Charging onboard Lithium battery after swapping existing leisure battery

Dr Who

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Urgent request - Can someone please guide me on what I need & how to charge 12v lithium ion leisure battery from 12v DC alternator; currently charging wet leisure battery. Thanks
Haven't had much luck to enquiry in the past. Perhaps better luck this time.
No solar panels yet.

ps. any suitable charger for when they are kept in the garage.
 

wildebus

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2,216
I think it would be useful to post the actual model of the battery as well. Something that is critical is not charging the typical lithium battery at around or below 0C - and we are at that time of year where batteries can get very cold!
 

Okta

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I use a Votronic VCC1212-45 battery to battery (b2b) charger, it has a range of settings to suit most LiFePO4 batteries. Lithium ion is a generic term for several types of battery with very different chemistries and characteristics but the ones sold as leisure batteries are usually LiFePO4. As already said by @wildebus charging below freezing can be a problem. I have added a switch on the D+ connection to the b2b so that I can stop it cutting in if it is freezing but the built in battery management system should protect the battery. I have a Relion battery and the manufacturer gives the following advice:
Charging Temperature LiFePO4 batteries can safely charge between -20°C to 55°C (-4°F to 131°F). However, at temperatures below 0°C (32°F) the charge current must be reduced, until the temperature is >0ºC (32ºF), as follows:
1. 0°C to -10°C (32°F to 14°F) charge at 0.1C (10% of the battery capacity)
2. -10°C to -20°C (14°F to -4°F) charge at 0.05C (5% of the battery capacity)
This means that for Relion batteries lower charging rates from Solar/Efoy are unlikely to be a problem but fast charging has to be avoided below freezing point.
 

Dr Who

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Thanks for your comments.
It isn't in situ yet.
I thought it would be a straight swap. But reading the forum comments it doesn't seem so straight forward as that.

The nearest motorhome service station will only fit items I purchase through them and neither fit items bought elsewhere even if it is the same as they would fit.
So am sitting on previously purchased air suspension, diesel heater and LiFePO4 battery.

The link to the battery on eBay is:


Hope this helps to get some further assistance.
Thanks
 

jagmanx

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1,266
Money Money Money.
I had a similar problem when I asked a motorhome repairer/dealer to do what I wanted.
I suspect the cost would have been towards £1000
He would only quote if I agreed to a full habitation check.
I suspect the said habitation check would have revealed "Many issues that needed Fixing" Thus a huge repair billl.
Needless to say I declined his kind offer to potentially relieve me of a substantial sum maybe £2000 plus ?
Call me cynical !
 

Okta

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427
I am a teeny bit suspicious of the one that claims to be 300 Ah and weighs only 14.5 kg. My Relion is 100 Ah and weighs 13.5 kg and the Relion 300 Ah one weighs 37.5 kg. Something does not add up.
 

Dr Who

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Having saved for and got it, gotta get it fitted and in use asap.
It was relatively easier to lift in the habitat while waiting to be swapped than the Banner I was advised as a previous replacement to a dying leisure battery.
 

wildebus

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2,216
Urgent request - Can someone please guide me on what I need & how to charge 12v lithium ion leisure battery from 12v DC alternator; currently charging wet leisure battery. Thanks
Haven't had much luck to enquiry in the past. Perhaps better luck this time.
No solar panels yet.

ps. any suitable charger for when they are kept in the garage.
Oh, this recent video may be interesting as well...

 

Froodie

Full Member

Messages
89
The nearest motorhome service station will only fit items I purchase through them and neither fit items bought elsewhere even if it is the same as they would fit.
So am sitting on previously purchased air suspension, diesel heater and LiFePO4 battery.
They are not interested in case something goes wrong. Then who pays to put it right. If they fit the Air Suspension for you and it leaks who fits the replacement and who pays. They also make a profit out of what they sell and you get a guarantee.

Sometimes they have repair meets where people with problems turn up and people who know how to fix them fix them.
 
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Trek

Free Member

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557
You won’t like my suggestion but here goes anyway

Keep things simple

Sell the new lithium battery and install a new top quality lead acid battery

That way you won’t have to make any changes to your existing chargers wiring etc and not have to worry about low temperature issues


Something that would be a BIG issue for me as we use the camper in the winter
Seems a bit daft if you need to have a heat pad around a lithium battery in the winter. What powers the heat pad , a lead acid battery ?
 

