Simple Dual Battery Set-up Gone Wrong

[ofmountainsandbeaches]

Apparently I did not do my homework.. I was never any good at homework back in the day and now it seems like I'm paying for it more than ever.

Currently situated in Guatemala where everything is cheap, but you can never find what you actually need. Back to the beginning..

In early January 2016 I had quit my job and was rushing through the final stages of my Mitsubishi Delica camper conversion and hooked up my starter battery to my new Optima Yellow Top aux battery parallel via a Blue Sea Isolator (Which then powers an inverter, fuse panel to fridge, stereo etc.). Also hooked up a 150W solar panel to my AUX for when we're camped out for a few days. This came with a solar controller. System seemed to work great. Beers were cold, the van started.. what else mattered? I tested the AUX battery en-route in California and it lasted 3 days without needing any solar power. Awesome.

Fast forward 4 months and now my Newish Optima Yellow Top only lasts 4-8 hours from a 'full charge'. I noticed a few weeks ago (after being frustrated enough to investigate this power loss) that the main starter battery was draining 3-4 amps constantly until the AUX battery voltage dropped enough for the isolator to kick in (or out, however you'd like to call it). So I've been manually connecting the main battery to the isolator every time we drive then disconnecting every time we stop. Quick fix, yet my AUX still has very little Ah capacity. I've contacted Optima Batteries but they simply dirrected me to their FAQ webpage :violent-smiley-031:

Is it possible to try to revive this Yellow Top? I also just noticed the Equalizing setting on my solar charger was turned off (and now haven't had sun in a few days to try that out) Will this help? What is the best way to charge and then test it?
Do I Move this Yellow Top to be my new starter battery then buy the same Yellow Top as an AUX? Or would my current Yellow Top be too damaged to do this now?
Would all this excess charging cook my starter battery? It seems to have a lot of corrosion and water marks from overflowing. Should I test this one as well?

Reading more now, I see that I should have installed a solenoid. Would this have prevented my issues from arising?

Any helpful information/wisdom would be MUCH appreciated!

 

[Chris Boyd]

How was the yellow top being charged before this episode?

If the yellow top is not holding a charge from full it may be hosed from not being fully charged each cycle. It can possibly be refreshed but only using the optima charger which does a full charge at the proper voltage. Which by the way is around 14.2 but can be as high as 15.0 IIRC with most any amperage. I'd have to look back at the datasheet to be sure.

If you run in parallel while driving is the alternator putting out that kind of voltage? What type wiring is between the aux and the main? Is the parallel ground to the chassis or back to the main battery negative terminal? (should not be to /thru the chassis!)

Anyway, this is why I use a smart-solenoid. It allows the start battery to be topped off and then charges the aux. even then the deep cycling of my aux means I'm replacing it every two years. My fridge takes it down to 11.1 pretty regularly and if I don't charge it pretty quick, then it starts to get similar symptoms.

 

[Ducky's Dad]

Not real clear on the details of your installation, but the culprit may be a bad or failing starter battery draining the Optima Yellow until you disconnect it from parallel. You can probably recondition the OY and you don't require an Optima charger to do that. The Optima chargers are fine if you can get one, but you can get similar results from an Optimate or a Ctek or maybe even a Noco charger/conditioner. Have both batteries load tested to get a read on actual condition.

 

[ofmountainsandbeaches]

How was the yellow top being charged before this episode?

...

If you run in parallel while driving is the alternator putting out that kind of voltage? What type wiring is between the aux and the main? Is the parallel ground to the chassis or back to the main battery negative terminal? (should not be to /thru the chassis!)

Anyway, this is why I use a smart-solenoid. It allows the start battery to be topped off and then charges the aux. even then the deep cycling of my aux means I'm replacing it every two years. My fridge takes it down to 11.1 pretty regularly and if I don't charge it pretty quick, then it starts to get similar symptoms.

That's how I originally hooked up the Yellow Top. We would drive 6-8 hours a day and it would be fully charged.. but at night the starter battery would deplete it. Over the past 3-4 months it could drain it faster and faster. Sure it would not get charged up perfectly each time, but often it would be topped up fully.

