Insulate leisure battery

[Duncan2580]

Thanks for that

 

[headlight]

So you were using gas heating and the 12v blower fan.
If your 90AH leisure battery was fully charged you have 45amps usable power.
The blower fan, even if on full overnight, would still not drain your battery to 13%.
If your battery really was drained to 13% SOC then you will have harmed it and reduced its capacity as lead acid batteries shouldn't be drained below 50%.

 

[Duncan2580]

Yes I have been told that but was surprised it was 88%when I got home. I did check it twice.
Are we saying then the battery is ok when it’s - degrees in a galvanised compartment in the flooring,
Thanks

 

[headlight]

Yes I have been told that but was surprised it was 88%when I got home. I did check it twice.
Are we saying then the battery is ok when it’s - degrees in a galvanised compartment in the flooring,
Thanks

Yes.
We just don't get cold enough temps to seriously affect a lead acid battery.
How do you think vehicle starter batteries cope in the winter.
If the battery is in good condition it will cope fine.

 

[Duncan2580]

Yes.
We just don't get cold enough temps to seriously affect a lead acid battery.
How do you think vehicle starter batteries cope in the winter.
If the battery is in good condition it will cope fine.

Ok thanks

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[two]

(I've not tried this but) I believe that letting a battery freeze is likely to kill it.
To avoid freezing, keep it as fully charged as possible.
It's fine to insulate them from the cold. They perform better when warmer.

 

[Duncan2580]

Is it lead acid.
cold wont affect it that much unless it gets to severe -10s and such.
If it was -4 you can expect 5-10% affected, but remember its probably not -4 in the battery compartment.

had your van charged the battery on the way home via b2b or alternator

And remember if you are checking under load it will show a lot less than after its settled with no load.

was the battery from a reputable dealer and had a good full charge

It’s not connected to the alternator just the solar panels (300)
Yes I got it from the company who did work on my motorhome

 

[Duncan2580]

(I've not tried this but) I believe that letting a battery freeze is likely to kill it.
To avoid freezing, keep it as fully charged as possible.
It's fine to insulate them from the cold. They perform better when warmer.

Thanks any thoughts on reputable insulation. There’s not much room

 

[headlight]

Ok thanks

Also bear in mind that your 300 watts of solar will produce very little this time of year.
Enough to keep your battery topped up but not enough to replace any serious use.

 

[Duncan2580]

Probably not as sophisticated as the victron but I like my NASA BM1

View attachment 840437

The scale on the right, does that tell you how much the battery is charged.

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[headlight]

Thanks any thoughts on reputable insulation. There’s not much room

All insulation will do is slow down how quickly the battery will cool to ambient temperatures.
If it is minus 4c the battery will still fall to that temp, it will just take longer.
Minus 4c is not cold enough to have much of an effect on a good battery.
I expect your van started OK and your starter battery will have been at least as cold as your leisure battery.

 

[Richard n Ann]

The scale on the right, does that tell you how much the battery is charged.

Yes there are other screens you can select though, you can display charge as %. Also time to discharged, time to charged (if charging) also as mentioned starter battery voltage

 

[Pausim]

Not all batteries are the same but I think the effect of cold weather may be being significantly underestimated. Battery capacity is measured at 25˚C and with flooded lead acid batteries the capacity is already compromised well before dropping below freezing. From this article

Temperature vs. Capacity - Flooded Lead-Acid Batteries

Battery capacity is affected by ambient temperature. Capacity is maintained in warmer temperatures, but cycle life is reduced. Cooler ambient temperatures will reduce battery capacity, but cycle life is improved. Note: Cycle life ...

support.rollsbattery.com

I lifted this graph.

