New to solar, will I have battery issues later on. (1 Viewer)

[FrankNicklin]

Recently purchased a 100w folding panel with a simple MPPT controller. The controller just shows solar input, charging and charged through 3 LEDs. The panel is currently in the windscreen and luckily facing south if I drive in to my storage spot rather than reverse in. In this weather as expected the output varies considerably and not the steady output you would get from a regularly mains intelligent charger. I have split relay charging on the road and when off grid a few days at a time such as festivals, the idea will be to charge the leisure battery and use a battery master to top up the vehicle battery but I need to get my head around the wiring first, it’s a 21 year old MH. Vehicle battery is Varta 95ah and leisure is 105ah. Both are standard wet lead acid batteries.

I have attached a BM2 to both batteries, the leisure battery is fine and hasn’t dropped at all, but as you would expect the vehicle battery does. Over the dull days VB will drop to around 65%. It’s not dropped below that before we take the MH out. To my surprise a few days ago the BM2 was reporting fully charged at 100%, happy days. When looking at the input via the BM2 app, you can see the voltage variation over time, will this harm the battery.

Below is screenshot from Vehicle Battery BM2 2 days ago.

Below is the BM2 recorded voltages over 15 days.

 

[Raul]

Those BM is it a shunt based monitor? If it isn't, I would take those estimates with a pinch of salt.
Even so, sounds like you have a load on the starter ( radio?) or a goosed starter batt and heavy self discharge.

 

[Guigsy]

If it was a car that did a couple of short trips per day, it's battery voltage would jump around a lot more than that.

 

[FrankNicklin]

Those BM is it a shunt based monitor? If it isn't, I would take those estimates with a pinch of salt.
Even so, sounds like you have a load on the starter ( radio?) or a goosed starter batt and heavy self discharge.

All vehicles have a load on the battery, such as radios and ECU's etc. I'm not concerned about the charge rate just the impact on the battery over time, if there is any.

 

[Raul]

Yes all vehicles have a quiescent current, some more than others. But also some have enough load to bring a weak battery down. And some radios do discharge the battery,and requires a total isolation, pioneer rings a bell.
I haven said anything about the charging rate as I don't know your system and your charging capabilities.
My direct question was TYPE of battery monitor, is it a shunt or just voltage guesstimator?

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[FrankNicklin]

Yes all vehicles have a quiescent current, some more than others. But also some have enough load to bring a weak battery down. And some radios do discharge the battery,and requires a total isolation, pioneer rings a bell.
I haven said anything about the charging rate as I don't know your system and your charging capabilities.
My direct question was TYPE of battery monitor, is it a shunt or just voltage guesstimator?

No these are guesstimators not shunts. I'm only using as guidance for battery state at the moment for the purposes of knowing if the Solar is actually doing anything for me. I realise there are far more effective methods out there with Shunts etc which if the solar panel was a permanent fixture I would invest in. As this is a portable unit sat on the dashboard I just needed to have some indication of battery state. The device just connects across the terminals and an app reads the data via bluetooth, its as simple as that. I'm not expecting 100% accuracy but just indicative values for now.

 

[bigtwin]

FrankNicklin, if you’d like a proper interpretation of your situation you’d do well to answer @Raul’s question.

My direct question was TYPE of battery monitor, is it a shunt or just voltage guesstimator?

The question is rooted in an in-depth understanding of vehicle systems. The graph you presented may be important, but it may not.

Ian

 

[FrankNicklin]

FrankNicklin, if you’d like a proper interpretation of your situation you’d do well to answer @Raul’s question.


The question is rooted in an in-depth understanding of vehicle systems. The graph you presented may be important, but it may not.

Ian

I thought I had answered the question. Response #6, apologies if the detail is insufficient. As I mentioned I'm new to solar and MH electrics.

 

[Raul]

No these are guesstimators not shunts. I'm only using as guidance for battery state at the moment for the purposes of knowing if the Solar is actually doing anything for me. I realise there are far more effective methods out there with Shunts etc which if the solar panel was a permanent fixture I would invest in. As this is a portable unit sat on the dashboard I just needed to have some indication of battery state. The device just connects across the terminals and an app reads the data via bluetooth, its as simple as that. I'm not expecting 100% accuracy but just indicative values for now.

In that case, voltage matters, but the percentage estimate can be out,
If the voltage does not drop below 12.45-12.5v the starter batt still has life left in it.

 

[bigtwin]

I thought I had answered the question. Response #6, apologies if the detail is insufficient. As I mentioned I'm new to solar and MH electrics.

Our posts crossed. I saw yours (#6) only after I‘d posted mine (#7).

Ian

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[FrankNicklin]

In that case, voltage matters, but the percentage estimate can be out,
If the voltage does not drop below 12.45-12.5v the starter batt still has life left in it.

Thank you, I will be using the MH through the winter so will hopefully be out and about in the next few weeks. Just wanted to know that the battery was still good enough to start the MH when needed.

 

[Raul]

My van has a smart alternator, and many times the starter is at 12.4-12.45v. The battery is original since dec 2017, still going well. However, I do have a noco battery starter on board just in case it packs up. I will only change the starter if it can’t start it in winter.

 

[FrankNicklin]

My van has a smart alternator, and many times the starter is at 12.4-12.45v. The battery is original since dec 2017, still going well. However, I do have a noco battery starter on board just in case it packs up. I will only change the starter if it can’t start it in winter.

Thats useful to know. I don't know the age of the battery on ours. The MH is 21 years old and only owned since October, but I have to say it starts first time everytime. I was concerned about the impact on the cold weather whilst in storage but when possible I do take it out for a run occasionally even if we are not going away, just to keep things moving.

 

[berni109]

The profile from the BM2 is much the same as mine with a direct feed from my solar controller.
The battery master is doing its job as it's seeing the VB needing a daily top-up.
How long will our VB last as they are both loosing power each day?
I have no idea but I won't be doing a continental tour without changing it. I also carry some long jump leads just in case it suddenly decides to die.

 

[CAB96]

The BM2 is a Bluetooth voltage monitor, but it logs for several weeks.

If you search you can get an Android app (not on the app store as far as I know) which can connect to and display up to 4 BM2s at once. Let me know if you think that would be useful, I will search out where I got it from.

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[FrankNicklin]

The BM2 is a Bluetooth voltage monitor, but it logs for several weeks.

If you search you can get an Android app (not on the app store as far as I know) which can connect to and display up to 4 BM2s at once. Let me know if you think that would be useful, I will search out where I got it from.

I have the app for my iPhone, thats where the screenshots came from.

The multi-device app for the BM2 is £9.99 on the Apple store.