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Battery not strong enough

shox

Active Member
Hello Everyone,

Im running into a problem with my battery.

It started when i installed my subwoofer (active) 2 months ago. In the beginning i noticed that all the lights of the car were a bit dimming when i was on low rpm (no gas pressed on neutral).

Today i was on the highway and after accelerating hard and then left the engine on neutral, when the rpm gauge reached the bottom my engine switched off.

Yesterday i installed a parrot bluetooth carkit so probably that is draining the battery juice even more.

I should also note down that for the last couple of days my iPhone charger hasn't been able to charge my iPhone (shows its charging but instead of the battery going up, it goes down).

Anyone knows anything about this? Am i gonna need a new battery with bigger capacity, or is it some engine setting??

Thanks in advance!
 
Jun 24, 2007
967
0
durham
if the car starts fine it doesnt sound like the battery is at fault specialy with the readings you have got. and if the alternator was sh4gged that would also effect it
 

shox

Active Member
Some more voltage information:

After using the car for 30 KM, subwoofer unplugged:

- Car on, right after usage: 13.80V
- Car off, right after usage: 12.79V
- Car on, after making the prev. measurements and connecting the sub again: 13.80V

That 13.80V sounds a bit low doesn't it??...
 

joop200789

Active Member
Jul 5, 2009
330
3
Barnsly
sounds like your alternator cant keep up with demand of the sub. three options id say uprated alternator.install capasitors or remove the sub
 

tony_tigger

Guest
wat wattage is the amp for the sub? would check the grounds for the batt and alt...
 

shox

Active Member
wat wattage is the amp for the sub? would check the grounds for the batt and alt...

Its an active subwoofer (Pioneer TS-WX22A) specs are:

Built-in MOSFET 150 W power amplifier
Nominal output power: 60 Watt
Max power: 150 Watt

I think its either the subwoofer draining the bat (and in that case ill get a condenser) OR the ground of the subwoofer needs remaping.. maybe i should use the ground of the rear lights...
 

DEAN0

Old Git
Feb 1, 2006
5,356
347
Preston - UK
Its an active subwoofer (Pioneer TS-WX22A) specs are:

Built-in MOSFET 150 W power amplifier
Nominal output power: 60 Watt
Max power: 150 Watt

I think its either the subwoofer draining the bat (and in that case ill get a condenser) OR the ground of the subwoofer needs remaping.. maybe i should use the ground of the rear lights...

I would just find the nearest earth stud/screw on the body and try it for now.
If there are none near enough - make your own earth point - drill a small hole and use a small nut & bolt.

Where have you picked up the POWER from ?
Is there a remote lead to switch on the sub or is the sub live all the time ?
 

shox

Active Member
I would just find the nearest earth stud/screw on the body and try it for now.
If there are none near enough - make your own earth point - drill a small hole and use a small nut & bolt.

Where have you picked up the POWER from ?
Is there a remote lead to switch on the sub or is the sub live all the time ?

Thats what i did in the beginning, and the ECU complained that the power was intermittent. Thats when i moved it to the seatbelt (which worked for 2 months good). Tho the light dimming still would happen..

For the record, this behavior was also present in my previous car (twingo) with the same subwoofer...
 

tony_tigger

Guest
The traditional advice would be to think about a power capacitor as well as upgrading the wiring of the car.. i mean the battery to earth and batt to alternator. and batt to the sub. make sure the ground for the sub is as good as poss and all should be well!!!
 

shox

Active Member
The traditional advice would be to think about a power capacitor as well as upgrading the wiring of the car.. i mean the battery to earth and batt to alternator. and batt to the sub. make sure the ground for the sub is as good as poss and all should be well!!!

Thanks for the tip. ill look into buying the capacitor today. One question tho, what do you mean with "the sub is as good as poss" ??
 
Feb 26, 2009
5,275
1
Wolverhampton
Thanks for the tip. ill look into buying the capacitor today. One question tho, what do you mean with "the sub is as good as poss" ??

The subwoofer earth is connected as well as possible, IE it's a clean earth...

I would also check the battery earth, all those readings mean nothing if the chassis isn't earthed. Let me guess, you measured across the battery terminals? Try the same reading between the battery positive and a point on the chassis.
 

shox

Active Member
The subwoofer earth is connected as well as possible, IE it's a clean earth...

I would also check the battery earth, all those readings mean nothing if the chassis isn't earthed. Let me guess, you measured across the battery terminals? Try the same reading between the battery positive and a point on the chassis.

Yeah thats how i measured it. good point there. ill check that today.
 
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