dual batts, 4 people who know

[knukonceptz 10+ year member]

I personally have used mixed type batteries together without an issue. Had a Interstate Wet battery under the hood and 4 SVR audio Batteries in the rear, never had a problem with anything draining another. They were however SIMILAR in OUTPUT. Again HOW EXACTLY did you determine one is draining another?

Isolators are not a good option for audio systems

And they can be of different age, BUT they have to be GOOD and CHARGED (what a concept, I know...)

 

[MustangGT25YRS 10+ year member]

Hello,

I've heard that *Solenoids* are suppose to be Better than Isolators,because it doesn't drain on the Main Battery,and will not cause a Voltage Loss.

When you have the key in the Accessory Position,it only takes the Juice from the Stereo Battery(ies) for Key/Off listening.*KNU*...Could you please let me know if this is Correct?Take Care.

Kind Regards/

 

[scottiej 10+ year member]

Chances are your front batt is just getting old, but there could be several reasons for your problems. If your car's / stereo's current requirements are more than what your alternator can provide, then when the alt is spinning it's putting all of it's current into your accessories (amps,xovers,monitors, etc.) and not your batts. Another scenario would be if your alt is big enough to charge both batts, and provide enough amps for your system, then the new big batt could be absorbing all the charge. AGM batteries typically have a higher CEF (Charge Effeciency Factor) and will accept a charge more readily than a flooded battery. Over time, the front battery will be starved for current, unless you have periods of low current demand, which would give the front batt a chance to get "caught up". My suggestion... charge both batteries to 100% and re-install them... see what happens. If it starts acting up again you can do one of two things... get an isolator, or a new battery.