Battery charging saga

[fesimone]

I've been reading about battery separator, solar charging, alternator charging, etc.

The van came with a 4D AGM, Triplite interver and pre-wired for solar. I just installed two 68W Solar panels and two weeks after I hear the separator cycling when the solar is providing charge (cycling between 13.2 and 12.8). Also read the similar clicking have been heard by other SMB owers.

My questions are the following:

1) Will I damage my starting battery with the solar controller set to output 14.4V (at 80F) as per AGM manual given the starting batt isn't AGM?

2) Say house batt is fully charged through solar controller at 14.4V. If I were to start engine then alternator would supply 14V which would then discharge the house battery a little?

3) If above are true, I might think about adding a switch to disable the battery separator so that the solar only talks to the house battery and the alternator to the starting battery. Confirm this is done by disconnecting black wire from sure power separator that goes to ground.

[jage]

If you have the SurePower 1315, there are 3 small tabs, one of which is "Starter" or something (Start Lamp, Starter, Neg). It will only join if charging on either side is above the threshold, or if the Start tab is powered.

If your house is dropping when you start, then you probably have wire that always connects the Separator on start, which would be a wire supplying 12v to the Start tab. Otherwise the batteries are disconnected, or the house are full enough (charging and connected) that the drop won't matter.

I believe you can put a switch on the negative tab to interrupt the SurePower, but I can't recall if that's the only ground, I don't think there would be another, but it should be obvious. I prefer manual control and would personally add a Start switch (power to start tab) and an Off switch (interrupt ground).

Let me know what you find.

[daveb]

Are you seeing high amperage charging that doesn't taper down? I don’t know what type controller you have but think you’re looking at the solar bulk rate charging voltage. Mine has two charging voltages/rates. On the Blue Sky solar boost 2000, the constant charge voltage is lower and can be adjusted plus after all the batteries are fully charged, the controller will only put out about 0.6 amps or so. That’s practically nothing. It's high amperage overcharging to avoid. Hot weather would probably have more effect on wet cell battery level than the solar if that's what you're worried about. I prefer that the solar charges my starting batteries; is what keeps the chassis system up to par in most cases. I think more people damage their batteries by letting them get too low. I did have my wet cell batteries fail twice in 3 years and I can't say the solar didn't do it but it was always one battery. On the first set I lost, I put the good battery in my truck and it worked for a few years until I let it go dead.


Adding a switch to keep the separator open can be done like Jage posted but it might be wise to check with the manufacture to see if it will cause any damage to the separators electronics. I just don’t know. More than likely it won’t. I went through a few of those Surepowers when they would stick open and used the ground wire to rapidly open and close it to make the separator work correctly. Finally switched to Blue Sea 7622 with the full control option.

[jage]

Originally Posted by daveb

Finally switched to Blue Sea 7622 with the full control option.

That's what I did, except the Blue Sea 9112. Oh, and it only took me one fried SurePower.

[fesimone]

Adding the switch did the trick of disabling the battery separator. It's not a permanent fix since why have a separator if the switch would disable it?

It will allow me to diagnose why the separator keeps clicking when solar is charging both house and start batteries and algo give me some time to see if 14.5 V would damage the starting batteries.

I do have the Blue Sky Solar Boost 2000 and I do understand that at 14.5 it is a trickly charge, but nevertheless, I am not sure if letting it stay at that voltage for long periods of time could do damage. The best solution would be to swap the starting battery for the same chemistry as the house, in my case AGM.

As far as the clicking, I wonder if other separators allow you to set the separate on/off voltage as it may that in my case a wider range might prevent the clicking.

[Scalf77]

There have been other discussions of mismatched batteries between house and van. I think while it sounds like it could be a real problem, it doesn't appear to surface as one. I had my van battery last 5 1/2 years, plugged into shore power while parked at home.

As far as the cycling of the separator, what is the time frame we are talking about? You are probably going to have to monitor your voltage levels at the separator. I take this is with Solar? If so have you tried Shore power if possible? If you voltages are dropping below the set points after being connected, the separator would be working as expected. Is this a new van, or I should say new separator?

[fesimone]

Separator/Van are year and half old. Solar panels are two weeks old.

Yes, separator seems to be performing as spec'd. The cycling is every minute or so. When solar it tries to charge both batteries but the voltage drops below speparator spec and it separates batteries, then voltage rises to above separator specs and it joins both banks. This cycles repeats until I assume both batteries are charged enough so that separator keeps them joined.

Maybe I should find out what's the mean service time of these separators (how many times it can click).

[Ford_6L_E350]

I turned my solar controller down to ~13.6V. It still keeps everything charged, but it eliminates any concerns about overcharging. The separator still clicks and keeps all batteries up.

Mike

[daveb]

Originally Posted by fesimone

Separator/Van are year and half old. Solar panels are two weeks old.

Yes, separator seems to be performing as spec'd. The cycling is every minute or so. When solar it tries to charge both batteries but the voltage drops below speparator spec and it separates batteries, then voltage rises to above separator specs and it joins both banks. This cycles repeats until I assume both batteries are charged enough so that separator keeps them joined.

Maybe I should find out what's the mean service time of these separators (how many times it can click).

Something is not right. Once the sun powers up the panels, the separator should see the rise in voltage and click closed and stay closed until something pulls enough amperage to lower the voltage of either battery systems to below 12.8v. Same with the vehicle's alternator at night. Once the alternator puts out its charge voltage (usually about 14.2), if the separator is open, it should click to the closed position and stay closed until the engine is shut down and something pulls either of the battery system's down below 12.8v.

I'd be looking for a poor connection somewhere. You might also want to ohm out the separator as well. With the separator open, check each battery system after you've charged everything up. There should not be too much of a voltage drop after engine shut down and the batteris should stay above 12.8 with nothing being used for several minutes.

[Ford_6L_E350]

Depending on how much sun is hitting the panels and at what angle, there may not be enough charge current to keep all the batteries above 12.8V.

A 4D is a huge battery, and if he has a diesel with 2 starting batteries and with a low winter sun angle he may only be getting 3-4 amps of charge current. It may be enough current to get the 4D up to 13.2V, but not enough to keep it above 12.8V when the starting batteries (~12.5V) start to charge up.

I hear the same clicking on and off when the solar gets the house batteries up and then starts to charge the starting batteries. After a couple of cycles it stops clicking.

Mike