I’ve been keeping the lead-acid starter battery on a pick-up truck that I use infrequently charged with a charger on a timer for years (1 hour per day). I typically get 7 years plus out of my batteries. I suppose could use a maintainer but I got started with a charger on a timer many years ago and it has never failed me. It always seemed that letting the battery slightly discharge and recharge every day might actually be a good thing. I use a maintenance-free lead-acid battery and have never seen a problem. And the idea of a 1/24 duty cycle for charging seemed appealing. I suspect this strategy which Mike also described would work great with an RV in storage too. One alternative suggestion is to use a smart plug rather than a mechanical timer. Although they cost a few bucks more, Smart plugs can be programmed with an app which allows great flexibility and remote control as long as there is WiFi access at the storage location. Plus there are no moving parts so they should last longer. I realize there may not be WiFi access in RV storage lots but a smart plug should continue to work once set-up. Mike, it might be an interesting to compare the use of charger on a timer to a maintainer to see the pros and cons of each strategy. A side by side comparison experiment run for the life of the battery would be great but would take too long unless there was a way to stress the system with a load on the battery to make it fail earlier. Food for thought.
I am using a BatteryMINDer Model 2012 on a pair of 6 volts batteries, connected in series. I store and keep them in my garage and keep them on the charger all winter. Except for the checking fluid levels, I thought this was "set and forget" . Am I wrong? Am I damaging my batteries by leaving them on my BatteryMINDer, 24/7 for 6 months?
A Battery Minder (or Tender or Float Charger" is an intelligent charger that monitors the battery's SoC (State of Charge) and only adds as much makeup current as needed. So you're doing the right thing for best battery life.
But standard 2-stage chargers that go into trickle-charge mode keep charging the battery once it's at 100% SoC, and that's what can boil out the electrolyte.
On the other hand, Lithium batteries have an internal BMS (Battery Monitor System) that regulates charging current, just like your smart phone does while plugged into a wall charger.
I like this idea but with one caution. Make sure your timer is rated for the amp draw. I have seen timers short out because the amp draw was more than the switching system could handle when cycling on a regular basis.
I’ve been keeping the lead-acid starter battery on a pick-up truck that I use infrequently charged with a charger on a timer for years (1 hour per day). I typically get 7 years plus out of my batteries. I suppose could use a maintainer but I got started with a charger on a timer many years ago and it has never failed me. It always seemed that letting the battery slightly discharge and recharge every day might actually be a good thing. I use a maintenance-free lead-acid battery and have never seen a problem. And the idea of a 1/24 duty cycle for charging seemed appealing. I suspect this strategy which Mike also described would work great with an RV in storage too. One alternative suggestion is to use a smart plug rather than a mechanical timer. Although they cost a few bucks more, Smart plugs can be programmed with an app which allows great flexibility and remote control as long as there is WiFi access at the storage location. Plus there are no moving parts so they should last longer. I realize there may not be WiFi access in RV storage lots but a smart plug should continue to work once set-up. Mike, it might be an interesting to compare the use of charger on a timer to a maintainer to see the pros and cons of each strategy. A side by side comparison experiment run for the life of the battery would be great but would take too long unless there was a way to stress the system with a load on the battery to make it fail earlier. Food for thought.
I am using a BatteryMINDer Model 2012 on a pair of 6 volts batteries, connected in series. I store and keep them in my garage and keep them on the charger all winter. Except for the checking fluid levels, I thought this was "set and forget" . Am I wrong? Am I damaging my batteries by leaving them on my BatteryMINDer, 24/7 for 6 months?
A Battery Minder (or Tender or Float Charger" is an intelligent charger that monitors the battery's SoC (State of Charge) and only adds as much makeup current as needed. So you're doing the right thing for best battery life.
But standard 2-stage chargers that go into trickle-charge mode keep charging the battery once it's at 100% SoC, and that's what can boil out the electrolyte.
On the other hand, Lithium batteries have an internal BMS (Battery Monitor System) that regulates charging current, just like your smart phone does while plugged into a wall charger.
A fully charged FLA battery has a freezing point below -80°F (-62°C), while a discharged battery has a freezing point of 20°F (-6.7°C) or higher.
We never get to -20F and we keep the FLA batteries above 90% SOC… if it ever gets to -80F here the batteries are the least of our problems…
I like this idea but with one caution. Make sure your timer is rated for the amp draw. I have seen timers short out because the amp draw was more than the switching system could handle when cycling on a regular basis.
Also what is your opinion of float chargers?
Note that the timer that we linked to is rated for 15 amperes of current.
And as I’ve recently posted, I think that float/tender chargers are the best option for long-term storage.