 

[Tombola]

It’s not connected to the alternator just the solar panels (300)
Yes I got it from the company who did work on my motorhome

was only wondering if the battery had got a charge on the way home thats all.
you can as good as forget the solar this time of year

 

[Duncan2580]

Thanks

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[headlight]

Not all batteries are the same but I think the effect of cold weather may be being significantly underestimated. Battery capacity is measured at 25˚C and with flooded lead acid batteries the capacity is already compromised well before dropping below freezing. From this article

Temperature vs. Capacity - Flooded Lead-Acid Batteries

Battery capacity is affected by ambient temperature. Capacity is maintained in warmer temperatures, but cycle life is reduced. Cooler ambient temperatures will reduce battery capacity, but cycle life is improved. Note: Cycle life ...

support.rollsbattery.com

I lifted this graph.
View attachment 840480

At minus 5c the battery is still almost 75% .
I think the OP's battery has been compromised and also he has no engine charging just solar, which at this time of year won't do much, certainly not enough to replace any serious usage.
He said the battery was at 88% when he got home, if its just parked up partially discharged it will cause sulfation which will reduce the battery capacity.

 

[autorouter]

It’s not connected to the alternator just the solar panels (300)

Are you sure? That would be most unusual. Every motorhome I've ever seen has a method of charging the leisure battery from the alternator while the engine is running. If you've driven 200 miles that would account for it being up to 88% from 13%. For example there is often a relay, triggered by the alternator, that connects the leisure battery to the starter battery when the engine is running, so that the alternator can charge them both. When the engine stops, the relay disconnects them. It's called a split charge relay.

You can easily check this. When not being charged, a lead-acid battery voltage is between about 12.0V and 12.8V. When being charged, its voltage is forced up to over 13V, probably around 14.5V when being actively charged. So measure the battery voltage with the engine stopped, then turn the engine on and see if it goes up. Best to do this when it's dark to avoid the solar confusing matters.

 

[Duncan2580]

Are you sure? That would be most unusual. Every motorhome I've ever seen has a method of charging the leisure battery from the alternator while the engine is running. If you've driven 200 miles that would account for it being up to 88% from 13%. For example there is often a relay, triggered by the alternator, that connects the leisure battery to the starter battery when the engine is running, so that the alternator can charge them both. When the engine stops, the relay disconnects them. It's called a split charge relay.

You can easily check this. When not being charged, a lead-acid battery voltage is between about 12.0V and 12.8V. When being charged, its voltage is forced up to over 13V, probably around 14.5V when being actively charged. So measure the battery voltage with the engine stopped, then turn the engine on and see if it goes up. Best to do this when it's dark to avoid the solar confusing matters.

Thanks for all the information.
When I bought the motorhome earlier this year I had the solar panels fitted, they told me I needed a new battery which I did but it wasn’t holding the charge, even when not using the motorhome. I ended up buying another battery and the same thing happened again. I then took the motorhome back to the company who fitted the solar panels and they found out the leisure battery was charging the engine battery eventually .
They disconnected that and told me it will just charge the leisure battery via solar panels. They were bemused as why it was wired up that way.
I will check what you have said, thank

 

[headlight]

Thanks for all the information.
When I bought the motorhome earlier this year I had the solar panels fitted, they told me I needed a new battery which I did but it wasn’t holding the charge, even when not using the motorhome. I ended up buying another battery and the same thing happened again. I then took the motorhome back to the company who fitted the solar panels and they found out the leisure battery was charging the engine battery eventually .
They disconnected that and told me it will just charge the leisure battery via solar panels. They were bemused as why it was wired up that way.
I will check what you have said, thank

For the leisure battery to charge the starter battery it sounds like the split charge relay has failed.
A new relay will sort that out as solar in UK winter is pretty useless.

