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New battery drained to 4.4v in a week
Posted: 04 Apr 2022, 17:05
by Samanthington
- Brand new (1.5weeks old

) Bosch S4 007 battery from Tayna…chosen after checking out the forums here (thanks Forums!)
- Nothing but the clock is hooked up to it when stationary, except for a split charge relay for the leisure battery (stereo is hooked up to that). Charge on the LB goes up to 14v whilst driving so I’m guessing the alternator is ok and the drain happened after the last (200mile) journey.
- I can’t do the wiki fuse test until I’ve done Tayna’s trick charge method and got the battery back in, so I guess I’m managing my own expectations by asking here…
- for this amount of draw in a week, what could the worst case scenario be!? I’m hoping starter motor, which I might be able to manage myself, just being a worry wort and a wuss!
- there’s an intermittent ignition problem whereby I get nothing when I turn the key; turn it off, turn on again and all good. Could a dodgy ignition switch drain the battery??
Thanks!
Re: New battery drained to 4.4v in a week
Posted: 04 Apr 2022, 17:09
by Samanthington
Earth is super clean, by the way. I haven’t disconnected it, cleaned, rescratched etc, but it looks almost like it just rolled out the dealers!
Re: New battery drained to 4.4v in a week
Posted: 04 Apr 2022, 17:13
by cobblers
It's incredibly unlikely to be the starter motor causing a parasitic power draw.
Is there any kind of alarm or immobiliser fitted to the van, or evidence of one being previously fitted?
For the battery to be so flat so quickly, You have a fairly significant power draw.
Get the battery thoroughly charged up one way or another - ideally leave it on a trickle charge for a few days to rebalance and try and minimize the damage that has already been caused by it being so very heavily discharged.
Doing the fuse test is your next plan of action, there aren't really any "common culprits" on these vans, other than the interior lights being left on or something!
Re: New battery drained to 4.4v in a week
Posted: 04 Apr 2022, 18:42
by Samanthington
Thanks Cobblers, got another battery on charge so I can connect jump leads and get trickle charging the new one. So very gutted
Nothing has been fitted alarm or immobiliser wise, it was pretty much untouched when I bought it, just aged!
Re: New battery drained to 4.4v in a week
Posted: 04 Apr 2022, 18:44
by ajsimmo
Possibly a diode problem in the alternator. Disconnect the wiring to the alternator overnight to see if it still drains.
Sent from my moto g(30) using Tapatalk
Re: New battery drained to 4.4v in a week
Posted: 04 Apr 2022, 18:52
by Samanthington
Thanks ajsimmo, will try that once I can get the battery back in

Re: New battery drained to 4.4v in a week
Posted: 13 Apr 2022, 17:09
by Samanthington
Update….it was a dodgy connection in the cab door light.
Thank heavens nothing too bad!
Thanks for the advice chaps
