P38A what flattens P38 batteries?

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Sonnycbr said:
Thanks for that Marty, I'll be out soon sitting in the car, in the dark, like a total pervert! I've just watched the vid for the filter that you've developed and I'll be ordering one if necessary. Thank you again for your help.
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I've done the test in the dark and sure enough light went out after 2 minutes. I sat in the car for another 10 minutes and nothing happened. Maybe I do just need a bigger battery. Plenty of time between now and next April when the car will parked up for 2 weeks. Thank you for all the replies, I'll master this car one day!!
 
sassanach said:
ive got one of these on my p38 which at the moment is sat in storage, and im amazed how often the led lights up
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Glad it's working for you - and yes, it is amazing how much RF there is kicking about. The best test we've had of one so far was one of the pre-production units we sent to an owner who was getting a flat battery in 2 days, and even worse, random messages on the dash of ALARM TRIGGERED (it hadn't been) and IGNITION TAMPER (it wasn't) - which he worked out was due to a faulty central heating thermostat constantly sending out stupid signals, rather than a single pulse every 15 mins. We figured it was a good test for the filter - and he was very happy to report back that after 4 days he was able to start the RR first turn of the key and no random messages anymore :) He did replace the thermostat aswell as it was faulty - but it was a good test for us!

DanClarke said:
Total faith in it and @martyuk so have ordered a filter today.
The jog unit has done a great job but 2 remotes on my keyring means a bulging pocket that makes it look like I have a permanent hard-on.
Also, doing a 1..2 with 2 fobs is a faff. So I am grateful for a less fiddly non LR solution.

Ta muchly!
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No problem - order received - it will probably be sent out Tuesday - we are waiting on some more connectors, which should arrive tomorrow, and then also I'm flying back to the UK on Monday and will be home late at night, so will do all the shipping paperwork once I get back and it'll be on the way to you!

Sonnycbr said:
Thanks for that Marty, I'll be out soon sitting in the car, in the dark, like a total pervert! I've just watched the vid for the filter that you've developed and I'll be ordering one if necessary. Thank you again for your help.
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I'm interested to hear the results! Hope it's a simple fix for you!
 
i used to get alarm triggered etc when my rangie was sat outside my house but i never thought anything of it,and as my rangie is lpg'd i do not frequent petrol stations much.when in storage i usually disconnect the battery but since i got this gizmo ive left it on without a maintenance charger and its been fine.i reckon the led is a good way of checking your other vehicles key fobs work as well.all im waiting for now is some decent nasty weather so i can play...........
 
For the moment we've stopped doing them with the status LED as an option, as it wasn't that popular, and we were looking at putting connectors on it to make it a bit easier to install - but haven't yet found any we like the look of and seem small/sturdy enough.

I can fairly regularly leave mine for 3-4 weeks with no issues - the longest mine has sat un-started is about 8 weeks

I'm out in Canada at the moment and there's been a few times here where it's snowed and I've been thinking "If only I had the RR!" Hoping there's some snow at some point when I get home to take mine out to play, as last year every time it snowed, I was away working! Typical!
 
martyuk said:
Battery - I only recommend the MF31-1000 range (Battery Megastore has them branded as Hankook at the moment) or a Yuasa 664SHD (or other type 664). They're the biggest that will fit in the battery tray, and are about 115-120Ah, 1000CCA units.
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I prefer the Platinum ones. Think the code is 642X off the top of my head. Got mine from HTS spares a few years ago.
 
I've been working with Marty on these filters, and its great to see some feedback here from ones out in the wild :)

I'd second the MF31-1000 from battery megastore too - I'm sure there are other options but for the price and availability (quick delivery!) I don't think it can be beat.
 
Had the flat battery syndrome myself some years ago and following advice from here I just disconnected the RF lead and problem solved. I have never bothered to upgrade the receiver as I only use the beast for 3~4 months a year, over the years I have just become used to just locking and unlocking with the key like we did in the olden days. Simples
 
Sloth said:
I've been working with Marty on these filters, and its great to see some feedback here from ones out in the wild :)

I'd second the MF31-1000 from battery megastore too - I'm sure there are other options but for the price and availability (quick delivery!) I don't think it can be beat.
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I just fitted MF31-1000. Standing overnight on my drive and next morning it could not start the engine. I had to use GB40 NOCO Buster Plus. The battery voltage was below 12V.
I am guessing this not just BECM waking up-may be some other source of drainage.
Please list/mention other most likely cause and how to detect/identify the cause.
Thank you.
 
Start by fully recharging the battery with a battery charger.
Suggest you do the 'sit in the car in the dark' first to see if that's a cause or not.
Test, don't guess.
 
lazbaz said:
I just fitted MF31-1000. Standing overnight on my drive and next morning it could not start the engine. I had to use GB40 NOCO Buster Plus. The battery voltage was below 12V.
I am guessing this not just BECM waking up-may be some other source of drainage.
Please list/mention other most likely cause and how to detect/identify the cause.
Thank you.
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Before fitting, the battery should have been fully charged as it may have been sitting on the shelf for some time and been in a low state of charge. With a small 4 amp charger it might need 24 hours or more to reach a full charge.
I have MF31-1000's in both my P38's and similar Hancook batteries in my transit and other cars, never had a problem with them.
 
Or fit duel charger
 

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lazbaz said:
I just fitted MF31-1000. Standing overnight on my drive and next morning it could not start the engine. I had to use GB40 NOCO Buster Plus. The battery voltage was below 12V.
I am guessing this not just BECM waking up-may be some other source of drainage.
Please list/mention other most likely cause and how to detect/identify the cause.
Thank you.
Click to expand...

If the BECM is being constantly woken up by RF interference then it will flatten PDQ. Wireless weather station was doing mine in.
 
Datatek said:
Before fitting, the battery should have been fully charged as it may have been sitting on the shelf for some time and been in a low state of charge. With a small 4 amp charger it might need 24 hours or more to reach a full charge.
I have MF31-1000's in both my P38's and similar Hancook batteries in my transit and other cars, never had a problem with them.
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This morning the voltage across terminals was 11.94V. I started the engine and voltage was 14.3V and after few seconds dropped to 13.96V. After 10 minutes it showed 12.61V. Bonnet (Hood) open all the time.

With the engine running current drain was 14 to 15.07Amps, dropped to 4.19A after few minutes. With engine stopped after 30 minutes current is constant 0.15A Bonnet still open.
The new battery sticker says "Keep above 12.01V (50% discharged) and Warrantee (4 years) VOID 10.6V (100% discharged)"
What deductions can be made from these readings? Is 0.15A drainage still high?
 
Have you fully charged the battery with a battery charger?
11.94v is a deeply discharged battery. 12.6v is fully charged.
Below 12.4v (approx 75% charge) is cause for concern and needs charging.
I'm a little surprised the label says at 12.01v is 50% charged, I'd be expecting 12.10v for 50% and 12.01v to be 25%

Starting and running for a few minutes will at best put a surface charge into the battery but really will achieve little - other than putting an excessive load on the alternator which may not do that any good either.
www.optimabatteries.com/experience/blog/fact-alternators-are-not-designed-to-charge-dead-batteries Ignore the redtop/yellowtop/bluetop bit in the last para.
 
Last edited:
11.94v is bad less than 12,4v is as low as you want on a fully charged battery that has been left a couple of hours
with 11.94 as you start the car the voltage will drop even more and thats when fault start to come up
what was the voltage engine running at 2000rpm with everything turned on lights ect.
 
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