Lithium Batteries and EHU- still confused

[Ingwe]

We are due to have lithium batteries fitted next week. The reason we made the decision to have them is because we have only one leisure battery and spend a fair proportion of our travelling time on aires where there is no hook up. The van has a 120 watt solar panel. Whilst researching the matter, I came upon a post by Eddie at Van Bitz in relation to charging lithium batteries in which he seemed to say that if you mostly use hook up, you don’t need lithium batteries.

I understand that but what about those of us who sometimes use hook up in order to use the 240v gear on the van (micro-wave, water heating, ebike battery chargers etc) as well as spending a considerable proportion of time where there is no EHU? If say, like last winter, we stay on a Spanish site for 6-8 weeks where EHU is available and we have two lithium batteries fitted, can we safely use the EHU without damaging the batteries? What would be the best thing to do in such circumstances?

If I‘ve misunderstood Eddie’s comment (I can’t immediately locate the specific post) I apologise. The fitting of the lithium batteries is imminent but I’m still a bit confused on what to do in the above circumstances.

 

[pappajohn]

Ideally you need a charger with lithium setting, a regular charger won't provide enough volts to FULLY charge a lithium battery.

What Eddie means is, if on hookup you don't need lithium ...the hookup provides power to the 12v system with the battery smoothing the voltage.
Depending on your charger you don't even need a battery on hookup.

 

[cmcardle75]

We are due to have lithium batteries fitted next week. The reason we made the decision to have them is because we have only one leisure battery and spend a fair proportion of our travelling time on aires where there is no hook up. The van has a 120 watt solar panel. Whilst researching the matter, I came upon a post by Eddie at Van Bitz in relation to charging lithium batteries in which he seemed to say that if you mostly use hook up, you don’t need lithium batteries.

I understand that but what about those of us who sometimes use hook up in order to use the 240v gear on the van (micro-wave, water heating, ebike battery chargers etc) as well as spending a considerable proportion of time where there is no EHU? If say, like last winter, we stay on a Spanish site for 6-8 weeks where EHU is available and we have two lithium batteries fitted, can we safely use the EHU without damaging the batteries? What would be the best thing to do in such circumstances?

If I‘ve misunderstood Eddie’s comment (I can’t immediately locate the specific post) I apologise. The fitting of the lithium batteries is imminent but I’m still a bit confused on what to do in the above circumstances.

Lithium work fine with EHU. It's just that they're expensive and if you're on EHU all the time, it's a bit profligate to have expensive batteries that you don't need. That said, make sure your mains charger had a good lithium profile so you don't damage them.

Also, if you're going to be on EHU for a while, try to get the lithium batteries well below 80% and disconnect them. That'll make them last longer. Sitting at 100% all the time wears them out quicker. Best to only charge to 100% whenever you're going off-grid, or once a month to recalibrate any battery monitors.

 

[Ingwe]

Also, if you're going to be on EHU for a while, try to get the lithium batteries well below 80% and disconnect them.

Is there a simple way to disconnect them? Can one just turn off the newly fitted mains charger that has a lithium profile?

 

[Ingwe]

Ideally you need a charger with lithium setting, a regular charger won't provide enough volts to FULLY charge a lithium battery.

What Eddie means is, if on hookup you don't need lithium ...the hookup provides power to the 12v system with the battery smoothing the voltage.
Depending on your charger you don't even need a battery on hookup.

The battery suppliers are fitting a new mains charger that has a lithium profile.

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[cmcardle75]

Is there a simple way to disconnect them? Can one just turn off the newly fitted mains charger that has a lithium profile?

The important thing is that the charger can run in PSU mode. A modern charger with Lithium profile is likely to support this, but you do need to check. (i.e. Victron Bluesmart is absolutely fine). As for disconnecting the battery, you'd have to be lucky for this faciltity to be built in. I use a quick disconnect negative terminal on the battery itself so I can isolate it.

 

[Just smiffy]

I think what eddievanbitz was saying is that if you go to the expense of having lithiums then make sure you have a suitable charging system to put the power back in that you have taken out.. ie: solar, b2b and suitable alternator along with the mains charger being able to charge lithiums properly…

If these things are done and you move around a fair bit you shouldn’t have to use EHU, however there are times when you don't move for some time and there may be little sun then you need to make sure your mains charger is up to it..

 

[Armytwowheels]

try to get the lithium batteries well below 80% and disconnect them

How does that work then? How about all your 12v dependent stuff - fridge, lights water pump, heater etc.

