A solar and lithium question

[RonnieA]

When I specced my Hymer ML-T I intended to use it all year round and so the question of what would be required for a winter lay-up never entered my mind however, circumstances this year mean that I will probably have to park it up in it's storage site for several weeks at least, if not 2-3 months and I need some advice as to how best to protect my leisure and starter batteries over this lay-up. My set up is a 200w solar panel, a Schaudt LRM 1218 solar regulator, a Schaudt EBL30 and Hymer's Smart Battery system which consists of lithium and gel leisure batteries. The lithium battery is equipped with a protective function against overload. I'm aware that lithium batteries don't like to be constantly charged but at the same time I do want the solar to trickle charge the starter battery. I don't have a schematic of the system but my understanding is that the solar regulator will start to charge the starter battery after it has finished the main charging phase of the leisure batteries. I'm a bit confused after that as the EBL also functions as a charger for the starter battery (float charge) and the leisure batteries and I assume this is from the alternator. The Hymer instruction manual talks about removing the leisure and starter batteries and storing them in an appropriate place to avoid them draining down however I'd want to keep the starter battery in place as it powers the security system. While over winter the panel is unlikely to generate a huge amount daily I wonder if anyone has any advice as to how I can trickle charge the starter battery while protecting the leisure lithium from constant charge?

 

[DuxDeluxe]

I think that eddievanbitz might have a few suggestions

 

[andy63]

When I specced my Hymer ML-T I intended to use it all year round and so the question of what would be required for a winter lay-up never entered my mind however, circumstances this year mean that I will probably have to park it up in it's storage site for several weeks at least, if not 2-3 months and I need some advice as to how best to protect my leisure and starter batteries over this lay-up. My set up is a 200w solar panel, a Schaudt LRM 1218 solar regulator, a Schaudt EBL30 and Hymer's Smart Battery system which consists of lithium and gel leisure batteries. The lithium battery is equipped with a protective function against overload. I'm aware that lithium batteries don't like to be constantly charged but at the same time I do want the solar to trickle charge the starter battery. I don't have a schematic of the system but my understanding is that the solar regulator will start to charge the starter battery after it has finished the main charging phase of the leisure batteries. I'm a bit confused after that as the EBL also functions as a charger for the starter battery (float charge) and the leisure batteries and I assume this is from the alternator. The Hymer instruction manual talks about removing the leisure and starter batteries and storing them in an appropriate place to avoid them draining down however I'd want to keep the starter battery in place as it powers the security system. While over winter the panel is unlikely to generate a huge amount daily I wonder if anyone has any advice as to how I can trickle charge the starter battery while protecting the leisure lithium from constant charge?

Have a look through this thread..
It may provide a solution for you..

Another Battery Master query

If it wasn't for current [and future]lockdowns, I'd visit Vanbitz but hey ho - I have a Solar Panel but as the MH is in storage, the cab battery is slowly losing charge and I can't drive it, would like to fit a Battery Master but have minimal electronics experience - can anyone help with idiot's...

www.motorhomefun.co.uk

It sounds like a battery master type device may do what you want..

also functions as a charger for the starter battery (float charge) and the leisure batteries and I assume this is from the alternator.

I think you are getting mixed up between hook up and mains charging...and when the engine is running and the alternator is charging..
Ie the start battery is getting charged by the alternator when engine is running..it gets a float or maintenance charge off the mains charger when on ehu..
Andy..

 

[RonnieA]

Have a look through this thread..
It may provide a solution for you..

Another Battery Master query

If it wasn't for current [and future]lockdowns, I'd visit Vanbitz but hey ho - I have a Solar Panel but as the MH is in storage, the cab battery is slowly losing charge and I can't drive it, would like to fit a Battery Master but have minimal electronics experience - can anyone help with idiot's...

www.motorhomefun.co.uk

It sounds like a battery master type device may do what you want..

The EBL30 is battery master type device. I'm essentially asking if I need to try to isolate the charge to the leisure batteries as they include lithium.


I think you are getting mixed up between hook up and mains charging...and when the engine is running and the alternator is charging..
Ie the start battery is getting charged by the alternator when engine is running..it gets a float or maintenance charge off the mains charger when on ehu..
Andy..

....and the starter battery gets a float charge from solar which is what I want but not necessarily to the leisure batteries too.

 

[andy63]

....and the starter battery gets a float charge from solar which is what I want but not necessarily to the leisure batteries too.

Think I understand what you are saying..there has been a bit discussion on lithium batteries and a constant float charge provided by the various charging sources even though they are on a lithium profile..that bothers me a bit but seems to be acceptable as the people that make these chargers seem to think so anyway..
Andy..

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[Lenny HB]

I would email Schaudt and ask about the LRM 1218.
I would have thought when set to Lithium it would stop charging when the battery is charged if this is the case does the output to the starter battery still continue to charge.

 

[funflair]

Think I understand what you are saying..there has been a bit discussion on lithium batteries and a constant float charge provided by the various charging sources even though they are on a lithium profile..that bothers me a bit but seems to be acceptable as the people that make these chargers seem to think so anyway..
Andy..

But the people that make the chargers are not servicing the warranty on the batteries or even care wether you get 1000 cycles or 10000 cycles, I think the general consensus is that a lower "float" voltage during storage is better for the cells. This is a good read but may need to be in Google Chrome to translate it.

Ratgeber: LifePO4 im Wohnmobil richtig laden & lagern

Richtiges Laden erhöht die Lebensdauer einer Lithium Batterie umgemein.

www.amumot.de

 

[Pausim]

I'm aware that lithium batteries don't like to be constantly charged

I wouldn’t lose too much sleep about over charging your LiFePO4 battery. They are very forgiving and you have a complex system looking after them. Yes LiFePO4 batteries are happy to be left at 80%, unlike lead acid ones, but keeping them full at the right voltage is not going to ruin them. I suspect that your inbuilt systems will look after it for you.

 

[ManTheVan]

I think I trust manufacturers such as Sterling and Victron who both make and sell their own LiFePO4 batteries and charge controllers, to know the best charge profiles for their products. They’ve spent sizeable amounts on research and development, then decided the most appropriate and efficient settings for their equipment. I therefore selected the built-in LiFePO4 profile on our EHU charger, B2B and solar controller with no hesitation.