E.H.U. continuous? Here's an interesting read. (1 Viewer)

[BouncyBoatFolk]

I saw this and found it interesting, and thought others might also.

Permanent connection to EHU in storage can be bad for a Habitation battery?

We think there is mounting evidence that using EHU in long term storage might not be the best choice. The Victron Energy Unlimited explains it all here.

www.aandncaravanservices.co.uk

It's a bit of long read, but worth staying with.
Mike

 

[Brains]

Interesting.

If I was to leave my M/H on EHU whilst in storage, I'd fit a £10 timeclock and limit charging to about 4hrs per week.

Also it shows that DIY solar installations using domestic panels are not recommended.

I have rigid solar panels and a Victron system installed by a reputable motorhome installation company (VanBitz) with a battery master so that the trickle charge goes to both batteries.

 

[poppycamper]

There seems to me two schools of thought on these type of subjects...
On one hand you get those who are happy to let technology look after their equipment...be it solar chargers not cooking batteries... temp probes preventing sub zero charging of lithiums or so called smart chargers which you can supposedly leave unattended.
Then you get the likes of me who don't trust technology and have physical means to disconnect solar and chargers etc by fitting switches to isolate each item.
Each to there own as the saying goes.!!!!

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[eddie]

We get dozens of enquiries every winter about flat batteries and the ensuing problems that "jump starting" has produced

We don't get problems because of being left on hook up or with solar panels, well not that I can remember for the last few years

My van is plugged in 24/7 and has nearly 500w of solar on the roof

 

[nicholsong]

I saw this and found it interesting, and thought others might also.

Permanent connection to EHU in storage can be bad for a Habitation battery?

We think there is mounting evidence that using EHU in long term storage might not be the best choice. The Victron Energy Unlimited explains it all here.

www.aandncaravanservices.co.uk

It's a bit of long read, but worth staying with.
Mike

In that article the author wrote that UK mains run at 240v and Continental ones at 220v. I thought it had all been standardised at 230v some time ago.

Am I right or wrong please?

Geoff

 

[David and Sally]

In that article the author wrote that UK mains run at 240v and Continental ones at 220v. I thought it had all been standardised at 230v some time ago.

Am I right or wrong please?

Geoff

Yes. Way back in 2003

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[Richard n Ann]

I don't use the van's on board 10amp smart charger at home, even though it's smart, actually it's not that smart, it could 'think' a faulty battery is flat and start shoving 10 amps into it like what happened in 2019 with the solar controller. The battery got hot and the Votronic controller eventually shut off when the temperature reached 50c or whatever it's set to do.

So now when at home and it's unattended I use the optimate 2, it's only capable of giving 0.8 amps so can never get the new battery hot. It will let me know with an LED if it's not happy.

Also it let's the battery rest every half hour and only floats at 13.5v so as to slow down the loss of electrolyte.
Here's a screenshot of it doing it's thing

 

[Richard n Ann]

In that article the author wrote that UK mains run at 240v and Continental ones at 220v. I thought it had all been standardised at 230v some time ago.

Am I right or wrong please?

Geoff

No our voltage system never changed, would have been too expensive. What they did was widen the accepted tolerance voltage to encompass both our and the EUs systems

 

[Jim]

That guy again. Bless him, He used to get a bee in his bonnet and spout off. I've read his stories about how inverters are just dangerous, Solar panels bad, Battery Masters should not be used on motorhomes.

If you read the Ctek manual, when they are on stage seven float they can be left long term unattended

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[Odd job]

I have EHU at home and switch off the on board charger and connect a battery conditioner with float charge and don't have a problem

 

[BouncyBoatFolk]

I was not unduly influenced by the article. I have my van EHU. hooked up through a time clock, giving it just a couple of hours at midnight when the economy 7 kicks in. I have a USB fan attached via a 240v socket, so there is some usage[ minimal] but a some. I had a look for USB timers, but came up short of something usable, and that would also mean leaving the 12v switched on. I can monitor the the starter battery current status through the radios display.
Mike

 

[Raul]

