Solar regulator not charging batteries

[Herreshoff]

My victory mppt charger is showing charging voltage when the battery leads are disconnected from the batteries but drops down to battery voltage when connected and will not charge batteries. Unconnected voltage is all correct...21.6v etc. by narrowing it down I think it must be the reg.

Anyone know the answer?

[cal40john]

Is this a new install? What do you mean by won't charge, how much time did you observe the charging? What are the system details, battery size, solar panel wattage, etc?

The battery and the rate of charge determines the voltage.
Looking at the charge vs voltage chart in Calder's book a 100 amp-hour battery has a voltage of 12.4 at half discharge. If you hook a 5 amp charging source the voltage would be about 12.6 volts. And at that rate of charge the rise in voltage will be pretty slow.

[zeehag]

how far discharged were batteries. ?
how much capacity are your banks?
i noticed mine will take a few days to actually show charging once they are discharged below 11.5. i have 2 banks each 4 t 105s. and a cranker group 27.
hook up the system and watch it for a few days. this is not immediate resultsville.

[newhaul]

Missing info
What is the size of your house bank?
What is the size of your array?
Big bank with small array = really slow charging

[darylat8750]

What is the amperage?

[foufou]

Best to check charging with an ammeter. As previous commuhave noted voltage will rise slowly while amps are trickling in. With large capacity batteries and smallish solar it will take some time

[bratzcpa]

I have a 3 panel (450 watts total) coupled to a MPPT controller. On a recent trip, I just wasn't getting the performance I thought should be. Actually, the charging was terrible. I messed around with angle of the panels, ran new wiring from panels to controller, etc.

Only in a fit of desperation, I was removing all the wiring and starting over.

It was THEN, that I noticed the ground connection to the battery was connected, but the nut (on top of the battery connection) wasn't tight. It LOOKED perfectly fine. But for some reason, it wasn't allowing electricity to flow properly.

Tightened the nut - - - and all was 100% good again.

So, if it WAS working fine, but now isn't, double (or triple) check your connections - - ESPECIALLY THE GROUND!

[seabreez]

Originally Posted by Herreshoff

My victory mppt charger is showing charging voltage when the battery leads are disconnected from the batteries but drops down to battery voltage when connected and will not charge batteries. Unconnected voltage is all correct...21.6v etc. by narrowing it down I think it must be the reg.

Anyone know the answer?

Ok... Unconnected voltage 21.6v. Connected voltage is what.... when connected does the voltage increase slowly? If it does let it charge. If it decreases... stop thinking... it's the charger. You have to give more information to be able to give you a good guesstimate.

[Paul Elliott]

Also, make sure there aren't any loads on the battery when you are testing. If you are running any lights, radios, gps, etc, that's going to use up power that would otherwise be going into charging the batteries.

But in any case, when connected, the charger output voltage will immediately drop to the battery voltage. It should then slowly rise. Sometimes very slowly. Measure the current if you can.

[Herreshoff]

Ok more info for everyone,

The regulator is about a year and a half old and has been working flawlessly under my old solar set up which was a single 300w panel leading to the mppt controller which is a 75/50 blue Starr victory type (50a) and into three 130ah 12v agm batteries.

The old panel was on my Davits and as I've added a monitor windvane the Davits and had to go and the panel is too bloody big to go elsewhere (2m-3m).
Therefore I bought 9 new 60w mono panels and have divided them into three sets of three (I've only wired in 6 of the 9 so far totalling 360w) and have hinged them off the rails at the stern. (See image)

I've also added a second battery bank of agm batteries of 400ah and have separated them from the older batteries with a battery 1-2-both switch.

The output from the regulator now goes to a 1-2-both switch also so I can allocate where the charge goes.

Ok there are the specs. I was a little reluctant to write all that on here because I don't want to get side tracked into a discussion about how we all wire out solar grids.

Some more info answering people's questions.

The voltage from the panels is coming out at anywhere from 21.6-22.8v and the battery voltage is down to 11.6 as the panels have been no functional for three days now. Took me a while to realise it all wasn't working properly. When the battery cable from the regulator is disconnected from the batteries the cable reads solar voltage (21v) and once connected to the batteries it drops right down to battery voltage and doesn't increase at all. It's worth noting this was happening when the batteries were at 12.1v also so I don't believe it's a low battery issue. I've left it hooked up for a sunny day and it didn't increase the battery voltage.
Also to test it properly I've unwired the isolation switch and run battery cables directly from the reg to the different battery banks and have had the same voltage drop on both when directly connected from the regulator.

I've also tested all the panels separately and checked that non of them are wired incorrectly. All the panels are wired in parallel together and run into the reg with an appropriate cable. I've also tried wiring up my old 300w panel and that too is not charging. I'm thinking it must be the reg even though it's got all the correct lights working and no sign of warning. Hmm,,

It's morning here and I'm about to start working away on it again but th out I should add some more before I do. Will let everyone know what happens today. Should have more info soon.

Thanks

[newhaul]

OK with the info you just provided to me I would have to figure it is the charge controller that is fried. Most of the controllers don't tolerate being disconnected from the batteries with the panels still online

[lonesoldier0408]

Disconnect the panels, reconnect the batteries, reset the controller, reconnect the panels. No charge faulty controller.!!


Still surrounded by anchors.

[Paul Elliott]

Bypass the controller and wire the panels directly to the battery, just for long enough to watch the battery voltage rise. If it does, you've got a controller issue. Make absolutely sure that you won't be delivering raw panel voltage to any electronics or electrical gear. Connect the battery and then connect the panel to the battery.

If the battery voltage doesn't rise, then you have a high-impedance connection in your panel wiring. A DVM will measure full panel voltage when there is no load, but no significant current can be delivered.

[donradcliffe]

This is when a good clamp-on ammeter will pay for itself.

Sears.com

[Herreshoff]

Thanks for the replies.

I will try the advice of connecting the panels (might just connect one panel as to not fry the batteries) and see if the voltage rises that way. If so it will confirm what we all seem to suspect which is that the reg is fried. I'll send it back to the guys I bought it off and hope they send me a new one. If this is the case it's very annoying to have spent so many hours stuffing around thinking it was a mistake I had made and not recognising that it was the fault of the regulator. Boats aye. What can you do.
Thanks everyone.

Niki.