You should be able to leave it on there for years.
When the battery is showing the correct no-load voltage, 13.8V or so, it's charged.
I didn't think they still made completely sealed batteries any more! Most of the "maintenance free" batteries still have open cells so you can check with a hydrometer.
It would take a long time to overcharge it. In the vehicle, the battery is being subjected to a 14.5 (approximately) charging voltage the whole time the vehicle is running, and some vehicles almost never shut down. A battery is capable of 12.9 to 13.2 volts (depending on electrolyte specs) so the 1.3 to 1.6 volt differential across an internal resistance of less than one ohm will give a charging current of more than one amp, without any damage. Many of the newer sealed batteries are the recombinant-gas type, and have devices within them to convert the gases given off back to electrolyte so that there's no loss of liquid worth worrying about. They have a pressure-release for safety, but they're otherwise sealed up tight. Older "sealed" batteries had flat, ganged cell caps that can be easily pried off to replenish the cells. Lots of those still being sold.
Can anyone give me a rough idea how long I can leave a 1 amp charger on a partly discharged car battery without risking overcharging? I have a VOM that I know how to use, how should I check to determine when max. charge has been obtained?
Is there anyway to check the electrolyte level on the newer sealed batteries to insure it is not too low, or is this not advisable?
That's what I thought at one time but I was wrong! I bought a new HD group 27 batteryand put it on a hand truck with cables attached to use for jump starts. I bought a 1/2 amp $6 charger and left it plugged in whenever the jump cart was not in use thinking the charge was so slow it couldn't hurt the battery. In 6 months the battery was bone dry and wasted. The cheap charger had no "intelligence" to shut down when charge was complete.. While capable of only small current, it was not voltage-limited and gradually the voltage escalated amd depleted the water. When I discovered what I had done the little shitbox was putting almost 16 volts across my trashed battery.
Don in Austin
formatting link
Yes if they are any good. If they are really cheap perhaps not.
A "trickle charger" is one where the charge rate is so low the charge rated does not NEED to be reduced, because the thermal balance would be in equilibrium at that rate (no excessive heating). Now, some fast chargers do have a trickle MODE, where they sense the battery is charged and go to a trickle mode, but a pure trickle charger has one charge rate, the rate at which it can charge the battery indefinitely without harm.
I think a battery tender/charger (I don't own one, but I do own a few old 6 volt/12 volt battery chargers) is a good idea.They are available in different models and prices.
formatting link
or visit some auto and marine supply stores and see what they have for sale. cuhulin
Yes, the voltage of the battery with everything disconnected and after a rest of about 15 minutes should be no more that 12.8 volts DC. The charging voltage should never exceed
14.2 volts for more than a few seconds, it can cause the battery plates to warp.
Yes, but each brand has different ways of sealing the vents. Try Googleing the brand or just take a close look at the top. I would suggest you find a junk battery that has the same top as yours and playing with it, but be careful a junk battery may still have a lot of amps left and there is still acid in them.
***************** Thank You snipped-for-privacy@msbx.net
To reply to this email please remove the AT after the kGb in the reply to address as shown above.
One of those glass tube thingys with the squeeze bulb (I forget what they are called) thingy and the little ''plastic'' balls in the tube.(Hydrometer?) cuhulin
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.