kijana
Free Member
Our RV has a whole locker full of leisure batteries. We carry two 120 a/h + one 90a/h standard lead acid batteries, giving us 330 a/h in total. I'm told I'm not supposed to mix batteries of different capacity, as the smallest does all the work, but I had a nearly new 90a/h battery lying about so wired it in anyway.
Despite such capacity, we have exhausted the batteries during prolonged spells of wildcamping, since we're reluctant to run our huge genny & don't have solar panels (yet).
So when I come to replace the leisure batteries, which can't be far off now, which type should I use?
There appears to be a fundamental problem with leisure batteries, since there are conflicting service conditions.
There are three broad types avaialble: 1) 'ordinary' lead acid car type batteries; 2) deep cycle wet batteries 3) sealed gel batteries. All of these types are designed to satisfy different requirements.
Type 1) is found in cars as starter batteries. They like to sit there all day long, being charged by the alternator constantly, so they stay at the same voltage all the time. Every morning & evening, & maybe a couple of times in between, they have to provide high starting currents to get the donkey running, but only for a few seconds. Since alternators provide high current at low rpm, the battery never has to do much so will last a long time under these conditions.
Type 2) like to be charged fully, then discharged down to 10 or 10.5 volts, then charged back up again. They don't have a problem with this, unlike type 1) which will only take a few cycles and then give up. What deep cycle batteries don't like is being kept at a constant voltage by trickle charging.
Type 3). I don't know what these batteries like. I do know Trinity House use them to power remote lightouses, where a bank of gel batteries is charged by solar panels over summer, and keeps the light powered up over winter.
So now let's look at what I want from my leisure batteries. I spend most of my time either on hookup in aires or campsites, or driving around (when the batteries will be under charge from the alternator). Occasionally, I wildcamp, maybe for a few days, when the batteries will fully discharge.
So type 1) will hate being fully discharged when I'm wildcamping.
Type 2) will hate being kept at a constant voltage when I'm not wildcamping.
Type 3) I don't know about.
So what do I buy when my current set give up?
TIA
Bruce
Despite such capacity, we have exhausted the batteries during prolonged spells of wildcamping, since we're reluctant to run our huge genny & don't have solar panels (yet).
So when I come to replace the leisure batteries, which can't be far off now, which type should I use?
There appears to be a fundamental problem with leisure batteries, since there are conflicting service conditions.
There are three broad types avaialble: 1) 'ordinary' lead acid car type batteries; 2) deep cycle wet batteries 3) sealed gel batteries. All of these types are designed to satisfy different requirements.
Type 1) is found in cars as starter batteries. They like to sit there all day long, being charged by the alternator constantly, so they stay at the same voltage all the time. Every morning & evening, & maybe a couple of times in between, they have to provide high starting currents to get the donkey running, but only for a few seconds. Since alternators provide high current at low rpm, the battery never has to do much so will last a long time under these conditions.
Type 2) like to be charged fully, then discharged down to 10 or 10.5 volts, then charged back up again. They don't have a problem with this, unlike type 1) which will only take a few cycles and then give up. What deep cycle batteries don't like is being kept at a constant voltage by trickle charging.
Type 3). I don't know what these batteries like. I do know Trinity House use them to power remote lightouses, where a bank of gel batteries is charged by solar panels over summer, and keeps the light powered up over winter.
So now let's look at what I want from my leisure batteries. I spend most of my time either on hookup in aires or campsites, or driving around (when the batteries will be under charge from the alternator). Occasionally, I wildcamp, maybe for a few days, when the batteries will fully discharge.
So type 1) will hate being fully discharged when I'm wildcamping.
Type 2) will hate being kept at a constant voltage when I'm not wildcamping.
Type 3) I don't know about.
So what do I buy when my current set give up?
TIA
Bruce