 

[royandsharont]

It’s like the 2021 Adria Twin models have a charging system that does not include lithium, I believe, but the new 2022 models which should be arriving anytime now should have as lithium batteries are now an option to the AGM ones

I found a link to THIS website in a thread on here that helped me understand it better, it’s all about the charging

 

[cmcardle75]

How does that work then? How about all your 12v dependent stuff - fridge, lights water pump, heater etc.

This is when on EHU. Modern chargers are capable of providing a stable 12V even when the battery is disconnected. Indeed, you need this capability for any Lithium battery setup, as the BMS will often disconnect the battery automatically if it detects overvoltage on one of the cells, which is quite likely when approaching 100% without perfect cell balance.

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[Steve and Denise]

I fitted my own lithium and simply fitted a switch on the 220v supply to the Victron charger or as said alternatively fit a battery isolator and use psu setting on charger

 

[Guyadria]

It’s like the 2021 Adria Twin models have a charging system that does not include lithium, I believe, but the new 2022 models which should be arriving anytime now should have as lithium batteries are now an option to the AGM ones

It will be interesting to see what is different. Only the Schaudt Electroblock component on 2021 model does not have a Lithium selectable switch. I wonder if they will change this or add a new charging component a la Victron Smart charge.

 

[Armytwowheels]

This is when on EHU. Modern chargers are capable of providing a stable 12V even when the battery is disconnected. Indeed, you need this capability for any Lithium battery setup, as the BMS will often disconnect the battery automatically if it detects overvoltage on one of the cells, which is quite likely when approaching 100% without perfect cell balance.

Ok, everyday is a school day!

It seems a bit of a faff to have to disconnect the batteries when on EHU, and how about the solar, would they not have to be disconnected too and in what order?

 

[cmcardle75]

Ok, everyday is a school day!

It seems a bit of a faff to have to disconnect the batteries when on EHU, and how about the solar, would they not have to be disconnected too and in what order?

You don't have to. It's just that the batteries will last longer. Even if you don't, they'll still last many times the life of a lead acid.

Disconnecting solar would be a faff if you're using the van, as you need a battery to provide the peak loads, so I wouldn't bother. However, if storing, it would be better to isolate the battery than to leave it connected with the solar. Solar should be redirected to the engine battery instead.

 

[Armytwowheels]

Thanks, I get it, sort of. We use our van 24/7 and have the Victron Blue Smart charger. However, we have spent most of the summer on EHU so this thread caused a bit of concern. During the height of the summer we were and still are, using the fridge on AES in order to work the batteries

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[Steve and Denise]

I just switch the charger off so still have ehu to use heating, fridge, and other 220v appliances and use the batteries for 12v easy to monitor through the battery app the solar keeps the battery where it needs to be.

 

[Ingwe]

The important thing is that the charger can run in PSU mode. A modern charger with Lithium profile is likely to support this, but you do need to check. (i.e. Victron Bluesmart is absolutely fine). As for disconnecting the battery, you'd have to be lucky for this faciltity to be built in. I use a quick disconnect negative terminal on the battery itself so I can isolate it.

The proposed updated mains charger is the Victron ip22 20 amp charger. Will this run in PSU mode?

 

[Steve and Denise]

The proposed updated mains charger is the Victron ip22 20 amp charger. Will this run in PSU mode?

If you are paying a company to do this fitting they should explain all of this to you, that’s why you pay them

 

[Pausim]

I have lithium and don’t lose any sleep about using an EHU without a lithium profile mains charger. The 14.4V gel setting very slightly undercharges it but who cares, when on an EHU who needs a full battery. Unlike lead acid batteries (particularly agm) undercharging lithium does not harm them. The gel profile maintains a longer absorption phase than a lithium battery needs but when full it just stops taking a charge. The charger drops back to a float/maintenance charge of 13.8V after a few hours, which is the same level as used in lithium chargers. Basically the only significant difference I can find between a gel profile and a lithium one is the absorption phase which is not worrying me. If it did worry me I would fit my spare Sterling charger which has a lithium profile but I don’t consider it worth the disruption to the original electrics.

What does matter is having a full battery when arriving somewhere without an EHU and my B2B takes care of this.

 

[St3v3]

seemed to say that if you mostly use hook up, you don’t need lithium batteries.

......................

I understand that but what about those of us who sometimes use hook up

You've answered your own question lol.

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[cmcardle75]

The proposed updated mains charger is the Victron ip22 20 amp charger. Will this run in PSU mode?

I have exactly this charger (Bluesmart version, but I think the non-Bluetooth version is basically the same). It works perfectly in this scenario. The lights didn't even flicker when the BMS cut out as one of the cells had filled up before the others.

 

[Howard B]

The guys at KS Energy have told me i can use the gel setting with their Lithium batteries. Just debating if i can justify spending £800.

 

[Ingwe]