The AUX battery is hooked up to my chassis. I didn't even think of this!! Will run a wire when I have both batteries out for the charge and load test. The red cable is 2 or 4 gauge. I can't recall.. but it is 12 feet long or so.. Sounds like I need to put a smart solenoid in.

Not real clear on the details of your installation, but the culprit may be a bad or failing starter battery draining the Optima Yellow until you disconnect it from parallel. You can probably recondition the OY and you don't require an Optima charger to do that. The Optima chargers are fine if you can get one, but you can get similar results from an Optimate or a Ctek or maybe even a Noco charger/conditioner. Have both batteries load tested to get a read on actual condition.

Thanks Duck's Dad! I doubt I'll be able to locate an optima charger down here, but having a little variety should help me locate one!


Will let you know if I can recover this Yellow Top. Thanks again!

 

[Chris Boyd]

The whole point of the smart solenoid is to cut the link when one of the two battery voltages drop lower than the thresholds. In this case, it would have protected the aux getting drained by what sounds like a weak starter battery. You're almost there, you just need the solenoid itself on the positive and an monitoring panel if you want that. Get a similar gauge wire for the negative battery to battery and don't use the chassis.

Good luck!

 

[Ducky's Dad]

I doubt I'll be able to locate an optima charger down here, but having a little variety should help me locate one!

Ctek may be the easiest to get. I have gotten good results on old OYs with both Ctek and Optimate. I prefer the Ctek.

If the starting battery is draining the OY, then the OY is probably sulphated from being consistently undercharged. If that is the case, a good AGM charger should restore most of its capacity. But, you still need to fix the problem, whatever it turns out to be. I am not a fan of smart solenoids or automatic charging relays because I prefer to switch things myself. You just have to remember to switch things. My solenoid is operated from a dash toggle and my batteries are always isolated when the ignition is off, no matter how the switch is set.

 

[dmilamj]

Get a similar gauge wire for the negative battery to battery and don't use the chassis.

Can anyone elaborate on why the chassis is not appropriate for the battery to battery ground connection?

 

[4x4junkie]

Can anyone elaborate on why the chassis is not appropriate for the battery to battery ground connection?

Steel indeed is a poorer conductor than copper, however the sheer mass of the frame usually more than offsets the poorer conductivity.

The poor conductivity however creates another possible issue: resistance & heating of the frame where you make your connection. To effectively make a high-current connection to a steel frame you have to use a copper plate with several bolts through it to spread the current out so that you don't have a high concentration of current at a single point. Many people probably don't think to do this, so it can lead to issues with burnt-up connections.

Probably the biggest potential issue though is the frame & body of a vehicle is often grounded to the battery (or engine block) with just a #10 or #12 wire or two. With enough current you can burn up these wires as well, and then all hell will break loose.

Certainly it is possible to overcome these issues (I have successfully done so on mine, I have the batteries mounted under the rear floor and the return path is through the frame), however any missed details has a potential to cause big headaches when a high amount of current gets involved. I would only recommend using the chassis of a vehicle as a ground return if someone has a good understanding of what preparations are required to safely do so.

So in the OP's case this could very well be at least part of the problem if no other preparations were done. Quick & easy remedy is like Chris said and run another (ground) cable from the aux battery back to the main battery (-) terminal, and then go from there.
Since the battery isn't too old, chances are good it can be revived with the right charging methods applied to it (something with a desulfation cycle will likely be needed), however the comment about corrosion & water marks on it has me concerned it was being overcharged at some point (check that your alternator voltage is between 14.2-14.6 V after the engine is fully warmed up).

 

[ofmountainsandbeaches]

The saga continues..

Still in Antigua, Guatemala and no closer to getting the Battery charged up with a charger equipped with a desulfator setting. I think I have one found but need to travel into Guatemala City just to see if they(La Casa De La Baterias) have one in stock because they don't want to reply to my emails..

While, I'm waiting/praying they respond with good news. I think I have a 'solenoid' solution as special parts in this part of the world are scarce.. even just a simple switch rated for over 100AMPs seems to be non-existent.

