Battery - run down rate

[Colinn]

I wonder if some of you technical experts cd comment on my battery state.

I had a new 110 ampere battery fitted in October and conscious of the need to keep it topped up I was prepared to charge it every three weeks or so over autumn/winter.

However, after the first three weeks, and during this current cold spell, I went to check it ready for charging and found it was down to only 8volts. Absolutely everything was off, but it wouldn't even register on my control panel or fire up the radio.

It charged up again, no problem, but i wonder, is this as good as it gets. Or should I have any suspicions about the battery?? Tks.

 

[RogerL]

Check whether the cells need topping up, this could cause very low voltage readings but would also be indicative of a faulty charger / power supply.

Are you sure that nothing is being left on, like the TV aerial amplifier?

If a 12v battery goes below about 11v, with no external cause, it indicates that a cell has failed, in a newish battery, or that all the cells are failing in an older battery.

You may need to return it to the supplier for a replacement if it's faulty.

 

[mcghee]

i would say keep a check on the specific gravity of each cell,they should all be roughly equal.if theyre not the plates may be bent in one or more cells,this happens when batteries are discharged heavily.meaning that when the battery is trickle charging the voltage cannot equalize and will fall away quickly.also,can you guarantee your charger is ok?

 

[rob_jax]

Hi Colin,

If your leisure battery was totally disconnected from everything, the self-discharge rate is around 50 to 100mA per hour, say around 1 or 2 Amp-Hour equivalents per day.

So your 110 AH battery should go from fully charged to dead flat in between 100 and 50 days. But I tend to agree with Roger and Craig, sounds like something else is on drawing around 100 mA and the TV aerial amplifier is a good guess.

It's quite important that you keep the battery charged at around 50% to 100% of capacity, because when fully charged the battery liquid freezes at around -30

 

[WatsonJohnG]

Could that something be an alarm/tracker system??

 

[Colinn]

Thanks guys, it sounds as if you have answered my main question, ie, should i be suspicious about the battery, and clearly i shd!

To answer the various points.

1) the battery is brand new;

2) So is the charger;

3) Alarm is fitted but it's not set;

4) aerial amplifier definitely switched off;

5) N

I haven't checked the cells because it's so new, but i will now and if i can still see my problem i guess i'll have

 

[Colinn]

Thanks guys, it sounds as if you have answered my main question, ie, should i be suspicious about the battery, and clearly i shd!

To answer the various points.

1) the battery is brand new;

2) So is the charger;

3) Alarm is fitted but it's not set;

4) aerial amplifier definitely switched off;

5) N

I haven't checked the cells because it's so new, but i will now and if i can still see my problem i guess i'll have

Sorry, hit the wrong key and submitted this before I'd finished,

Last part shd read:

5) No Tracker fitted.

I haven't checked the cells because it's so new, but i will now, and if i still have a problem i guess i'll have to contact the main dealer who installed it.

Tks.

 

[SteveW77]

Most alarm systems draw power even when they are not activated, this could be the cause of your problem.

Steve W.

 

[Richard_5040072]

We had the problem of the battery only seeming to last a short while on a quite new van and had the dealer check everything. He thought it was the radio/CD which, even though switched off, was causing a drain on the battery.

We have now fitted a switch in the 12v circuit to the radio to cut it out when not in use.

It would be worth checking to see if the radio is on "standbye" when the van is not being used.

 

[Colinn]

We had the problem of the battery only seeming to last a short while on a quite new van and had the dealer check everything. He thought it was the radio/CD which, even though switched off, was causing a drain on the battery.

We have now fitted a switch in the 12v circuit to the radio to cut it out when not in use.

It would be worth checking to see if the radio is on "standbye" when the van is not being used.

The radio is certainly on standby to display the clock under normal "off" circumstances, but i can switch it completely off on my control panel, so it's not that. Tks.

 

[Colinn]

I've just re-checked the control panel, aerial amplifier, radio, alarm etc, and everything is off. The voltage drain indicator was showing 0.3 with the radio on standby, so i removed the radio fuse and the indicator read 0.0d (presumably, this replicated the situation with the caravan electrics switched off). So I think I may have a less than perfect battery - the reading's down to 11.8vs after 24 hours.

 

[RogerL]

You now need to establish beyond doubt whether its a faulty battery or unexplained drain.

Fully charge the battery, I'd suggest 48 hours given your low voltage reading. Disconnect the battery completely from everything and let it rest for 6 hours. Then check the voltage with a digital voltmeter. In these conditions a poor battery will show 12.5v or less while a good battery will show 12.7v. An aging battery might well be near the 12.5 but your virtually new battery should be around the 12.7.

If your battery shows 12.5 or less, take it back to your supplier, tell him how you've tested it and get a replacement, or a refund.

 

[Colinn]

You now need to establish beyond doubt whether its a faulty battery or unexplained drain.

Fully charge the battery, I'd suggest 48 hours given your low voltage reading. Disconnect the battery completely from everything and let it rest for 6 hours. Then check the voltage with a digital voltmeter. In these conditions a poor battery will show 12.5v or less while a good battery will show 12.7v. An aging battery might well be near the 12.5 but your virtually new battery should be around the 12.7.

If your battery shows 12.5 or less, take it back to your supplier, tell him how you've tested it and get a replacement, or a refund.

Many thanks, I'll try that...can I consider my caravan control panel to be a reliable digital voltmeter??

 

[WatsonJohnG]

You may have a lead to the radio to the memory circuit which is direct from the battery as I have.

