missy avatar image
missy asked

Why aren't my batteries charging faster?

Here are current screenshots of my smartsolar output:

And my battery monitor :

I also have an Orion tr 12/12-30 running.

We have been driving for 2.5 hours today, and have only gone up 1%. We started yesterday fully charged, but used a laptop and inverter for several hours, plus a heater overnight. That dropped us to 76%, 12.63V.

Screenshot from this morning, before we started driving:

I would have thought that we would be recharging quicker given the sunny weather and the Orion (it's new, am I expecting too much of it?)

Ive reread the instructions for the monitor and mppt, I can't figure it out.

We have a fridge running, a fan on low, no other draws.

battery charging
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Murray van Graan avatar image Murray van Graan commented ·

What’s the rating of your panels?

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missy avatar image missy Murray van Graan commented ·

390w, its bifacial so could go up to 500w but I've only ever seen it reach 390!

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2 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

Batteries? Capacity? Settings? Is the shunt wired correctly (pictures)?

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missy avatar image missy commented ·

I have 3 x 100ah agm batteries. The solar was charging the batteries fully in June/July, we hit float most days.

Then August was rainy and cloudy and we dropped to 50% many times, having to charge up with mains hookup.

I thought adding the Orion would make up for the lack of sun during winter. Unfortunately I accidentally bought a non-smart one, so I have no idea how it is performing while we drive.

I'll get a picture of the shunt in the morning.


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Matthias Lange - DE avatar image Matthias Lange - DE ♦ missy commented ·

AFAIK the "old" non-smart Orion's are not designed DC to DC chargers. They are power supplies for loads, not as DC-DC-chargers.

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Guy Stewart (Victron Community Manager) avatar image Guy Stewart (Victron Community Manager) ♦♦ Matthias Lange - DE ♦ commented ·

The new smart Orion is the correct unit for this application. It is possible to use the old units as limited current, continuous voltage, single stage chargers, but they will need to be set up properly, and depending on installation, they may not perform as expected due to voltage drop/differential.

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missy avatar image missy Guy Stewart (Victron Community Manager) ♦♦ commented ·

Well that explains it! I guess it also explains why our starter battery is flat today!

Thanks very much for your help.

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If you can replace the unit to a sympathetic dealer, that would be the best case.

Otherwise, it is possible to raise the voltage output of your current Orion unit to get meaningful charge from it. Though of course be careful not to overdo it. Please see the product manual for more info on how to do this.

It flattening the starter battery is another problem, one that is addressed in settings by the Smart Orion, but for which the non-smart Orion will need another accessory so that it only runs when the alternator is running, and not to flatten the starter battery.

There are SEVERAL accessories from Victron to do this job, eg cyrix, battery protect, argo, and so on.

You will find this very useful:

and also this:

Lastly, it is always valuable to talk to a local expert if you can.

Measure twice, cut and wire once!

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Daniel avatar image
Daniel answered ·

I could be wrong. Are your MPPT, BMV, and Battery in the same Location? Your BMV shows -1°C. Maybe the Charge controller doesn't give out more power because of its cold. I don't know if the MPPT has a Temperature Probe. If you have the temperature sensor on your battery I higly recommend to make a VE.Smart network.

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