T6 California Beach leisure battery capacity?

mtnsmtnsmtnsmtns · Feb 16, 2023

Hi all, apologies if this is a very obvious question, but I have a T6 Cali Beach and was wondering about the capacity of the leisure battery.

We're planning to take the van to a festival this summer, and there is no option for EHU, so I'm wondering how far the leisure battery will get us. I've been looking at Jackery's but not sure how I would compare the capacity of, say a Jackery 1000 with the leisure battery. I've managed to take a photo of the top of the battery, giving me it's headline specification, and I found a website (https://www.convert-formula.com/ah-wh/) which if I plug in 75Ah and 12v into it, suggests the leisure battery should do 900Wh, but I find that hard to believe as a Jackery 1000 is about £1000, and the leisure battery can be replaced for about £100!

I mean, if that is correct, and the leisure battery is the equilivant of 900Wh, we should be good for a family to keep phones charged for a long weekend, and run some lights, but it seems too good to be true (and saves me a big pile of cash)!

WelshGas · Feb 16, 2023

mtnsmtnsmtnsmtns said:
Hi all, apologies if this is a very obvious question, but I have a T6 Cali Beach and was wondering about the capacity of the leisure battery.

We're planning to take the van to a festival this summer, and there is no option for EHU, so I'm wondering how far the leisure battery will get us. I've been looking at Jackery's but not sure how I would compare the capacity of, say a Jackery 1000 with the leisure battery. I've managed to take a photo of the top of the battery, giving me it's headline specification, and I found a website (https://www.convert-formula.com/ah-wh/) which if I plug in 75Ah and 12v into it, suggests the leisure battery should do 900Wh, but I find that hard to believe as a Jackery 1000 is about £1000, and the leisure battery can be replaced for about £100!

I mean, if that is correct, and the leisure battery is the equilivant of 900Wh, we should be good for a family to keep phones charged for a long weekend, and run some lights, but it seems too good to be true (and saves me a big pile of cash)!

That calculation is correct but you can only use half of it 450 watts without damaging the battery.
AGM batteries, your Leisure Battery, should only be run down to 50% capacity to avoid longtem damage.

Amarillo · Feb 16, 2023

I think two nights of phone charging, lights and a small fridge will be fine with the Beach battery. Three nights if you cut out the fridge.

Install 200 watts of solar panels on the roof and you can double your time off grid in winter and/or cloudy conditions and indefinitely in good weather conditions.

andyinluton · Feb 16, 2023

mtnsmtnsmtnsmtns said:
I mean, if that is correct, and the leisure battery is the equilivant of 900Wh, we should be good for a family to keep phones charged for a long weekend, and run some lights, but it seems too good to be true (and saves me a big pile of cash)!

How often are you going to need it?
You can get a Halfords car Jump start pack that you can charge phones & run a 12v light from for £60. Seems a bit overkill to spend £1000 on a jackory for a one off.

yossarian · Feb 16, 2023

Running your engine for 60 minutes will cost probably less than a pound and add about ~~360 - 480~~ 240-360Wh. Zero capital outlay.

[Edit: single battery charging is a little slower]

Lee.Van.Cleef · Feb 16, 2023

Jackery has options of solar panels at about £200 which can be daisy chained to top up tge power pack if that helps. The panels also have a USB c socket to direct charge phones etc.

mtnsmtnsmtnsmtns · Feb 17, 2023

WelshGas said:
That calculation is correct but you can only use half of it 450 watts without damaging the battery.
AGM batteries, your Leisure Battery, should only be run down to 50% capacity to avoid longtem damage.

Ok thanks, that's good to know. So will the battery cut off when it needs to? Or else how will I know when to stop using it when it gets to 50%, like you said?

da_murphster · Feb 17, 2023

Second battery under the drivers seat wired in parallel would be your cheapest option? Prolly about £200 all in once you have bought a matching battery and wired it up.

I'm going to look at solar (£4-500ish) but mainly as I'm considering sticking a subwoofer under the drivers seat.

The standard Beach battery could also be increased - I've got a 110ah battery in the same location in my old caravelle - the beach one is 90ah I think?

My experience is that I can do 3 days running a compressor fridge and lights on 110ah. I have several battery packs for phone charging.

yossarian · Feb 17, 2023

mtnsmtnsmtnsmtns said:
Ok thanks, that's good to know. So will the battery cut off when it needs to? Or else how will I know when to stop using it when it gets to 50%, like you said?

