Battery Charging (1 Viewer)

[Heebson]

So I’ve had a problem already with my 2019 AutoSleeper Neuvo with the alternator not charging the leisure battery that got the main unit sent back to Sargent.

Now, six months ago on, I’ve replaced the lead leisure battery with a Lion battery. The thing is, I’m still not convinced it’s working as it should. When driving, with the battery’s app, I’m seeing ~2 amps/25 watts being delivered.

We’ve also had amazingly sunny days, but looking at the monitor, it flicks between 0 and say ~2+ amps, but I don’t think the battery is being charged.

This make any sense? I’ve six months left on purchase warranty, so need to decide whether it’s a claim, or just the way it is…

Thnx
Heeb

 

[Tombola]

No that's not right.
What make of battery is it and how much solar do you have.
Do you have a b2b installed too.
Maybe as simple even as the app needs resetting ot could be as bad as a dud battery or break in the connection somewhere.

 

[GeoffnDee]

Could it be because the battery is fully charged ?

 

[Lenny HB]

On another thread someone mentioned Neuvo's have a smart alternator but no B2B and they would fit one under warranty if the customer complained.
That won't answer why your solar isn't charging.

Run the battery down to about 80% then check what happens.

The standard Sargent solar controller will not be suitable for Lithium neither will the mains charger so they both need changing anyway.

 

[Heebson]

The numbers I quoted were probably at about 70% charge. It charges absolutely fine when on EHU.

The solar came with the van, think it’s about 100w. The battery is about a year old as the previous (original) was gubbed - I now suspect from these charging failures.

I’d certainly read about the solar controller being iffy and had planned to replace once warranty expired, but just wanted to make sure that the numbers/behaviour I’m seeing is well out - this is our first van, so nothing to compare it with.

Thnx,
Heeb

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[autorouter]

When driving, with the battery’s app, I’m seeing ~2 amps/25 watts being delivered.

More info needed. As has been said, if the battery is full, then nothing will charge it, alternator, solar, mains etc. If it's down to 80% or lower then it should be charging.

So, what voltage does the app report, and are you sure the amps is flowing into the battery, not out of the battery? Watch the voltage over time. After a few minutes, if it's a smart alternator, the starter battery stops charging and the voltage drops to maybe 12.5V. What is the amps at that point? And be sure to notice if it's into or out of the battery.

I’ve replaced the lead leisure battery with a Lion battery.

I'm presuming you mean a lithium battery, not a Lion battery which is a brand of lead-acid battery.

 

[sfrain145]

Charging systems are very strange on the factory builds, the Smart Alternator reads some wacky stuff mine works on idle great driving not much goes back into either battery however when coasting down hill it ramps up to 14v plus so threw me a bit but apparently its to do with Euro 6 and all that good stuff, no idea but what I do know is Lithium batteries need more fancy devices than what is fitted to these vans.

 

[Heebson]

Whoops, yes, Fogstar 105Ah Lithium. They did say when investigating the earlier problem that the charging profile should be fine.

Voltage whilst driving is around 13.4/13.6, Amps about 2. What caught my eye was the simple fact that after a very sunny morning, then a 2+ hour drive, the battery had hardly charged at all (from around 65%). Once plugged into EHU, amps jumped to 9 and the battery charged fully.

 

[Lenny HB]

I’d certainly read about the solar controller being iffy and had planned to replace once warranty expired,

Change it now as it is not suitable for Lithium, same with the mains charger.

 

[Lenny HB]

Whoops, yes, Fogstar 105Ah Lithium. They did say when investigating the earlier problem that the charging profile should be fine.

Marketing BS, always best to fit the correct chargers with Lithium

Voltage whilst driving is around 13.4/13.6, Amps about 2

It's never going to charge at that voltage it needs 14.1 to 14.2v

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[Pausim]

If Auto Sleeper are not fitting a B2B then you will have a split charge relay and this is likely the cause of all your problems. When the engine is running and the relay joins the 2 batteries together the higher voltage lithium battery is likely to be pushing charge the wrong way through the relay to the engine battery. The smart alternator will be sensing the higher voltage and not cutting in, it is probably quite happy to let your solar panel feed both batteries.

 

[autorouter]

It's true that if you're worried about damaging the lithium battery then a voltage of 13.5 or 13.6V 'should be fine', ie won't cause any damage. However it certainly won't charge it anything like full.

The whole point of a smart alternator is to save fuel by dialling back the charging when the engine is running normally, so that the load on the engine is reduced. When you take your foot off the pedal, or use the brakes, the smart alternator reacts by turning up to full power and charging the battery, applying a load to the engine just as you are trying to waste energy anyway. So in that sense it's not using any extra fuel to charge the battery. It always keeps enough charge in the starter battery to start the engine, but never fully charges it.

If a split charge relay is used, the leisure battery gets the same treatment as the starter battery, which is nothing like what you want. A B2B takes power from the alternator at whatever voltage it happens to be, and boosts it up to the correct voltage for charging the leisure battery. And when it's full, it dials back the voltage so that the leisure battery is not overcharged.

It sound to me like your battery is fine, and if 13.6V is applied then 2A is what I would expect. It needs a higher voltage, which is what a B2B will provide. The manufacturers should have pointed out that it will never charge from the alternator while driving, and you should rely on the solar and EHU to properly charge the leisure battery.