Too much charging amperage?

[Hawkeye Ed]

Can you harm a solar controller by connecting too large a solar panel? I have a 200 watt solar panel that I'd like to use to charge my little Jackery 300 "solar generator" but it's way more than the Jackery's input rating of 90 watts.

I don't understand why a solar controller or battery can be damaged by a source with too much amperage. Voltage, yes. But, for instance, a light bulb of the correct voltage can be connected to a source of practically unlimited amperage without damage. Why is a solar controller or battery different?

[Rossue]

Are you sure the max input rating is in watts? My Goal Zero 3000X has a Max input charge of 50 volts. My two Eco Worthy 195 panels wired in series max at 46 volts.

[Hawkeye Ed]

Originally Posted by Rossue

Are you sure the max input rating is in watts? My Goal Zero 3000X has a Max input charge of 50 volts. My two Eco Worthy 195 panels wired in series max at 46 volts.

Yep, Maximum 90 watts:

[Centex]

A given controller's tolerance of input characteristics is likely a function of its specific design and protective circuits / features, IMO it could be costly to make a general statement or assumption in this regard about any specific controller.

IMO it's time to give the folks at Jackery Tech Support a call and give them the full output specs of the panel you propose to use.

I'm not making that assumption but one might construe that the stated limit of 90W@12V=7.5A, and higher current might be damaging. I'd seek explicit case-specific clarification from the manufacturer. YMMV.

Just for your consideration, Have Fun!

[richm]

Originally Posted by Hawkeye Ed

Can you harm a solar controller by connecting too large a solar panel? I have a 200 watt solar panel that I'd like to use to charge my little Jackery 300 "solar generator" but it's way more than the Jackery's input rating of 90 watts.

I don't understand why a solar controller or battery can be damaged by a source with too much amperage. Voltage, yes. But, for instance, a light bulb of the correct voltage can be connected to a source of practically unlimited amperage without damage. Why is a solar controller or battery different?

If the solar panel is too large, here are a couple of ways the solar controller can fail. A common example of damage from too much current is a burned transistor. A common example of too much voltage is a burned capacitor. There are other ways a circuit can fail, but these are very common. It typically takes a fraction of a second, and the capacitor or transistor becomes permanently non-functional.

Solar controllers differ from other loads because an MPPT solar controller is power converter. It converts an input voltage and current to a differing output voltage and current, while conserving most of the power. For certain parts that handle the power, the cost scales with their limits.

To keep costs down, the power limits are tuned to the use case. In this case, the Jackery 300, it's tuned for an amount of time to recharge -- 80% in 2 hours at 90W input.

[Defenestrator]

You'll need to find out the Voc and Isc ratings on the panel specifically and compare that to the Jackery's limits.

Solar panels are weird, in that they don't output a fixed voltage exactly. Under no load they'll rise to their Voc voltage, but pulling power from them will lower that. So, the max amperage and voltage kind of interact. I think generally you can get away with being a little over on amperage and just waste capacity, as long as you're not over or pushing the limit on voltage.

On the voltage side, the limits are.. ambiguous. The manual mentions 22V max solar, but 24V for DC-in from the wall charger via the same plug, then 30V overall max. So, it's a bit unclear which of those is the real limit, but your panel is probably somewhere in the 17-25V range. Might be fine, might be pushing it.

On the current limit side, it looks like it'll take up to 7A but the panel is probably in the 9-12A range for Isc. You can get away with pushing amperage limits a little bit in the supply since it'll generally just not pull as much as it could, but that's quite a bit over. Especially while also being close to the limit or over on Voc. Even if the MPPT controller is smart enough to keep the amperage down, that'll likely push the voltage into the damaging range.

I'd say that panel's too big for the Jackery's input.

[RVlover]

Not necessarily, it depends on the specific functional attributes of the product. Some are equipped with a transfer interface, and some have a protection system. The ideal answer is to call their technical customer service. Like the Infinity 1500 produced by Growatt Portable, with MPPT, the MPPT solar controller is a power converter. It converts input voltage and current to different output voltage and current while saving most of the power. Specific reference:
https://growattportable.com/products...-power-station