The Prelude charging system and battery questions!

Post by **RattyMcClelland** » Wed Mar 12, 2014 6:23 pm

I need someone to do a test please.

Im not sure how my charging system is coping.

Battery voltage is around 12-12.4 with engine off.

When i start the car battery voltage is around 12.4-12.5.

When i rev the car to around 3k and hold it a little it goes to around 13.8v.

This is all on a stone cold start.
Trid with the lights on and seems about the same.

Whats the verdict? Battery is relocated to the boot and everything seems wired up correctly.

How long will a lude with on battery power alone?

batkosio · Post by **batkosio** » Wed Mar 12, 2014 6:39 pm

Approximately 50 km. The problem is in the diode rectifier block, replace it.

'92 Si VTEC · Post by **jjmartin349571** » Wed Mar 12, 2014 6:55 pm

I'm just charging my 4g now to have a check of the voltage at idle. Coincidentally I measured my Accord and Golf's battery voltages at the weekend - both roughly 12v when turned off and just over 14v at idle.

batkosio · Post by **batkosio** » Wed Mar 12, 2014 7:07 pm

jjmartin349571 wrote:just over 14v at idle

That means you`re fine

Post by **RattyMcClelland** » Wed Mar 12, 2014 7:13 pm

Need to check my alt ground 1st actually.

BMCC · Post by **BMCC** » Thu Mar 13, 2014 8:26 am

I had a flat battery as the lude was sitting for a few weeks whikle I sorted the fuel line and power steering line. I left the boot open all night when fitting the coilovers a few yrs ago and it ain't been the same battery since. It was charged up over night.

Now when it was fully charged the volts were showing up as 15.2V with the battery out the car. In the car and charging at fast idle it was nearer 17V. At normal idle I would have thought closer to 14-15V. I was suprised to see 17V on fast idle though! I'll need to check that again

Post by **RattyMcClelland** » Thu Mar 13, 2014 9:19 am

I need to try a new battery. But mine is a stinger spv44 deep cycle agm battery. Charging it on the wall is around 13.8 to 14. Charges fine off the wall.

Post by **Merlin** » Thu Mar 13, 2014 9:23 am

What does your alternator output?

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Thu Mar 13, 2014 10:07 am

BMCC wrote: Now when it was fully charged the volts were showing up as 15.2V with the battery out the car. In the car and charging at fast idle it was nearer 17V. At normal idle I would have thought closer to 14-15V. I was suprised to see 17V on fast idle though!

Something not right there. You'll start burning things out at that voltage. 5v above nominal might not sound much, but it's actually nearly 50% increase! Cars should be around 12v on battery only and around 14v with engine running/charging and that should be stable throughout the rev range - increasing engine speed should make no difference.

Supercharged 無限MUGEN BB1 Profile · Post by **nucleustylzlude** » Thu Mar 13, 2014 3:30 pm

That all sounds fine Scott. My battery (a little Odyssey PC680) holds 12.7V engine off and usual charging volts are usually 13-14V.