You can treat 12V at low or zero load as the minimum voltage you want to see. The voltage is visible on your control panel. The T6 state of charge indicator is generally regarded as useless.

02-Loaded-Battery-Voltage-vs.-SOC-AGM.jpg

mtnsmtnsmtnsmtns · Feb 17, 2023

yossarian said:
You can treat 12V at low or zero load as the minimum voltage you want to see. The voltage is visible on your control panel. The T6 state of charge indicator is generally regarded as useless.

No control panel on my 2016 T6 beach

"You can treat 12V at low or zero load as the minimum voltage you want to see." I'm really sorry but I'm not sure what this means?!

yossarian · Feb 17, 2023

mtnsmtnsmtnsmtns said:
No control panel on my 2016 T6 beach

"You can treat 12V at low or zero load as the minimum voltage you want to see." I'm really sorry but I'm not sure what this means?!

Ah sorry I hadn't realised.

You need some way to measure the voltage. Common ways are a plug in indicator (Amazon), a BM2 (Amazon) or just take your multimeter from home.

I use a BM2 on my starter battery. And I have a multimeter in my van.

mtnsmtnsmtnsmtns · Feb 17, 2023

No apology needed, I appreciate you taking the time to help me out.

Ok in context I think I get it, so I need to proactively monitor the voltage on the battery with one of the devices you've mentioned, and when it reads 12.0V with nothing running, it's time to stop using it?

I do have one of the cigarette lighter chargers with the voltage on, and it's reading 12.9V at the moment under no load (and jumped to 13.6V with the EHU connected). Is that good/normal? I bought the van second hand, so I have no idea how the battery has been previously used. Is there a way of determining the health of the battery from these readings?

Is this not a bit strange that a more casual user who hasn't looked into this, could damage the leisure battery, simply by using it (until it's empty).

WelshGas · Feb 17, 2023

mtnsmtnsmtnsmtns said:
No apology needed, I appreciate you taking the time to help me out.

Ok in context I think I get it, so I need to proactively monitor the voltage on the battery with one of the devices you've mentioned, and when it reads 12.0V with nothing running, it's time to stop using it?

I do have one of the cigarette lighter chargers with the voltage on, and it's reading 12.9V at the moment under no load (and jumped to 13.6V with the EHU connected). Is that good/normal? I bought the van second hand, so I have no idea how the battery has been previously used. Is there a way of determining the health of the battery from these readings?

Is this not a bit strange that a more casual user who hasn't looked into this, could damage the leisure battery, simply by using it (until it's empty).

The voltages shown are fine.
And to your last question YES.

If you have a factory fitted Parking Heater then that will switch Off if the voltage drops to 11.5v during use. Otherwise, on the Beach T6, you have to monitor the voltage with a bought 12v plug in Voltmeter to avoid running battery too low.

andyinluton · Feb 17, 2023

mtnsmtnsmtnsmtns said:
No apology needed, I appreciate you taking the time to help me out.

Ok in context I think I get it, so I need to proactively monitor the voltage on the battery with one of the devices you've mentioned, and when it reads 12.0V with nothing running, it's time to stop using it?

I do have one of the cigarette lighter chargers with the voltage on, and it's reading 12.9V at the moment under no load (and jumped to 13.6V with the EHU connected). Is that good/normal? I bought the van second hand, so I have no idea how the battery has been previously used. Is there a way of determining the health of the battery from these readings?

Is this not a bit strange that a more casual user who hasn't looked into this, could damage the leisure battery, simply by using it (until it's empty).

Don't panic - it's no different to flattening your car starter battery, not particularly good for it but not the end of the world. The important thing is to charge it as soon as possible & not leave it sitting there flat.

Someone recently did some experimenting trying to kill a battery by continually flattening it, he found - that the total amount of amp hours you got out of the battery was within 10% of being constant, irrespective of how low it was discharged.

What he was showing was that you could say charge from 50% up to 100% a 1000 times
or from 0% up to 100% 450 times, the decrease in the number of charges looks massive but actually its only a 10% drop in the amount of use you've had out of the battery as you've used it twice as long for each charge.

yossarian · Feb 17, 2023

mtnsmtnsmtnsmtns said:
need to proactively monitor the voltage on the battery with one of the devices you've mentioned, and when it reads 12.0V with nothing running, it's time to stop using it?

Exactly. And as Andy has said treat the voltage as a guide. AGM batteries are a bit tougher than old flooded batteries.

Recharging on EHU is usually better than alternator as EHU will observe a constant current, constant voltage profile while usually an alternator is a little primitive.