Moving forward, the Isolator I have is the Blue Sea 7610 ACR SI. It has an option to isolate the batteries during engine cranking by simply hooking up 1 wire to the starter wire. My question is, could I simply wire this SI (Starting Isolator) in through a SPDT relay to anything that has power during engine operation. Meaning when the engine was off the SPDT relay would trick the Blue Sea ACR to think the engine was cranking while the vehicle was off? Thus in turn isolating the batteries like a solenoid?

Does this make sense? ..Or have I been drinking to much river water down here?

 

[DiploStrat]

Stop Thrashing and Get Serious Help!

Does this make sense? ..Or have I been drinking to much river water down here?

First of all, take a deep breath and enjoy Antigua Guatemala; lovely place.

Next stop thrashing! With respect, you don't understand the terminology and risk to spend money for nothing.

All I know on this subject can be found here: https://diplostrat.org/documents/ Get a beer and start reading. None of this is hard, it just gets a bit complex.

First the good news: The Blue Sea ACR is one of the nicest bits of kit out there; you chose well. It is an intelligent relay or solenoid. You don't need to buy anything else. In simplest terms, it reads the voltage on both sides. When it detects a solid voltage of over about 13v, the relay closes and completes the circuit. When it detects that the voltage on either side, that is, the voltage of either battery, drops below 12.7v ("full" charge), it opens and stays open until there is a solid 13v+ on one side or the other. Typically, this 13v comes from your engine alternator charging the starter battery or from your solar or shore charger charging the camper battery. The beauty of this type of set up is that you need do nothing; it just works. You could wire up a start isolation, but most of us don't; there is simply no reason do do so.

Now come the questions:

--What is the charging voltage of your vehicle? If it is not well above 14.2v at 70F/20C, then it will never fully charge most AGM batteries. Period. N.B. Some Japanese vehicles, most famously Toyotas, only charge at 13.9v, too low to keep most AGM batteries happy.

-- What is the charging voltage of your solar array? Again, it must be high enough to bring your camper battery to full charge. And you must keep it on charge long enough to complete the absorb stage. This is typically two-four hours of charge AFTER the battery is fully charged. This basically means that you need to have your solar panel on line every day as soon as you stop driving.

-- How are you determining that your batteries are "fully" charged. If all you have is a voltmeter, then you haven't a clue.

-- What is the gauge of the wire between the positive terminal of your starter battery, the Blue Sea ACR, and the positive terminal of your camper battery? This calculator will help you determine your voltage drop: http://www.calculator.net/voltage-d...ce=15&distanceunit=feet&amperes=100&x=56&y=15 Adjust the values as needed to scope out your situation.

-- Make sure the camper battery is well grounded. You can run a wire all the way to the same ground point as the starter battery but it is generally sufficient to simply ground to the same section of frame - not an odd cross member or fender, or whatever.

So what you you have to test?

-- Alternator output: You need to know the voltage and amperage. If your alternator has died, then it will kill both batteries.

-- Starter Battery: Is it good? Will it hold a charge? If not, replace it.

-- Blue Sea ACR function: Apply >13v. Does it close? Remove voltage, does it open?

Now, if I had to guess, I suspect that you have been chronically undercharging your camper battery. Six to eight hours of driving isn't much, especially if you have been letting the battery run down "for a few days." Remember the 50% rule!

Hopefully some of this is useful. (You will note that my comments track with most of the other comments here.)

 

[DiploStrat]

Useful Links

At first read, this looks very good. http://www.comfortablylost.com/12v-electrical-setup/

Notes:

-- I would have used larger wire, fused at 100A vice 50A - both to limit voltage drop and to flow more amps. On the other hand, he did have some professional help, so he may be fine. He bought his kit from these folks who have an excellent tech page - probably clearer than mine: http://www.fridge-and-solar.net/dual_bat.htm

-- I would have grounded the second battery to the same point as the alternator/starter battery, but what he has done is good.

-- VSR (voltage sensing relay) is just another term for intelligent relay or automatic charge relay and, of course, a relay and a solenoid are the same thing.