It has some truth in it. A prolonged storage float of 13,8v is bad. Every battery manufacturer will recommend a float of 2,2vpc 13,2v for storage, 13,6v for intermittent partial cycling and 13,8v for EVREY DAY cycling. So if you are not cycling every day and your float is at 13,8v expect corrosion.
There will be replies, like: I had no problems. You don’t know unless you open the case an look at the plates. Yes will give you consistent higher voltage, but that’s not healthy. High voltage means high acid density, means loss of electrolyte due to prolonged unnecessary gassing. The battery starts life with a mix acid and water. The acid never leaves the battery, the water does every time it gasses. So if you can’t top up the water, limit the gassing time and voltage. As it looses its water, the concentration of acid increases, so the corrosion and voltage. Generally a healthy battery with a mix of 1,280 electrolyte, fully charged and rested will show 12,7v. Any slight deviation is the quantity of water acid ratio.

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[Lenny HB]

A lot depends on the equipment in use & the type of batteries. Nowadays Elektroblocks hold the absorption phase for 16 hours on the Gel setting so each time you switch it on it will go to the bulk charge stage and if the battery is charged it will switch to absorption phase for 16 hours so if you have Gel batteries probably better left on permantly as a 13.8v float won't harm Gels.

I let my solar panels & a Votronic regulator takes care of my batteries don't bother with hook up when then the van is sitting at home. Decent regulators like the Votronic or Victron don't cause any problems.

 

[Googlebot]

I was reading his section on lithium batteries, he really doesn’t seem to rate them and instead advocates deep discharge lead acid.

I turned it off, I don’t need that kind of negativity after buying lithium.

 

[nicholsong]

No our voltage system never changed, would have been too expensive. What they did was widen the accepted tolerance voltage to encompass both our and the EUs systems

OK thanks. Well if that is the case even the article said that if on 220v, as we are then in Poland, there should be no problem with leaving the MH on EHU for months, as I have done every winter and the batteries are fine after 5 years and hardly need topping up. So all good.

Geoff

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[Raul]

A lot depends on the equipment in use & the type of batteries. Nowadays Elektroblocks hold the absorption phase for 16 hours on the Gel setting so each time you switch it on it will go to the bulk charge stage and if the battery is charged it will switch to absorption phase for 16 hours so if you have Gel batteries probably better left on permantly as a 13.8v float won't harm Gels.

I let my solar panels & a Votronic regulator takes care of my batteries don't bother with hook up when then the van is sitting at home. Decent regulators like the Votronic or Victron don't cause any problems.

I could not agree more about the equipment and different battery construction. But, absorption it’s not a timed event. This is a old rudimentary work around method to try to get a battery to full. The new smart chargers have adaptive algorithms that calculate the necessary time. The time is holy dependant on: rate of charge and depth of discharge. Every time the charger wakes up, measures the voltage and estimated the SOC, then based on the charge rate it times the absorb.
Imagine you take out 20ah of a 300ah then the electroblock slaming in 16hrs absorb. And on a different day you take out 150ah and still a 16hrs absorb. Does that sound right to you? Victron chargers have a nice adaptive algorithm that once selected, it will time the absorb depending on SOC. As a charger only, it’s not perfect, but miles better than fixed absorb. When integrated into a system where it has a bmv, ve bus comms, it’s almost spot on accurate.

 

[two]

In the case of Lithium, I believe the common advice for storage is to keep them between 50% and 75% SoC. How is that achieved?

 

[Lenny HB]

In the case of Lithium, I believe the common advice for storage is to keep them between 50% and 75% SoC. How is that achieved?

They have very low self discharge rates and can be left for months without charging, so charge/discharge to 75% leave & forget.

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[two]

Yes, but:
How do you not exceed the 75%?
I'd expect an "intelligent" charger to stop at 75% without manual interference.

 

[autorouter]

n that article the author wrote that UK mains run at 240v and Continental ones at 220v. I thought it had all been standardised at 230v some time ago.

Am I right or wrong please?

Yes and no. They changed the limits on the 230V spec so it was + or - 10%. So, as if by magic, a 240V supply was actually "230V, or within 10% of it", so everyone was happy.