 

[Duncan2580]

Thanks for all the information.
When I bought the motorhome earlier this year I had the solar panels fitted, they told me I needed a new battery which I did but it wasn’t holding the charge, even when not using the motorhome. I ended up buying another battery and the same thing happened again. I then took the motorhome back to the company who fitted the solar panels and they found out the leisure battery was charging the engine battery eventually .
They disconnected that and told me it will just charge the leisure battery via solar panels. They were bemused as why it was wired up that way.
I will check what you have said, thank

Do I do this with some sort of meter or get a battery meter fitted which has been mentioned in this thread

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[autorouter]

When I bought the motorhome earlier this year I had the solar panels fitted, they told me I needed a new battery which I did but it wasn’t holding the charge, even when not using the motorhome. I ended up buying another battery and the same thing happened again. I then took the motorhome back to the company who fitted the solar panels and they found out the leisure battery was charging the engine battery eventually .
They disconnected that and told me it will just charge the leisure battery via solar panels. They were bemused as why it was wired up that way.

Does your motorhome have a smart alternator? Newer motorhomes usually have them. A smart alternator keeps the starter battery only partially charged, by stopping charging except when decelerating or braking. It's OK for a starter battery, but no good for a leisure battery. To charge a leisure battery from a smart alternator, you need a device called a DC-DC charger, also called a Battery-to battery (B2B) charger.

Some motorhomes with smart alternators weren't fitted with a B2B at first, but I think all the later ones have a B2B.

You can get B2Bs of about 20 to 30A, similar to what a standard alternator would supply. Or you can get a bigger one, say 60A, up to 140A if your alternator will take it. Many motorhomes have uprated alternators of up to 200A.

 

[headlight]

Does your motorhome have a smart alternator? Newer motorhomes usually have them. A smart alternator keeps the starter battery only partially charged, by stopping charging except when decelerating or braking. It's OK for a starter battery, but no good for a leisure battery. To charge a leisure battery from a smart alternator, you need a device called a DC-DC charger, also called a Battery-to battery (B2B) charger.

Some motorhomes with smart alternators weren't fitted with a B2B at first, but I think all the later ones have a B2B.

You can get B2Bs of about 20 to 30A, similar to what a standard alternator would supply. Or you can get a bigger one, say 60A, up to 140A if your alternator will take it. Many motorhomes have uprated alternators of up to 200A.

The OP's van is 1999.

 

[headlight]

Does your motorhome have a smart alternator? Newer motorhomes usually have them. A smart alternator keeps the starter battery only partially charged, by stopping charging except when decelerating or braking. It's OK for a starter battery, but no good for a leisure battery. To charge a leisure battery from a smart alternator, you need a device called a DC-DC charger, also called a Battery-to battery (B2B) charger.

Some motorhomes with smart alternators weren't fitted with a B2B at first, but I think all the later ones have a B2B.

You can get B2Bs of about 20 to 30A, similar to what a standard alternator would supply. Or you can get a bigger one, say 60A, up to 140A if your alternator will take it. Many motorhomes have uprated alternators of up to 200A.

The OP's van is 1999 so no smart alternator or B2B, it will have a simple split charge.

 

[Tombola]

OP, you have 2 choices really here
find and fix the alternator charging via a split charge relay. WHich basically just connect a relay when the ignition is on so both batteries are charged from your alternator (cheapest way) but could be a bit of a pain as someone else has disconnected"something" to stop the drain on your leisure battery to the vehicle battery

OR you fit a b2b something like below you can do that direct to the vehicle battery and lesiure battery terminals yourself and is easy enough.

Victron Orion-Tr Smart 12V 18A Isolated DC-DC B2B Split Charge Kit

Victron Orion 12V 18A Smart Isolated DC-DC B2B Split Charge Kit. These Battery to Battery (B2B) charging kits are designed to charge your vehicle's leisure battery whilst driving and are appropriate for vehicles with Smart alternators, usually Euro 5 / Euro 6 compliant alternators. This Kit...

vanjunkies.co.uk

there are higher amp more expensive ones depending on your usage.

.If you spent your time in southern spain the solar would sort you out.
and of course, if you spent time on sites with EHU then that can help you survive the odd day after charging on EHU