To repeat: The first, most important test is to be sure that your alternator is still good. The next is to be sure that your alternator produces a high enough voltage to fully charge your camper battery - e.g. something over 14.2v @ 70F.

Finally, if your alternator is good, but your voltage is below 14v, then this may help: http://www.smartgauge.co.uk/alt_mod.html

Alternatively, if you have a way of getting the pieces, a CTEK SmartPass/D250S combo is another option. It has the advantage of including a solar controller as well. http://smartercharger.com/battery-chargers/#CTEK D250S DUAL (The SmartPass is an intelligent relay, specially designed to work with the D250S, which is a voltage boosting charger.)

Again, I hope some of these comments are useful.

 

[Joe917]

As far as electrical parts go you could try a Marina. Sailboats and overland vehicles have a huge electrical parts cross over.
Marinas are also used to dealing with foreigners.
http://www.noonsite.com/Countries/Guatemala/RioDulce

 

[ofmountainsandbeaches]

So checking it all out, the Blue Sea Isolator seems to be doing it's job by disconnecting the two batteries after the flow of current stops (After a short period) from the alternator to the AUX battey.

I think the issue was is that we had run the battery too low too many times. Even once early in the trip to nil where I had to revive it! At no time did I ever fully charge it up with a proper charger. Only juiced it back up to full voltage with the alternator or solar panel.

Solution, new (Larger!) Optima Blue Top battery and a charger to keep it fully topped up every once in while when we have a campsite with electricity.

Fingers crossed we have no more further problems.

...in the meanwhile, what do I do with my weak Yellow Top?!

 

[DiploStrat]

So checking it all out, the Blue Sea Isolator seems to be doing it's job by disconnecting the two batteries after the flow of current stops (After a short period) from the alternator to the AUX battery.

Not surprising; the Blue Sea ACR is an excellent piece of gear. On my truck with a healthy system the intelligent relay stays closed most of the time, typically only opening after I fire up the microwave. Your camper batteries should hold above 12.7v for a LONG time if your camper loads are minimal.

I think the issue was is that we had run the battery too low too many times.

Almost guaranteed to covert the best lead acid battery into a paper weight. But one reason that you need some form of real battery monitor.

Only juiced it back up to full voltage with the alternator or solar panel.

Your alternator and solar panel are perfectly capable of fully recharging a deep cycle lead acid battery; I do it almost every day. You just have to set them both up properly.

Solution, new (Larger!) Optima Blue Top battery …

A waste of money until you fix your charging system or usage pattern. Until you do this you are simply going to kill a bigger battery. Once your charging system is working properly THEN a new, and perhaps a larger deep cycle battery may be what you need. You need to size your battery to your load

and a charger to keep it fully topped up every once in while when we have a campsite with electricity.

Some comments:

-- A good shore charger is ALWAYS a good idea. Be prepared to use it at least once a week if you don't fix the rest of your system.

-- Remember that most of South America is 220v 50Hz.

Were I thee, I would concentrate on fixing my truck first.

Final comment: I assume that you have read this, that is, the Optima Yellow Top is NOT a deep cycle battery and may not be the best choice for your application: http://www.optimabatteries.com/en-us/support/battery-care/charging/

Safe travels!

 

[Ducky's Dad]

Final comment: I assume that you have read this, that is, the Optima Yellow Top is NOT a deep cycle battery and may not be the best choice for your application: http://www.optimabatteries.com/en-us/support/battery-care/charging/

Well, Optima clearly states that these Yellows are deep cycle batteries. This from the link you posted:

YELLOWTOP® Type: D31A & D31T
These batteries are dual-purpose. They are designed for engine start and deep-cycle applications for use in vehicles with large accessory loads.

Solution, new (Larger!) Optima Blue Top battery and a charger to keep it fully topped up every once in while when we have a campsite with electricity.

Maybe a solution, maybe not. Not all Optima Blues are deep cycle, and their dealers are often confused about the two lines of Blues. Check the Optima website to confirm my memory, but the Blues with dark gray case are starting batteries, electrically and chemically identical to the Red starting batteries. The Blues with the light gray case are dual purpose (starting and deep cycle) and are electrically and chemically identical to the Yellows in the same group size.