Leisure Batteries - Are they on their way out?

[Nick-Mandy]

Hi,
We have two 110mAh standard Leisure batteries (plus the vehicle battery). They are 3 years old and never gone under 10 volts which I believe is around 75%.We have three Solar panels of 420 watts (which might need a clean but ....)
The problem we are having lately is, from a full charge and only using around 39 watts, our battery power off grid is only lasting around 4 and a half hours, compared with the winter months, they last around 6 hours in complete darkness. Charging the batteries is no problem with both vehicle power and around 11 watts in dull weather.
Do you think our two batteries require changing?
If so, would replacement of one lithium battery be an advantage?

 

[Pedalman]

If a battery goes down to even 12v that is 50%, 11 volts is about 40% ....10 volts is terminal.

 

[Exwindsurfer]

Hi,
We have two 110mAh standard Leisure batteries (plus the vehicle battery). They are 3 years old and never gone under 10 volts which I believe is around 75%.We have three Solar panels of 420 watts (which might need a clean but ....)
The problem we are having lately is, from a full charge and only using around 39 watts, our battery power off grid is only lasting around 4 and a half hours, compared with the winter months, they last around 6 hours in complete darkness. Charging the batteries is no problem with both vehicle power and around 11 watts in dull weather.
Do you think our two batteries require changing?
If so, would replacement of one lithium battery be an advantage?

I personally would go for a fogstar 300amp you cam never have to much power.

 

[trevskoda]

12.2v to be safe with standard old hat batteries which at best give 200 cycles, without changing chargers etc best to go lead carbon, 1300 cycles and 50% wont bu--er the cells, and for a short time can be left discharged, cost around £200 for a 115ah unit, 2 would be plenty.

 

[Pedalman]

Worth every penny .

 

[Sonar]

This is one of the reasons we’re going to fit a lithium battery system with the help of member wildebus. David.
Two 280 battery will be on order over the next few weeks along with the final part the battery charger.

 

[wildebus]

Hi,
We have two 110mAh standard Leisure batteries (plus the vehicle battery). They are 3 years old and never gone under 10 volts which I believe is around 75%.We have three Solar panels of 420 watts (which might need a clean but ....)
The problem we are having lately is, from a full charge and only using around 39 watts, our battery power off grid is only lasting around 4 and a half hours, compared with the winter months, they last around 6 hours in complete darkness. Charging the batteries is no problem with both vehicle power and around 11 watts in dull weather.
Do you think our two batteries require changing?
If so, would replacement of one lithium battery be an advantage?

At 3 years old your batteries *should* still be reasonably serviceable. But ... your experience suggests they are basically knackered!

a 100Ah battery is nominally 1200Wh and if you took it down to the voltmeter reading 12V (which is around half the total power taken out out of it), you would have used 600Wh. If you are only getting 4.5Hrs using 40W, that equates to 180Wh used. That is a very small amount of what should be available from a battery in decent condition, and it when you say "only lasting" you are saying the power just goes off as the voltage is dropping so much, your batteries are fit for immediate scrapping and nowt else.
I had that situation with my motorhome after I bought it ... 2 x 110Ah AGM and I lasted one evening!

Stick with Lead is the easiest/simplest option. If you do keep with the Lead Option, strongly recommened Lead Carbon. More expensive but will last maybe 5 times longer than the basic lead, and have many many advantages.
If you go with Lithium, that will give you a better overall result, but you have to consider if you need to make other changes to suit (which is very very likely - no such thing as a "drop in" lithium battery UNLESS your motorhome happens to be lithium-compatible already!)

 

[Nick-Mandy]

At 3 years old your batteries *should* still be reasonably serviceable. But ... your experience suggests they are basically knackered!

a 100Ah battery is nominally 1200Wh and if you took it down to the voltmeter reading 12V (which is around half the total power taken out out of it), you would have used 600Wh. If you are only getting 4.5Hrs using 40W, that equates to 180Wh used. That is a very small amount of what should be available from a battery in decent condition, and it when you say "only lasting" you are saying the power just goes off as the voltage is dropping so much, your batteries are fit for immediate scrapping and nowt else.
I had that situation with my motorhome after I bought it ... 2 x 110Ah AGM and I lasted one evening!

Stick with Lead is the easiest/simplest option. If you do keep with the Lead Option, strongly recommened Lead Carbon. More expensive but will last maybe 5 times longer than the basic lead, and have many many advantages.
If you go with Lithium, that will give you a better overall result, but you have to consider if you need to make other changes to suit (which is very very likely - no such thing as a "drop in" lithium battery UNLESS your motorhome happens to be lithium-compatible already!)

