Charge controller for multiple sources

[cha0s]

Mmmm ok. Thanks for all those responses. We don't have a smart gauge (yet) but we are often dropping to 11.9v/12v when the refrigerator and freezer run all night.
We are almost never on shore power (but we are right now) but we do use the generator to run the 240v charger. Even when batteries are at 11.9v the tong tester only shows 30amps coming out of the 120amp 240v charger.

Even when the batteries are showing 11.9v on (via multitester). When this is the case the solar charge controller says that the out put voltage is about 13.6. This seems to change based on how much sun there is rather than the soc.

When I've tried to tong test the alternators under these same conditions they seem to be making about 2 amps.

For the last 6 months we have been cruising and it is a constant battle to keep charge in the batteries. Even with engines running 6 hrs a day we still have to run the generator for 3 hrs a day. And we are on the equator and have had very few cloudy days.

I will have to play around with these voltage set points that are mentioned. I've not done that before.

[belizesailor]

Hmmm...that sounds like a dying battery bank to me...high acceptance and minimal capacity.

[Jetx]

Originally Posted by cha0s

Even when the batteries are showing 11.9v on (via multitester). When this is the case the solar charge controller says that the out put voltage is about 13.6. This seems to change based on how much sun there is rather than the soc.

I'd confirm this with multimeter, measuring voltage directly at the battery terminals, and at the output terminals on the controller. But if these voltages are accurate, that's a huge voltage drop (high resistance) between the controller and the batteries.. and your solar is barely even contributing to charging the batteries.

In that case, check connections and resistance between the controller and the batteries. Or replace wire from controller to batteries with larger gauge.

[Jetx]

Originally Posted by belizesailor

Hmmm...that sounds like a dying battery bank to me...high acceptance and minimal capacity.

With dying batteries, I'd think you'd have low acceptance (low charge current) together with high voltage a at the battery terminals. No?

[newhaul]

Originally Posted by cha0s

Mmmm ok. Thanks for all those responses. We don't have a smart gauge (yet) but we are often dropping to 11.9v/12v when the refrigerator and freezer run all night.
We are almost never on shore power (but we are right now) but we do use the generator to run the 240v charger. Even when batteries are at 11.9v the tong tester only shows 30amps coming out of the 120amp 240v charger.

Even when the batteries are showing 11.9v on (via multitester). When this is the case the solar charge controller says that the out put voltage is about 13.6. This seems to change based on how much sun there is rather than the soc.

When I've tried to tong test the alternators under these same conditions they seem to be making about 2 amps.

For the last 6 months we have been cruising and it is a constant battle to keep charge in the batteries. Even with engines running 6 hrs a day we still have to run the generator for 3 hrs a day. And we are on the equator and have had very few cloudy days.

I will have to play around with these voltage set points that are mentioned. I've not done that before.

ok well with everything you now have given us I would have to say you have some issue with your wiring .

[newhaul]

Originally Posted by Jetx

With dying batteries, I'd think you'd have low acceptance (low charge current) together with high voltage a at the battery terminals. No?

depends on how his battery bank is wired if they are daisy chained then all it would take is one loose connection . To really do things in. What we really would need is voltage readings on each battery in the bank. ( kinda hard to diagnose from half a world away. Pictures help)

[belizesailor]

Originally Posted by Jetx

With dying batteries, I'd think you'd have low acceptance (low charge current) together with high voltage a at the battery terminals. No?

Depends on the nature of the issue with the batteries, but yes many times Ive seen older batteries which would just keep taking juice...may even come up to good voltage range...and then have a small load deplete then quickly.

[belizesailor]

The original issue posted is a non-issue, they will play just fine together, but something else is amiss here: battery condition, wiring issue, inaccurate meter readings...?

[cha0s]

Th battery bank was new in April so 7 months old. The reason I thought the original issue was an issue was because I have destroyed 2 x 120amp alternators and potentially by the sound of it my battery bank in 7months.
We are pulling about our 10amps out of the battery's all the time (predominantly refrigeration) and quite a bit more ,(maybe 10 amps) when the engine room blowers and autopilot are on. Unfortunately the having engines running doesn't provide more than a couple of amps to offset the additional draw from blowers and autopilot.
Thanks for your input everyone. I will try to figure it all out. I never did anything special about setting voltages of chargers. I just selected agm on the charger. I have a switch on the solar so can turn it off when underway, but have not done that in the past because the charge for from the alternators was less than from the solar.
Have new regulators and alternators on the way so hope they fix the prob.

[belizesailor]

Originally Posted by cha0s

Th battery bank was new in April so 7 months old. The reason I thought the original issue was an issue was because I have destroyed 2 x 120amp alternators and potentially by the sound of it my battery bank in 7months.
We are pulling about our 10amps out of the battery's all the time (predominantly refrigeration) and quite a bit more ,(maybe 10 amps) when the engine room blowers and autopilot are on. Unfortunately the having engines running doesn't provide more than a couple of amps to offset the additional draw from blowers and autopilot.
Thanks for your input everyone. I will try to figure it all out. I never did anything special about setting voltages of chargers. I just selected agm on the charger. I have a switch on the solar so can turn it off when underway, but have not done that in the past because the charge for from the alternators was less than from the solar.
Have new regulators and alternators on the way so hope they fix the prob.

You've got 120A alternators and only getting a few amps?

I also just reread some of these posts an noted you are only getting about 25a from 1.2Kw solar. I get that from 375W solar...something is way wrong,

Again, something is seriously amiss here...add big ground fault to list of possibities.

Unfortunately, this is gonna be hard to diagnose without being there with a good multimeter in hand...DC Clamp On so you can figure out where all those amps are going, or not going, from that big solar and big alternators.

[mickt243]

Originally Posted by cha0s

Even when the batteries are showing 11.9v on (via multitester). When this is the case the solar charge controller says that the out put voltage is about 13.6. This seems to change based on how much sun there is rather than the soc.

If the above is accurate, you have a wiring fault.

If your wiring is decent, the output of the charger and the multimeter on the battery post will be within 0.1v of each other.

[waterman46]

The reason for having large capacity in your 120/240VAC charger, is to be able to run all of your 12/24VDC equipment (watermaker, freezer, fridge, microwave) at the same time you are charging your batteries at the bulk charge current rate. This situation happens regularly when using an AC generator at anchor, if your wind and solar have not been producing much power due to lack of wind and sun.