- Connecting different batteries in parallel is OK, but generally not ideal due to potential over/under charging issues when not properly handled.
We're talking about automotive here. The voltage regulator pushes the bus voltage to a set point and the batteries absorb what they can at that voltage. Constant voltage charging. You can parallel any combination you want in that situation.
The only potential issue is if the voltage regulator's set point is too high (for gel type batteries, many voltage regulators are set too high) or too low (some voltage regulators are set too low for some types of agm...like Odyssey TPPL or Optima spiral wound).
Different types, sizes, ages etc., which is important for a full time bank, is irrelevant in this situation.
- Connecting flooded (his starter battery is most likely a regular flooded cell battery since he didn't mention it was not) and AGM batteries in parallel are not a good idea.
Again, irrelevant in this situation.
- His solar power system is not capable of properly charging his battery bank.
A) It's only a bank when the voltage rises high enough to trip the solenoid and tie the batteries. Normally, in that situation, the engine battery would already be 99.99% charged, and the house battery would have bulked to 80% or more. So...
B) His solar is certainly capable of fully charging his battery/bank.
Whether it bulks/absorbs at high enough voltage to get it done in a timely fashion is another issue.
For the first point: if you connect 2 batteries of the same type (flooded/AGM/gel) but differently sized in parallel, over time the batteries will die if they are not properly and fully charged all the time.
All batteries will die if not properly and fully charged.
You are applying the rules for a full time bank to a part time "while charging only" bank.
Apples and oranges.
Second point: Flooded cell (your regular lead acid starter battery) and AGM (Optima Yellow Top) have different charging curves and characteristics,
Again, irrelevant. Unless there is some sort of programmable computer controlled voltage regolator in this guy's Delica, it doesn't do charging profiles anyway. It's just a dumb constant voltage charging system.
charging them in parallel from one source will kill one of the batteries over time (AGM can't handle the flooded charging voltage, flooded has some issues with the AGM charging as well I think).
Nah. First of all, again it's just a constant voltage charger with no idea what kind of battery is hooked up to it.
Second, "charging voltage" is not a precise thing. It's just a chemistry experiment in a plastic box. Get it up to a high enough voltage to overcome the resistance and hold it there long enough, and the chemistry will absorb all the electrons it can.
The goal is to go as high as possible without overheating the experiment. No charging system that doesn't have temperature compensation can ever really hit the precisely correct "charging voltage".
Third, except for a few oddballs, agms and floodeds all use pretty much the same charge profiles.
Third point: In this case I think the solar system might be able to provide just enough power to keep the Blue Sea ACR connected but not enough to charge the system thus also having the starter battery drained.
Um. Unlikely for a couple reasons. 150w, even flat mount with a PWM controller on a cloudy day should be putting out 5a. Pretty sure the ACR only draws an amp or so.
More importantly, the ACR won't tie the batteries until the house battery reaches 13.2v. With the cranking battery resting at 12.8, and the house battery at 13.2, even once they are tied, the house battery is not going to drain the engine battery.
When using solar, make sure the ACR is disconnected and your starter battery should stay charged.
That should not be necessary if the ACR is working properly (it's a Blue Sea...has anyone ever heard of a Blue Sea ACR failing?) and if the batteries are not fried (his batteries are fried).
Also as a rule of thumb: If your car didn't come with an AGM battery from the manufacturer, the alternator probably is not capable of properly charging AGM batteries.
That just depends on what the voltage regulator is set to.
My 40 y.o. Ford campervan holds 14.5v at any RPM above idle. Since it doesn't have temperature compensation, and I spend a lot of time in the desert, I'm quite certain this thing could potentially cook any 12v battery on the market today.
Fortunately, I don't fly my van in "unusual attitudes", so I don't need sealed batteries and can monitor the water levels.
My 67 VW Bug with a generator also had a voltage regulator set to 14.5v.
Diplostrat said something about Yotas being known for having 13.9v regulators? I have no idea, but it wouldn't surprise me. Of course, 13.9v is not too low for an agm...it's just too low period.
I would recommend replacing the dead batteries for new ones
Absolutely. Using that blown yellow top for a cranking battery is just a bad idea on general principles.
And the blue top was dodgy to begin with. Sitting around at 12.3v (<75% charged) for who knows how long, it was beyond any doubt somewhat sulphated when he bought it.
And is anyone sure they sold him the deep cycle blue top and not the cranking version?
(you might be able to revive them, but if it requires buying equipment and spending money, the batteries probably won't get their old capacity back) and changing the Blue Sea ACR for a DC-DC charger like the Ctek D250S (with smartpass if you want to be able to jump start using the house battery) already mentioned in this topic.
I like the Ctek 250. But really, I think he's fine with what he's got if he just gets it working properly with a decent set of batteries. AND doesn't abuse the batteries to death.
