New leisure battery, is it ok question

[saltyrob]

Hi folks,

Having fitted a new Exide ET650 battery and as noted in recent post connected to a solar panel and mppt solar charger gave it a trial run. Last night after dark checked the battery with a multi meter and it read 12.71 volts so fully charged ,switched on a couple of interior lights for an hour , with all charging turned off and the voltage dropped to 12 .44 volts. I appreciate some advice as to whether this is ok or there is an issue with the battery. The battery serves only equipment and will not be used for engine starting.

Many thanks

Rob

 

[Daverw]

Are the lights LED?

 

[saltyrob]

About 1.8 m of led strip and two halogen downlighters

 

[Alex_Blackwood]

About 1.8 m of led strip and two halogen downlighters

What wattage?

 

[johnalison]

My batteries usually hold around 13v for a while after charging, so I wouldn’t regard 12.7 as fully charged, but I’m no electrician and can’t answer the question, but it sounds as if something is not right.

 

[peteK]

I would of expected the battery to return to 12.7v after lights were switched off with your 100ah battery.

 

[saltyrob]

Hi Alex , sorry I don't know the wattage but the're the usual small type fitted in smallish boats ,if that's any help .

 

[saltyrob]

Should have added ,checked the electrolyte levels before fitting and gave them a charge with my Ctek before fitting

 

[wingcommander]

You will be measuring the surface voltage. Need to let batteries rest for an hour with no draw or charge then re check . A good battery will settle back around 12.7v . Provided your not powering your local football team floodlights.

 

[Boater Sam]

12.7v is not fully charged. What was the final current when on charge?

 

[PaulRainbow]

12.7v is not fully charged. What was the final current when on charge?

Nonsense, a rested battery showing a voltage reading of 12.7v is fully charged.

 

[VicS]

Hi folks,

Having fitted a new Exide ET650 battery and as noted in recent post connected to a solar panel and mppt solar charger gave it a trial run. Last night after dark checked the battery with a multi meter and it read 12.71 volts so fully charged ,switched on a couple of interior lights for an hour , with all charging turned off and the voltage dropped to 12 .44 volts. I appreciate some advice as to whether this is ok or there is an issue with the battery. The battery serves only equipment and will not be used for engine starting.

Many thanks

Rob

12.7 to 12.8 volts is the expected fully charged voltage for a rested wet cell battery.
( 12 .8 to 12.9 for an agm battery)
Cannot comment on the voltage under load without knowing the current but if it recoverd to near 12.7 all is well.
Did you measure the voltage directly on the battery posts with a reliable multimeter?

 

[alahol2]

I tend to use the attached table... It seems to work with my (similar to your) setup.
Incidentally, LED strip can use surprisingly more current than you may expect.

 

[Daverw]

Also the halogen lamps can be quite power hungry

 

[Alex_Blackwood]

I tend to use the attached table... It seems to work with my (similar to your) setup.
Incidentally, LED strip can use surprisingly more current than you may expect.

If the OP can compare that chart with the amps of his lighting he may get an answer. I note V @ 5 amps 12.4!! If he has a couple of 24 watt halogens and his LEDs not far out. Even at 90% 12.3!
I don't think I would be getting excited with his figures and a "Wet Finger" measurement.

 

[saltyrob]

Really appreciate your replies and using the above info feel much happier.

Cheers

Rob

 

[Daydream believer]

I tend to use the attached table... It seems to work with my (similar to your) setup.
Incidentally, LED strip can use surprisingly more current than you may expect.

Why does that chart show a battery at 100% charge rested as 12.8V
But at 0A still at 100% charge it shows 12.5V
How come it is showing .3 V less but nothing drawn from the battery
What am I missing please?

 

[Yorkshire Exile]

What a lovely chart. I'm going to print it out and keep it with me at all times!!!!

I tend to use the attached table... It seems to work with my (similar to your) setup.
Incidentally, LED strip can use surprisingly more current than you may expect.

P.S. Does purple indicate buggered?

 

[Boathook]

Why does that chart show a battery at 100% charge rested as 12.8V
But at 0A still at 100% charge it shows 12.5V
How come it is showing .3 V less but nothing drawn from the battery
What am I missing please?

Rested means around after an hour as mentioned in another post. I assume the other one is just after the load is turned off which makes sense.

 

[alahol2]

Why does that chart show a battery at 100% charge rested as 12.8V
But at 0A still at 100% charge it shows 12.5V
How come it is showing .3 V less but nothing drawn from the battery
What am I missing please?

I've always taken it to mean that there is a small current being drawn, maybe up to an amp.