Buzzing Noise in Voltage Box

Turka · Newbie

Buzzing Noise in Voltage Box

PeterD · Guru

What is the "Voltage Box" you are talking about? Which fuse are you taking out? Are you smelling any burnt electrical smell? If you are talking about the Setec power supply, the fuse you are talking about is the fuse to the battery and removing the fuse stops the buzzing then you may get away with things. However, the Setec power supply supplies the 12 V power to your lights. If there is something packing up you also may lose your lighting. It may be safer to switch the power off to the setec and use some other form of lighting whilst you are away.

patrol03 · Senior Member

Hi Turka. The voltage box you speak of is most likely the battery protector. It usually has three settings which will determine the battery cut off point and so protect it from being fully discharged which is detrimental in most cases to deep cycle batteries particularly AGM's. From the sound you describe I would suggest that your battery is well past recovery.It certainly looks like a new one. While deep cycles lose charge very slowly in storage they should have a charger on them all the time so that they stay in a float situation.This will extend the life of a battery. Deep cycles well looked after should last for many years without trouble. Cheers

Possum3 · Guru

When things go wrong or start making strange noises it is time to visit a Auto Electrician that knows about caravans,
$100 spent now could save you being toasted in your sleep.

Roy E · Senior Member

Turka,
I don't know if I'm missing something here or everyone else is but as I see it, your battery at 10.5 volts is stuffed and a good starting point to suss out your power supply "buzzing noise" problem would be to fit a fully or well-charged battery and see if the "buzzing" continues.
Cheers,
Roy.

Mike Harding · Guru

Bees?

Buzzing in electrical systems is usually caused by the laminations in a transformer vibrating. A few things can cause this but in a new-ish system it may well be a very high magnetic flux caused by the transformer carrying a high current. Given the condition of the battery you describe the charging circuit may be working at full load. If the buzzing goes away forget about it, if it doesn't have the battery checked and proceed accordingly.

Next time: keep the battery on float charge if you intend to leave it unused for months.

Warren-Pat_01 · Guru

G'day Turka,
Welcome to the forum - here is a wealth of info here in this forum either alive or in the "Search" area. I trust you will enjoy your time here.

Now for the not-so-good info - as the others have said your battery is stuffed. Have a read of this www.energymatters.com.au/components/battery-voltage-discharge/ & if you can find 10.5v on the chart, you're better than me!

HOWEVER - all is NOT lost - yet. You said you have charged it up to 10.5v - what was it before? If you can lay your hands on an old type say10-15A battery charger, disconnect the battery in the van & put the old charger on it. I MIGHT go to 13.2 to 13.5v. Take the charge off & let the battery settle for 30 mins. Measure the voltage, it might have dropped to 12.8v. Find a 12v globe eg a blinker (21w) or a headlight (55w) & put that on the battery.

Measure the voltage each 15 mins - when it gets to 50% capacity(12.2 to 12.3v) stop the discharge & charge it up again. Repeat many times & finally put a separate smart charger it. You might be lucky & save $3-400 immediately. I rejuvenated a "stuffed" battery with less than 2v on it this way! It took me three weeks!

You need to either keep it on charge or get a portable solar panel with a suitable controller mounted near the battery (not on the panel) & keep that on the battery. It doesn't matter whether the panel goes out of the sun sometimes during the day.

You have a couple of years before retirement - time to learn about your van. Ask for help if you need it - did you get the manuals with it?
The SETEC system in your van is a smart charger - but for this exercise, use a separate one (borrow one if need be).

Mike,
I thought you were going to start talking about Gauss & Maxwells! I don't think the el-cheapo transformers they use these days have laminations that will vibrate - LOL. But yes, you're right!

PeterD · Guru

Warren-Pat_01 wrote:
You have a couple of years before retirement - time to learn about your van. Ask for help if you need it - did you get the manuals with it?
The SETEC system in your van is a smart charger - but for this exercise, use a separate one (borrow one if need be).

The Setec is not an efficient battery charger. Its output voltage is not high enough for it to be a battery charger. The handbooks for all three models contains the following wording.

AC/DC Power Supply: This provides an isolated 13.65Vdc output for powering of the load and
float charging of the battery. Battery current is sensed and monitored by the power supply to ensure
that the maximum charging current is not exceeded.

You will see it only says "float charging." It does not mention anything about bulk charging of batteries.

Warren-Pat_01 · Guru

G'day PeterD,
I beg to differ - I did some tests one night with Tony (Tony-Bev).
Tony was of the same opinion as you - that it was only a trickle charger & not going above 13.7v. That was for the first series as I had in my Eagle. It was flat out at 5A & was designed to be a trickle charger only. I did investigate updating but at $600 & having Scottish blood in me I decided to give that offer up.

The latter series (2 or 3, can't recall - is out in the van) that is in my 2011 van & I assume is the same as Terry has in his Expander is capable of charging at 30A & 14.4v.
I discharged my battery (headlight bulbs are handy) for a few hours, monitoring the battery voltage every 15 & later 30 minutes after it stabilised. I took it down to 12.5v & turned the charger on, noting that the SETEC charger performed as I expected it to. Not perfect but it certainly packed a punch when called on. Mind you, to get a cct diagram out of SETEC is impossible - they are frightened that we'll go in competition, I guess.

I still carry an 8A, 7 stage smart charger with me in the van, connecting to the battery every now & then as required - perhaps it is better than the SETEC, I don't know. If we were all richer, Jayco would have gone out of business years ago! At least I can monitor the stages of charge with the smart charger.

PeterD · Guru

Warren-Pat_01 wrote:
The latter series (2 or 3, can't recall - is out in the van) that is in my 2011 van & I assume is the same as Terry has in his Expander is capable of charging at 30A & 14.4v.
I discharged my battery (headlight bulbs are handy) for a few hours, monitoring the battery voltage every 15 & later 30 minutes after it stabilised. I took it down to 12.5v & turned the charger on, noting that the SETEC charger performed as I expected it to. Not perfect but it certainly packed a punch when called on. Mind you, to get a cct diagram out of SETEC is impossible - they are frightened that we'll go in competition, I guess.

This is what both the ST-II and ST-III handbooks read:

Battery Features: The power supply provides full battery management as per the following.

The power supply is a four stage battery charger with Boost (VBoost = 14.05V), Float (VFloat =
13.65V), Store (VStore = 13.25V) and Trickle charge modes to ensure long battery life.

Battery Charging current is limited to a maximum of 10A (ST20-II) and 15A (ST35-II). This
provides optimum life for the batteries.

However, when you examine their charging curve you will see that the VBoost of 14.05 V only occurs for 15 minutes after the first 48 hours and 15 minutes every day after that. Apart from that the maximum sustained voltage is 13.65 V. This is hardly likely to charge a battery in a reasonable time.

As for your 30 A max charging current, the handbook suggests 10 or 15 A max depending on the model. The 20 and 35 in the model numbers refer to the maximum combined output current for the load together with the battery charging current.

I have not done a full research to check whether your assertions or the Setec handbook are correct. I will put my money on Setec being correct

Setec charging curve.GIF

-- Edited by PeterD on Monday 8th of October 2018 03:14:30 PM

Aus-Kiwi · Guru

Pulsing reg ? Mine has done similar on cool suny days . I assume the solor panels are charging too much . Unless youve jammed the Mrs finger . But I guess you would hell know you have !! Lol