 

[autorouter]

I could not agree more about the equipment and different battery construction. But, absorption it’s not a timed event. This is a old rudimentary work around method to try to get a battery to full. The new smart chargers have adaptive algorithms that calculate the necessary time. The time is holy dependant on: rate of charge and depth of discharge. Every time the charger wakes up, measures the voltage and estimated the SOC, then based on the charge rate it times the absorb.
Imagine you take out 20ah of a 300ah then the electroblock slaming in 16hrs absorb. And on a different day you take out 150ah and still a 16hrs absorb. Does that sound right to you? Victron chargers have a nice adaptive algorithm that once selected, it will time the absorb depending on SOC. As a charger only, it’s not perfect, but miles better than fixed absorb. When integrated into a system where it has a bmv, ve bus comms, it’s almost spot on accurate.

Another example: with the Sterling B2B you set the 'Absorption Time Factor'. The B2B measures the time taken to reach the absorption voltage. Then it multiplies that time by the Absorption Time Factor. The result is used to time the absorption stage. So if the battery is already nearly charged, the time to absorption voltage is short, and so is the calculated absorption time. Different battery types require different ATFs.

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[Wizz]

Anyone know if there is such a thing as an EHU lead timer socket, (not sure if one exists, or is even possible). I only ask as I have an outside EHU socket attached to my garage wall from which I plug my MH in to. It would be handy if I could put in on a timer for future occasions when I'm not around, when we are allowed out again..........

 

[Raul]

Yes, but:
How do you not exceed the 75%?
I'd expect an "intelligent" charger to stop at 75% without manual interference.

You can’t. Because the voltage curve is so flat you could have a state of charge of 30% to 90% approx. @ 13,2v. What you can do is lower the absorb time to 1min and absorb voltage 13,6v. This will get you close to 90% soc and have some small loads. Like a camera alarm battery master etc. Other way round, if it will be stored disconnected, charge to full and take out 25%. Then disconnect and store it up to a year.
At the moment what I do with mine, is make use of the cold weather. Raise the temp cut of at 4-5 deg to stop it charging. The loads can bleed 20ah daily, and I managed to keep it at 80% for few weeks now. If i have to drive, I disable the B2B by a remote switch.

 

[Lenny HB]

Yes, but:
How do you not exceed the 75%?
I'd expect an "intelligent" charger to stop at 75% without manual interference.

Either turn the charger off before it's fully charged or if it is at 100% discharge it down to 75% before storing, its not hard to do.

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[donkey]

Hi Wizz

There are loads of external sockets with combined timers, here is one example: https://www.wickes.co.uk/Masterplug...Vj-3tCh2faQXcEAQYBCABEgKrmvD_BwE&gclsrc=aw.ds

 

[Wizz]

Hi Wizz

There are loads of external sockets with combined timers, here is one example: https://www.wickes.co.uk/Masterplug...Vj-3tCh2faQXcEAQYBCABEgKrmvD_BwE&gclsrc=aw.ds

Hi Donkey, thanks for this. But I'm actually thinking of something I can add to my existing set-up. In essence, a timer


specifically for EHU

 

[donkey]

You could fit one inside, in the supply to your external socket, that way it doesn't need to be weather proof.
Geoff

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[BouncyBoatFolk]

Anyone know if there is such a thing as an EHU lead timer socket, (not sure if one exists, or is even possible). I only ask as I have an outside EHU socket attached to my garage wall from which I plug my MH in to. It would be handy if I could put in on a timer for future occasions when I'm not around, when we are allowed out again..........

You can plug your EHU hook up lead in via a plug in 7 day 24h timer, that gives you the freedom of days per week and hours per day. If you're taking some reserve of the battery through ongoing attachments, alarms, trackers ect, a couple of nights without charging would leave some capacity for refilling.
Mike.

 

[Richard n Ann]

The problem with a timer is you are shallow cycling the battery. A battery only has so many cycles before it reaches the end of it's life. Use a low power maintainer.

 

[kevenh]

No our voltage system never changed, would have been too expensive. What they did was widen the accepted tolerance voltage to encompass both our and the EUs systems

OK thanks. Well if that is the case even the article said that if on 220v, as we are then in Poland, there should be no problem with leaving the MH on EHU for months, as I have done every winter and the batteries are fine after 5 years and hardly need topping up. So all good.

Geoff

Yes and no. They changed the limits on the 230V spec so it was + or - 10%. So, as if by magic, a 240V supply was actually "230V, or within 10% of it", so everyone was happy.

I was taught It’s an off set tolerance, +10/-6
Still described like that here

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