Thank you David,
Well explained.
Still running a few more tests, especially now this evening is sunny and the panels are giving me a great deal more solar power.
I'm plugging in the TV much later for late time programmes, taking note of the discharge rate and length of time from 100%. Obviously the sun will give me extra viewing time early on.

The oven cooling fan needs disconnecting as that uses quite a lot of power.

 

[wildebus]

Thank you David,
Well explained.
Still running a few more tests, especially now this evening is sunny and the panels are giving me a great deal more solar power.
I'm plugging in the TV much later for late time programmes, taking note of the discharge rate and length of time from 100%. Obviously the sun will give me extra viewing time early on.

The oven cooling fan needs disconnecting as that uses quite a lot of power.

Not sure what van you have, but if you have a Truma Combi heater, the fan on that is very thirsty as well!

When I found I had what seemed like a pair of Duracell AA batteries to run the motorhome, had to bring my upgrade plans forward as too limiting to not be able to last more than a few hours.

 

[Nick-Mandy]

Not sure what van you have, but if you have a Truma Combi heater, the fan on that is very thirsty as well!

When I found I had what seemed like a pair of Duracell AA batteries to run the motorhome, had to bring my upgrade plans forward as too limiting to not be able to last more than a few hours.

The fan that runs automatically after using cooker to cool it down, seems to be active for ages and uses a fair bit of power.
We've discovered that turning the whole system.off and opening the door for 5 minutes, cures this without using the battery power.

Something within.our system uses 2 watts up continuously, and have yet to work this out.
Any suggestions?

 

[wildebus]

The fan that runs automatically after using cooker to cool it down, seems to be active for ages and uses a fair bit of power.
We've discovered that turning the whole system.off and opening the door for 5 minutes, cures this without using the battery power.

Something within.our system uses 2 watts up continuously, and have yet to work this out.
Any suggestions?

2 Watts? you are a lucky chap! I have around 40W of constant background use

Best way to find it is to remove fuses and see what power draw goes away. It is just a process of trail and elimination.
Typical constant draws in a motorhome are:
USB Sockets - they can be powered and use something even when not in use;
TV on Standby? Bluetooth speaker on standby? - in the house, very common of course.
Fridge electronics - an AES fridge may be always on control-board wise
Monitoring - Monitoring power takes power (I think my power monitoring actually uses more power than some folk actually use day-to day!)

And the 2W itself may not even be real. Depending how/what you are using to see this 2W reported power, the device itself may need calibration? it is not unusual to have a phantom load that is not really there, just a monitor that needs resetting (but you need to physically remove all loads to check if this is the case - how you do that depends on the device. e.g. if a Victron BMV for example, you would disconnect the -ve cable from the shunt LOAD terminal)

 

[Nick-Mandy]

2 Watts? you are a lucky chap! I have around 40W of constant background use

Best way to find it is to remove fuses and see what power draw goes away. It is just a process of trail and elimination.
Typical constant draws in a motorhome are:
USB Sockets - they can be powered and use something even when not in use;
TV on Standby? Bluetooth speaker on standby? - in the house, very common of course.
Fridge electronics - an AES fridge may be always on control-board wise
Monitoring - Monitoring power takes power (I think my power monitoring actually uses more power than some folk actually use day-to day!)

And the 2W itself may not even be real. Depending how/what you are using to see this 2W reported power, the device itself may need calibration? it is not unusual to have a phantom load that is not really there, just a monitor that needs resetting (but you need to physically remove all loads to check if this is the case - how you do that depends on the device. e.g. if a Victron BMV for example, you would disconnect the -ve cable from the shunt LOAD terminal)

Thanks David.
I reckon I am lucky with only a 2 watt drawage when everything is off.
I think its the Victron BMV.
It won't be the USB points as there's no power getting to them.

Hope all this information helps other peeps on this forum.

 

[wildebus]

Thanks David.
I reckon I am lucky with only a 2 watt drawage when everything is off.
I think its the Victron BMV.
It won't be the USB points as there's no power getting to them.

Hope all this information helps other peeps on this forum.

If you are seeing 2W with the shunt load disconnected, I would definately do a calibration reset. 2W is a very small draw so not something to really get worried about anyway.

 

[trevskoda]

Thank heavens for good folk like david on here, hip hip horray.