 

[laurieW]

Hello Colin.I had exactly the same problem on our brandnew Senator Arizona(2002).This also had a new 110amp/hr fitted.The battery went flat in about 4 days whilst in store with everything switched off.Never had probs before with other vans.I used a multimeter to find the "leak".The biggest drain was the motormover(no isolating switch...see other thread).I also had a drain to the alarm(even though the alarm had its own battery and was not set).I also had a drain to the habitation relay.I also discovered that:if I switched off the 12v switch to isolate the van electrics completely, the fridge would drain the battery if the fridge was left swithed to 12volts.

I then disconnected the leisure battery whilst in store.

I then bought a Senator Oklahoma(2004)and fitted an isolator switch to the mover(same mover).This van uses a different alarm.

I have had no problems with this van,although the fridge will still discharge the battery if fridge is left on 12v when master switch is off,(Bailey aware of this...mentioned in handbook).My battery does not now discharge whilst van in store.

 

[RayS]

Suggest you get the very good leaflet from CC (as a download) assuming you are a member. You have not said whether you are charging with the built in charger for the caravan or with an ordinary trickle charger. It seems that the latter may easily damage leisure batteries bu over charging causing sulphating. The tell yu not to let the terminal voltage of a leisure battery on charge go above 14.1 volts. This may mean charging for shrort periods and then letting the battery stand.##

I think I may have done this to a new leisure battery bought last year in Spain and that it is now down in effective capacity to about 30 amp-hours rather than the rated 90. The sysmptoms are that it holds a charge while disonnected but discharges very rapidly with any serious load e.g. a mover.

I also have figure which show that a fully charged "good" battery should be showing 12.8v or more after standing disconnected for 12 hours. 12.5v indicates 75% charge 12.2v 25% and 12 or below flat.

 

[WatsonJohnG]

laurieW that's very interesting about the fridge on 12V discharging the van battery when parked and unhooked.

It must be feeding back in some as 12V on tow is only from the car battery direct via a relay and not from the van battery.

I look forward to reading that in the Oklahoma handbook when we get it but thanks for the early warning!!

 

[RogerL]

Colin - you'll need a digital voltmeter NOT the caravan voltmeter.

A digital voltmeter is normally accurate to +/- 0.005 volt so will let you measure tenths. A caravan voltmeter, with a swinging needle, is only accurate to about +/- 0.25 volt so would not help in this exercise.

 

[Colinn]

Hello Colin.I had exactly the same problem on our brandnew Senator Arizona(2002).This also had a new 110amp/hr fitted.The battery went flat in about 4 days whilst in store with everything switched off.Never had probs before with other vans.I used a multimeter to find the "leak".The biggest drain was the motormover(no isolating switch...see other thread).I also had a drain to the alarm(even though the alarm had its own battery and was not set).I also had a drain to the habitation relay.I also discovered that:if I switched off the 12v switch to isolate the van electrics completely, the fridge would drain the battery if the fridge was left swithed to 12volts.

I then disconnected the leisure battery whilst in store.

I then bought a Senator Oklahoma(2004)and fitted an isolator switch to the mover(same mover).This van uses a different alarm.

I have had no problems with this van,although the fridge will still discharge the battery if fridge is left on 12v when master switch is off,(Bailey aware of this...mentioned in handbook).My battery does not now discharge whilst van in store.

Thanks for that. True, I have just had a motormover fitted, but it does have an isolator. Fridge is definitely in off position. I'm going to try a full 48 hour charge and let the battery stand totally disconnected to see how it holds charge then. Tks.

 

[Colinn]

Suggest you get the very good leaflet from CC (as a download) assuming you are a member. You have not said whether you are charging with the built in charger for the caravan or with an ordinary trickle charger. It seems that the latter may easily damage leisure batteries bu over charging causing sulphating. The tell yu not to let the terminal voltage of a leisure battery on charge go above 14.1 volts. This may mean charging for shrort periods and then letting the battery stand.##

I think I may have done this to a new leisure battery bought last year in Spain and that it is now down in effective capacity to about 30 amp-hours rather than the rated 90. The sysmptoms are that it holds a charge while disonnected but discharges very rapidly with any serious load e.g. a mover.

I also have figure which show that a fully charged "good" battery should be showing 12.8v or more after standing disconnected for 12 hours. 12.5v indicates 75% charge 12.2v 25% and 12 or below flat.

Tks, I am going to give it a good charge and let it stand as suggested. I am a CC member so I will look for that leaflet. The charger is newly fitted in the van by a main dealer.

 

[Colinn]

Colin - you'll need a digital voltmeter NOT the caravan voltmeter.

A digital voltmeter is normally accurate to +/- 0.005 volt so will let you measure tenths. A caravan voltmeter, with a swinging needle, is only accurate to about +/- 0.25 volt so would not help in this exercise.

Tks Roger, My caravan voltmeter is digital. I'm not great at understanding electrical things, for example, would the caravan voltmeter register, say, a drain from the motor-mover which although it has an isolator switch obviously is an after-fit and perhaps not part of the control panel. Or does the van voltmeter register battery drain from any load?

In any event, I intend to give it a 48 hour charge at the weekend and then disconnect it to see how long it retains the charge. Reading was down to 11.4 tonight!

 

[RayS]

Colin - you'll need a digital voltmeter NOT the caravan voltmeter.

A digital voltmeter is normally accurate to +/- 0.005 volt so will let you measure tenths. A caravan voltmeter, with a swinging needle, is only accurate to about +/- 0.25 volt so would not help in this exercise.

Sorry to be pedantic but a digital voltmeter may not be as accurate as it appears. True the display will show this sort of "accuracy" but the true figure is likely to be very much lower. I have two of normal commercial quality and they can show up to 0.25 volt difference when applied at the same time. It's almost the same syndrome as getting 10 decimal places on a hand calculator.

I agree a top grade professional meter is much better but doubt that many readers will be using this quality of equipment - far too expensive.