioner. The original one that I used was a bog standard Halfords one. I have now however, upgraded to a C-Tec one (nothing fancy though). I find that leaving it un-connected for only a couple of weeks can flatten the battery.

Stuart

 

 

[Jonathan Kay]

What sort of battery is it?

I leave mine on a conditioning charger (not a traditional trickle charger). Others use battery isolating switches.

Jonathan

[Dave J]

the imobiliser can drain a healthy battery in about 10 days. Connect to a trickle of drive it more 

[roachw]

ok thanks guys, I'll try to do both - charge it and drive it :-)

[john milner]

At this time of year a weekly drive should be enough. If a new battery is going flat doing that then something is wrong. In colder weather I take the battery off as the car is kept outside and use a conditioner a few times. If I'm not likely to use it for a couple of days I isolate with a switch as protection against immobiliser drain.

[Johnh]

Might be worth checking your starter motor for a fault (if not already checked)... They can totally kill a fully charged battery in no time when faulty.. If my car is going to be left for more than two weeks I put it on charge using a c tec conditioner ..it works well

[roachw]

hmm that's interesting, since fitting the new battery appx 4 weeks ago, I've been driving it on average twice per week, some weeks 3 - 4 runs, the odd week with nothing so I reckon there's something wrong.

Bristol batteries (BBS) checked the cars system (starter and alternator) and found it all ok so that's why I bought the new battery. The new battery is an Avon 600 amp sealed lead acid, its a BBS own brand item. It replaced a Banner starting Bull 300 amp lead acid (not sealed). The car is a 2015 Roadsport 125 so its very new. Where to go from here? Back to BBS I suppose?

[Jonathan Kay]

The new battery is an Avon 600 amp sealed lead acid, its a BBS own brand item.

Have you got a link to that battery... I don't understand "600 amp"? (And faulty new batteries do occur.)

Going flat with that usage I'd suspect excess drain at rest. But that's unusual on 7s. 

1. Do you have the immobiliser on?
2. Anything unusual fitted or work done recently?
3. What's the battery voltage at rest, during cranking and at 3,000rpm?

Jonathan

 

 

[roachw]

Hi Jonathan, thanks for your reply. I'll find a link for the battery, the immobiliser is left on, nothing unusual fitted or changes made, its all stock. Not sure how to answer Q3, I don't have multi-meter or kit to check it.

I'll dig out info from BBS..

[Jonathan Kay]

Treat yourself to one of these:

It's the second most effective time-saving accessory for 7 owners...

:-)

Jonathan

PS: Where are you?

[john milner]

600 amp probably refers to CCA although important most people refer to the amp hour specification.

BBS may be a typo as a similarly named company sells Avon golf cart batteries - http://www.bblbatteriesonline.co.uk/index.php/search/ead7fb0a7fe6458a78bb034f55d0d295/

[roachw]

I could get one, but I'd have to bone up on how to use it :-)

I couldn't find the info from BBS, I was hoping to find a diagnostic print out along with receipt but no luck. I'll post a pic of the battery box.

I'm in Saltford, between Bristol and Bath.

 

 

 

[roachw]

thanks John, your link is correct. Struggling to post the picture but it says on the box:-

AHR600 (PHCA = 600 amps

SAE = 290 amps)

 

[roachw]

The guy at BBL said the battery is designed to produce max power for first few seconds then a reduced output. Either way, I think I need to check out the Draper meter that Jonathan mentioned to see what's going on.

 

[roachw]

by the way Jonathan, if that muli meter is 2nd most useful item, what's the first?

[SM25T]

Breakdown/recovery membership card ?

[Bristol and Bath AR]

:-)

[Jonathan Kay]

We're using it!

:-)

Jonathan

[roachw]

:-) very good

[roachw]

Hi, things have developed... I've been on a couple of club blats and experienced the flat battery problem again. I always set off with a fully charged battery as I keep it on chargeconditioner, also its a new sealed battery. It appears as though when cold the battery receives charge from the engine and all is fine, when I go on an extended run the battery discharges to the point where it won't turn the engine over (11.4 volts). At the last runbreakdown the AA guy put his meter on the battery and when revving the engine we saw the battery charge level dropping! he diagnosed a wiring fault between the starter motoralternatorbattery. Any suggestions on how I could further diagnose this please? I do have a multi-meter (see earlier posts) but could do with some tips on how where to apply it to gain further info on my problem.

Thanks in advnace ...

 

Will

[Jonathan Kay]

I'd start by measuring the voltage across the battery terminals in three conditions:

• Engine off
• Minimum seen during cranking
• 3,000 rpm.

Does the ignition warning light come on, and does it go off as soon as the engine fires? Do you ever see it on while driving?

That will tell us a lot about what's working and what might not be.

...

Then I'd check the all the wiring and connections to the battery, starter, alternator and the engine earths: visual inspection, wiggle, disconnect, clean and reconnect.

Then the alternator belt condition and tension, have a look at the mounting bolts, and check that the alternator can't be moved by hand.

Jonathan

[roachw]

Thanks Jonathan, I'll make those checks and re-post..

Regards,

Will

[Felixgogo]

As I work away - my Seven is often not used for months at a time. At first I disconnected the battery when away, but now I use a Ctek 5.0 to trickle and condition it. The battery is the original Banner from 2004 and still starts the car on the first press of the starter. No bad for 12 years!

As mentioned earlier - the immobilizer will drain the battery in around 6-7 days.

So you need to either disconnect or charge.

[Jonathan Kay]

Agreed.

The C-TEK and similar chargers are conditioning chargers that measure what's going on and charge accordingly. Traditional cheap trickle chargers (as inherited from fathers' garages etc) don't and I wouldn't recommend their routine use on small Sevenesque batteries

As mentioned earlier - the immobilizer will drain the battery in around 6-7 days.

This seems to be very variable between 7s. I've just tested mine again and it was fine at 14 days on a not very new PVR25 with the immobiliser on. But the 7 (and the Vespa) normally live on conditioning chargers.

Jonathan

PS: Just the one tucked away in there for you, Andrew. :-)