Headlight question

[V4bandit]

Hey guys, just a quick question. On my 85 Vmax I have done the R/R wire mod . Red wire direct to batt. with 30 amp fuse. and direct ground wire to frame / batt. Charging is up to 14.2 VDC at idle. When the headlight is on though the charging volts drop to 12.3 VDC. Is this normal?

 

[95spfldmax]

Hey guys, just a quick question. On my 85 Vmax I have done the R/R wire mod . Red wire direct to batt. with 30 amp fuse. and direct ground wire to frame / batt. Charging is up to 14.2 VDC at idle. When the headlight is on though the charging volts drop to 12.3 VDC. Is this normal?

At idle i'd say ok. But 2-3K RPM or more s/b back to low 14's in a prefect world..............

 

[94 V-Max Rider]

Hey guys, just a quick question. On my 85 Vmax I have done the R/R wire mod . Red wire direct to batt. with 30 amp fuse. and direct ground wire to frame / batt. Charging is up to 14.2 VDC at idle. When the headlight is on though the charging volts drop to 12.3 VDC. Is this normal?

The voltage is going to drop when loads are applied. The real question is, what is your meter showing at 1500 RPM? At break-even speed it should show 14-14.5 VDC, ideally.

 

[wildweasel_pt]

Should never go below 13v with everything on including fan... A good charged battery should read around 12.9v on standby.

 

[V4bandit]

The battery is brand new and only reads 12.54 v after the initial charge. I will check the readings @ 1500rpm and again @ 3000 rpm. See what it says. Thanks for help , I'll let ya's know what I find. Oh also the headlight bulb is the stock size ( 55/ 60 watt ? )

 

[KJShover]

Where are you drawing the feed for the volt meter?
With my old digital I used a gauge light. I read about 1.2v lower than I actually was with the hand held meter.

 

[MaxMidnight]

The battery is brand new and only reads 12.54 v after the initial charge.

The battery voltage should not be taken immediately after charging (or running the bike) as there will be a 'surface charge'
This needs to be dissipated before an accurate voltage reading can be obtained.
If the battery is still on the bike then turn the headlight on for a couple of minutes or if off the bile allow the battery to stand for eight hours or so.

The voltage of a completely charged battery depends on the construction:
Conventional = 12.6
Gel = 12.85
AGM = 12.8

A reading of 12.54 could be down to a poor battery charger or a slightly inaccurate or calibrated voltmeter.

The acid test (if you will pardon the pun) is a) does it hold the charge and b) will it reliably start the bike.

If the answer to both of the above is yes then don't worry and enjoy the bike! :eusa_dance:

 

[V4bandit]

I took the readings direct from the battery terminals about 1 day after the charge was completed. I haven't had a chance yet to do a reading with the bike at different rpm's , but the battery doesn't seem to have any issue starting the bike at all. I just completed my carb sync and had to start / stop the bike a few times and she rolled over quickly and fired every time. I might just be worried to much. Vmax's are a new breed to me. I should just enjoy the beast.

Also my digital meter is a cheap $13 or so model from Canadian Tire that I have had for a few years. I should have brought my Fluke home from work. lol

 

[V4bandit]

I finally got the bike out and running today. Checked the voltage at the battery while idle and at 3000 rpm. Both times I got 14.3 V. I did pull the headlight bulb and check / crimp down the connections a bit. Maybe that helped ???? Anyway, I'm not worried now, time to ride!