Alternator overcharging batteries
I have 4 AGM batteries in my rig with a total capacity of 440AH (actually 880AH @ 6V, but of course they are wired to get 12V). The data sheet for my Haze batteries species a bulk -> absorption cut...
Forum Discussion
Alternators can have internal voltage regulators, or external. It is vehicle/ platform dependent. What vehicle do you have? alternator? Mexwanderer knows his alternators.
My '120 amp alternator' maxes 62 amps at 800rpm cold, and 32 amps max hot at 525 rpm and I have seen it touch briefly on 110 amps into my depleted battery
Their output varies greatly, the alternator rating established in a lab, when cold, at high rpm with large loads and a circuit capable of passing huge current.
Voltage when driving will be changing with rpm and battery state of charge, and the decisions of the voltage regulator, which can be as loony as a meth addict.
AGM batteries enjoy high recharge rates, even those which say to limit charging amps to 30 per 100AH of capacity.
Low and slow Solar alone and deeply cycle agms do not make for happy long lived AGM's. They need the occasional high amp recharge from their most depleted state. For best AGM battery life on a deeply cycled battery, this is not optional.
Just because your solar charge controller drops to float voltage, does not mean the batteries are fully charged. It only means they attained absorption voltage and held it as long as programed to do so.
proper absorption voltage and duration are moving targets. A one size fits all charge algorithm is more a one size fits none
With AGM's, full charge can be determined by the amount of amps they can accept at absorption voltage.
Lifeline, topdog AGM maker, says when a 100AH battery can only accept 0.5 amps at 14.4v, only then it can be considered fully charged.
Do not believe blinking green lights that supposedly indicate a fully charged battery. They are insane and mock any human who believes them when they first alight on a deeply cycled battery.
Just because lots of people have faith in blinking green lights, does not make them right, no matter how vocal they might be/become, when their faith is questioned.
Trust if you want, but I prefer to verify.
My '120 amp alternator' maxes 62 amps at 800rpm cold, and 32 amps max hot at 525 rpm and I have seen it touch briefly on 110 amps into my depleted battery
Their output varies greatly, the alternator rating established in a lab, when cold, at high rpm with large loads and a circuit capable of passing huge current.
Voltage when driving will be changing with rpm and battery state of charge, and the decisions of the voltage regulator, which can be as loony as a meth addict.
AGM batteries enjoy high recharge rates, even those which say to limit charging amps to 30 per 100AH of capacity.
Low and slow Solar alone and deeply cycle agms do not make for happy long lived AGM's. They need the occasional high amp recharge from their most depleted state. For best AGM battery life on a deeply cycled battery, this is not optional.
Just because your solar charge controller drops to float voltage, does not mean the batteries are fully charged. It only means they attained absorption voltage and held it as long as programed to do so.
proper absorption voltage and duration are moving targets. A one size fits all charge algorithm is more a one size fits none
With AGM's, full charge can be determined by the amount of amps they can accept at absorption voltage.
Lifeline, topdog AGM maker, says when a 100AH battery can only accept 0.5 amps at 14.4v, only then it can be considered fully charged.
Do not believe blinking green lights that supposedly indicate a fully charged battery. They are insane and mock any human who believes them when they first alight on a deeply cycled battery.
Just because lots of people have faith in blinking green lights, does not make them right, no matter how vocal they might be/become, when their faith is questioned.
Trust if you want, but I prefer to verify.