Okta

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427
There is no real problem with Li and winter use, the battery stays well above freezing when the motorhome is in use. The only time temperature might be an issue is when it has been left cold and unattended and then it is just a matter of limiting heavy charging until it has warmed up. I would turn the B2B off if I needed to but it has not been a problem yet. Lithium batteries do not self discharge when left so the probability is it will still be fully charged from the previous trip.

If you did want to use a 12v heating pad an Li would be perfectly capable of powering its own pad.

I haven’t changed my mains charger, the gel setting is fine.
 

Dr Who

Full Member

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14
You won’t like my suggestion but here goes anyway

Keep things simple

Sell the new lithium battery and install a new top quality lead acid battery

That way you won’t have to make any changes to your existing chargers wiring etc and not have to worry about low temperature issues


Something that would be a BIG issue for me as we use the camper in the winter
Seems a bit daft if you need to have a heat pad around a lithium battery in the winter. What powers the heat pad , a lead acid battery ?
Thanks. All suggestions are welcome, else I'll learn nothing.The additional items I plan to add to the moho means I have to take weight into account, hence the change of batteries, plus the lifecycle and the power delivery of the battery over time.
 

Dr Who

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14
There is no real problem with Li and winter use, the battery stays well above freezing when the motorhome is in use. The only time temperature might be an issue is when it has been left cold and unattended and then it is just a matter of limiting heavy charging until it has warmed up. I would turn the B2B off if I needed to but it has not been a problem yet. Lithium batteries do not self discharge when left so the probability is it will still be fully charged from the previous trip.

If you did want to use a 12v heating pad an Li would be perfectly capable of powering its own pad.

I haven’t changed my mains charger, the gel setting is fine.
That's interesting regarding the mains charger. At the moment I am using a ctek charger for when charging the lead battery directly from the mains. Unless I hear to the contrary perhaps I could do the same here. The ctek adjusts it's charge accordingly and then goes into low maintenance mode. Useful when I'm when I'm not using the car for a long period.
 

Okta

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427
That's interesting regarding the mains charger. At the moment I am using a ctek charger for when charging the lead battery directly from the mains. Unless I hear to the contrary perhaps I could do the same here. The ctek adjusts it's charge accordingly and then goes into low maintenance mode. Useful when I'm when I'm not using the car for a long period.
I don’t know about CTEK but the CBE charger in my van has a 14.3v output for gel batteries which is ok for my Li Relion. It might not achieve the maximum charge but it doesn’t need to if I am on a hook up. The B2B does a full charge when I am driving and my Efoy maintains it when I am off grid.
 

Trek

Free Member

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557
Some CTEK chargers include a temperature sensor probe to alter charge if battery (lead acid) is cold

Don’t know about using them with lithium


But they now do a charger for lithiums :- https://www.ctek.com/products/vehicle/lithium-xs

Just found following but its not showing on their product description for existing CT5 POWERSPORT and this model is for smaller batteries like motorbikes and mobility buggies :-
Changes to CT5 POWERSPORT charger
(Europe only)
We’ve made some exciting changes to the European model of our CT5 POWERSPORT charger…
We’ve now introduced a dedicated lithium programme and there are some other changes too


 
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wildebus

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2,216
Must say I didn't notice that. (I would have thought a boat would have an engine starting battery for its diesel engine same as a vehicle?)
 

Okta

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427
My boat did. A single battery reserved for engine stating on one engine and a double bank on the other for domestic use. They could be linked for engine starting if needed. When I had a single engine there were still separate banks for engine starting and domestic use, with a split charge arrangement that favoured engine battery charging. Ever tried bump starting a boat? :)
 

xsilvergs

Full Member

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41
Do any of you have experience of alternator temperature sensing? Are there any off the shelf kits you could recommend?

I am thinking of this for my own LiFeP04 project but should the alternator exceed a set temperature I will just turn off the B2B until it cools down.

The max B2B current will only be 60 amps so not excessive, more a precautionary measure.
 

Philip Tomlinson

Administator

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1,617
Do any of you have experience of alternator temperature sensing? Are there any off the shelf kits you could recommend?

I am thinking of this for my own LiFeP04 project but should the alternator exceed a set temperature I will just turn off the B2B until it cools down.

The max B2B current will only be 60 amps so not excessive, more a precautionary measure.
If your motorhome has a Bosch alternator (most Sevel and Iveco vans do) then it will most likely have a Bosch cr719 IC controlling it. This voltage regulator cuts the charge current down if the alternator gets above 150c which is a perfectly safe temp for the alternator. If it has a different brand or a an old alternator it may be worth checking.
 
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