Voltage Problem

SteveGB · June 12, 2011, 07:14:57 CET

Hi Guys,

Not sure if anyone out there can help me with this. Hopefully yes!

I just installed a new fixed VHF on my boat (Garmin IC 411)

I now noticed that when I i press the transmitter button to talk on the VHF my Voltage goes down to 10.8V/11V from the normal 12.2V. The change in Voltage can be seen on my Garmin GPS. Now is this normal??, do i need to worry that the GPS and other equipment won't function well when this happens or that my motor would not start someday when im out there?

I just charged the battery as i do at the beginning of every summer using a trickle charger and it shows Green on the indicator. This battery is approx 6/7 years old and is a Maintenance Free, Sealed Delphi Battery 12V 80Ah with the following specifications: CCA(-18 Degrees Celsius) BCI 800 IEC 480 DIN 440 EN 760.

can it be that this battery is near the end of its useful life??

I used other batteries to check if my battery is the problem, but the same happens.

I have Lights, Bilge pump, Shower, GPS, VHF and a Stereo on my 19.5 ft boat. Obviously these will never be on all at once. (just maybe the stereo, VHF and GPS). I know that its best to have two batteries, but I do not want my boat to get any heavier then it already is

Hope someone can help,

thanks,

Steve

benri · June 12, 2011, 08:28:20 CET

In my opinion it's time to change the battery after 7 years moreover when you are not carrying a spare.
It is normal for the voltage to dip a bit when you're transmitting on high power but I'm not sure whether it should drop that much!

toxictuna · June 12, 2011, 09:49:25 CET

99.9% you have a non solid electrical connection somewhere, causing resistance hence a voltage drop when you load the circuit. Check connectors, fuses, etc for signs of rust, oxidization, deteriorationm. Tighten all bolts too

The_Gaffer · June 12, 2011, 10:32:30 CET

6-7 years service is very good for a battery used at sea. I would recommend changing the battery now. But that's not the reason for your voltage drop. As benri and toxictuna suggests, check all connections for signs of corrosion, loose contacts ect

Destination Sea · June 12, 2011, 10:56:56 CET

as above. usually when cranking a motor engine the battery might get down to that volts, wonder whether just transmitting it should do the same. Check that you dont have any wing nuts on the terminals and all is clean and sound. Most probable is that the battery is starting to get one cell in isolation (Tinqatta cellola) and losing volts under load.

Moonwalker · June 12, 2011, 11:21:38 CET

If the voltage does not drop when starting the shower or bilge pump then it is not a battery problem.
It must be a bad connection somewhere as stated above but if you cant locate it, just give more details how the wiring from battery to utilities is done.

offken · June 12, 2011, 11:25:21 CET

Check all the earthing system because that mite be the problem

Granitu · June 12, 2011, 11:38:38 CET

'for all connections ideally use shriking tubes and materials that reduce air contact at sea. Air at/by the sea has high moisture levels'

this is a tip i got from my sister's boyfriend - he is an electrical engineer at freeport - and wiring tape is not enough

Moonwalker · June 12, 2011, 11:52:31 CET

Shrinking tubes help but not enough.
Best way is to have all connections soldered in place.
For the connections where solder is not an option then plastic spray is very good to seal off the water.

SteveGB · June 12, 2011, 18:42:11 CET

Thanks guy for your suggestions.

I used another marine battery to check and the same happened, so i guess or i have a problem with my wiring or its normal that there is such a drop in voltage. I checked on the VHF manual and its says that at TX high the current drain is 5.5 A max.

Im not sure how my wiring is done as not I wired it up, but everything is connected to one lead which goes to the battery i guess. I have no distribution box etc....

I will try take my current battery to the agent so that he can check it out but i doubt its a battery problem as it shows green in the indicator. Any problems I will buy a new battery to be on the safe side. DOES ANYONE KNOW WHO IS THE AGENT FOR DELPHI BATTERIES IN MALTA?

??

I have another battery which i use for electric reel, http://www.hefra.nl/docs/webshop.asp?act=item&itemcode=VDC31M but they told me that this is not good to be used a starter battery etc as its deep cycle.

Thanks again,

steve

toxictuna · June 12, 2011, 19:01:07 CET

I think its strand marine near crosscraft/flamingo. however its not a battery prob.

Moonwalker · June 12, 2011, 19:19:50 CET

1 - If the Voltage drop does not happen when you switch ON the bilge pump/shower, the problem is not the battery.
2 - If the VHF was installed by someone else ask him again to check the connections/wiring.
3 - If you installed it yourself you must have connected the with the wrong wire/connection.

shanook · June 12, 2011, 19:51:08 CET

first check the connection of the airial. Make sure you have a sound connection. since u said its in the TX mode.

skip · June 12, 2011, 23:12:34 CET

1) Install a ferrite ring on the power cables.
2) Check routing of the power cables, what are they passing near
3) VHF should be wired straight to the battery terminals for safety reasons with an in-line fuse. Is yours like this?
4) Speak to me tomorrow at work Steve

5) Delco is now Cambros near Flamingo
6) Strand Marine are doing Varta (who bought Delphi) and they also do Optima and Mastervolt batts

Villager · June 13, 2011, 11:55:30 CET

icekja bil meter ara hux min mal battery dirett qed jaqa il voltage .... jekk le mux problema ta battery .... jekk tara li mux problema ta battrey addi linja gdida ta wires min mal battrey al mal gps dirett jew hu pacezja ara fejn em tape, bulets jew slider u ibdilom ax ximkien qed jitlef ! nispera li kont ta ajnuna !