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Low voltage cutoff module(what voltage to set it to)

Posted: 25 Oct 2015, 14:07
by dave friday
Afternoon all,as above what voltage do l set it to? At the mo' it's set to 10.5volts!!
Ta.

Re: Low voltage cutoff module(what voltage to set it to)

Posted: 25 Oct 2015, 17:36
by Oldiebut goodie
You takes a choice -

Image

Re: Low voltage cutoff module(what voltage to set it to)

Posted: 25 Oct 2015, 17:58
by keytouch
Also how confident are you of its accuracy?
My LVD and solar controller show different readings for the battery by 0.4V

Re: Low voltage cutoff module(what voltage to set it to)

Posted: 25 Oct 2015, 18:19
by dave friday
Thanks Oldie.Keytouch good point,I'll set the voltage with a high impedance volt meter.

Re: Low voltage cutoff module(what voltage to set it to)

Posted: 26 Oct 2015, 08:44
by ghost123uk
keytouch wrote:Also how confident are you of its accuracy?
My LVD and solar controller show different readings for the battery by 0.4V
A good point :ok
dave friday wrote:Thanks Oldie.Keytouch good point,I'll set the voltage with a high impedance volt meter.
:ok

I have mine set to a fairly low value of 11.6, but I don't think it has ever actually fallen that low and tripped off. I tested the trip off voltage by using my big adjustable bench power supply, slowly winding it down until it tripped. This proved to me that my LVD has an accurate voltage setting. I realise most folk don't have access to adjustable bench power supplies though, so best err on the safe side and set it to say 12.2V?

p.s. on the subject of Volt meter accuracy, those little (cheap) panel mounted Volt meters you get off Ebay etc are often miles out, making them "not useful" when needing to check accurate charging voltages or minimum battery voltages. Best check them against a know good "proper" multimeter ;)

Re: Low voltage cutoff module(what voltage to set it to)

Posted: 26 Oct 2015, 09:32
by nicq
Are the setting a no load setting or under load.
No load settings are of little use as the voltage reading neaded are when you have a load attached, or is there very little difference.

Re: Low voltage cutoff module(what voltage to set it to)

Posted: 26 Oct 2015, 19:44
by ghost123uk
nicq wrote:Are the setting a no load setting or under load.
No load settings are of little use as the voltage reading needed are when you have a load attached, or is there very little difference.
That has recently been mentioned on here. The cut off voltage would normally only get activated when under a load, and yes, some folks have pointed out that after a short "rest" the voltage naturally creeps up a bit. However, we are only talking about point something of a Volt, so, to err on the side of safety (for your battery) maybe best to not wory too much and set it for around 12 Volts.

Re: Low voltage cutoff module(what voltage to set it to)

Posted: 06 Nov 2015, 09:09
by California Dreamin
As said..12 volts would be about right, which according to OBG's guide equates to around 50% of the batteries charge. I guess the issue here is peoples perception of battery usage in other pieces of equipment such as phones and rechargeable drills etc, where we will often allow them to be discharged to a completely flat state in order to ensure a full re-charge cycle the next time (the old memory effect on Ni-Cad batteries and brought about that way of thinking) However, we must treat car batteries completely differently because damage can often occur if the cells are allowed to discharge and are left at anything less than 12 volts.

So in a way the capacity (amp hour rating) becomes even more important as only 50% of the charge is usable.

The other important point here is: if you do accidentally fully discharge your battery, charge it STRAIGHT AWAY! it maybe recoverable if 'sulphation' hasn't started to occur.



Martin

Re: Low voltage cutoff module(what voltage to set it to)

Posted: 06 Nov 2015, 22:13
by CovKid
Seconded. As Martin will recall, I flattened my leisure battery down to just 5 volts at Stapleford. I recharged it immediately and its been fine ever since but left in too low a state of charge for too long, damage occurs. 12v sounds a good minimum.

Re: Low voltage cutoff module(what voltage to set it to)

Posted: 07 Nov 2015, 08:47
by ghost123uk
I got one of those very cheap controllers ( LINK). I don't use it in the van, I have a better system of my own for that. I have it set up at my mates allotment / party / BBQ venue. The stupid thing is not adjustable and cuts off at 12.45 Volts :roll: (So I only use the charge controller function of it).

Re: Low voltage cutoff module(what voltage to set it to)

Posted: 21 Apr 2017, 20:42
by hardwick53
I need to replace my leisure battery and at the same time I will change the split charge relay to the lucas SRB630. I am thinking of fitting a LVD off fleabay http://www.ebay.co.uk/itm/12V-battery-l ... W2cmPqSfqQ" onclick="window.open(this.href);return false;

My question is where is best to position/mount the LVD?