Blown inline fuse (1 Viewer)

[Gobcob]

Hi,
Wondered if anyone could offer advice on persistently blowing 15amp inline fuse from solar panel to vehicle battery?
Chausson 640 Titanium, 2020.
Cheers,
Grant

 

[Boringfrog]

Electric problems very difficult to solve without actually looking at it. Do you have a solar controller fitted?

 

[Gobcob]

Yes OV Logic, MPPT Pro

 

[Gobcob]

Sorry PV Logic

 

[Revolvor]

How big is your solar panel?

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[Lenny HB]

Could be the solar controller is faulty and giving out a too higher voltage so in turn the battery is drawing more current.
You need to check the voltage coming out of the controller and also check it in bright sunlight. in bright sunlight. It should be a max of 14.4v (14.7v for AGM) if it's higher than that it will damage the battery.

 

[Gobcob]

How big is your solar panel?

150V

 

[Gobcob]

Could be the solar controller is faulty and giving out a too higher voltage so in turn the battery is drawing more current.
You need to check the voltage coming out of the controller and also check it in bright sunlight. in bright sunlight. It should be a max of 14.4v (14.7v for AGM) if it's higher than that it will damage the battery.

Thanks - original fitter has agreed to send a replacement controller so will try that.

 

[RogerIvy]

Even with a new controller if you still have things blowing you need more info. A clamp meter will tell you what current you’re passing through the fuse.
Also, make sure you’re using good quality fuses - don‘t skimp on that.

 

[Guigsy]

A 150w panel on a really sunny summer's day with a depleted battery is going to be pretty close to 15amps. I thought solar panels could output more than their rating for short periods if they're cool.

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[The TT's]

Having same / similar issue.

PV Logic MPPT Pro controller. 200W Solar.

Leisure battery is AGM, vehicle is, well, a vehicle battery so normal lead acid I guess.

Up until this week was only using the first battery terminal to charge leisure battery from Solar. Garage just fitted second set of wires from vehicle batter to second set of terminals (which only charge when battery attached to the first terminals is in a good place!).

They are fitting 10A fuses though.

Fuse has blown twice in 24 hours.

Just restarted the MPPT Pro controller as I noticed it had something 160 days uptime, just in case it only 'checks' some config on startup as was treating both batteries the same but just clutching at straws!

Did you get anywhere?

 

[Guigsy]

Having same / similar issue.

PV Logic MPPT Pro controller. 200W Solar.

Leisure battery is AGM, vehicle is, well, a vehicle battery so normal lead acid I guess.

Up until this week was only using the first battery terminal to charge leisure battery from Solar. Garage just fitted second set of wires from vehicle batter to second set of terminals (which only charge when battery attached to the first terminals is in a good place!).

They are fitting 10A fuses though.

Fuse has blown twice in 24 hours.

Just restarted the MPPT Pro controller as I noticed it had something 160 days uptime, just in case it only 'checks' some config on startup as was treating both batteries the same but just clutching at straws!

Did you get anywhere?

200w is going to pump a lot more than 10A on the 12v side. Are you saying they've just doubled up the wires? The majority of the current will take the low resistance path.

 

[The TT's]

200w is going to pump a lot more than 10A on the 12v side. Are you saying they've just doubled up the wires? The majority of the current will take the low resistance path.

Just managed to locate the manual online, and perhaps have somewhat answered the question! No idea why they fitted 10A! Might be relevant to OP if they have 15A fuses fitted.

Relevant section below:

This controller is designed to prioritise the battery connected to the ‘Battery 1’ connections first, before then allowing a charge to the battery on the ‘Battery 2’ connections. In practice this means that battery 1 will be around 70% + charged before the controller will start charging battery 2. It will then bring the batteries up evenly to a full charge.

Please note: If charging two batteries that are interconnected on the same circuit (eg in parallel) only connect one battery to ‘Battery 1’ and do not connect the second battery to ‘Battery 2’. Battery 2 connection is only for charging a completely separate circuit with a battery on. For example the engine battery of a motorhome.

 

[Guigsy]

Just managed to locate the manual online, and perhaps have somewhat answered the question! No idea why they fitted 10A! Might be relevant to OP if they have 15A fuses fitted.

Relevant section below:

View attachment 792656

I'd make sure the wire gauges are up to 20A too... attention to detail, and all that.

 

[Cuky's]

Hi,
Wondered if anyone could offer advice on persistently blowing 15amp inline fuse from solar panel to vehicle battery?
Chausson 640 Titanium, 2020.
Cheers,
Grant

Hello, had same problem, came down to smart alternator. Had isolator switch fitted to vehicle battery charge line from MPPT which I use before starting engine then back on again when parked up.. Otherwise blows every time when engine runs.

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[Blue Moon]

Hello, had same problem, came down to smart alternator. Had isolator switch fitted to vehicle battery charge line from MPPT which I use before starting engine then back on again when parked up.. Otherwise blows every time when engine runs.

I've a similar problem. Is your vehicle a Fiat Ducato and do they all have smart alternators? My 20amp fuses to both the starter battery and every now and again the leisure battery blow. Could it be the alternator and do I need an isolator switch on both separate feeds?