How often should i charge a lead acid battery?

[chris414]

I'm working on a project that involves some wheelchair motors and two 12Volt lead acid batteries. I've heard that the surest way to ruin your batteries is to run them dead and then leave them uncharged... Since I'm very much still in the testing phase, I was wondering when I should be recharging my batteries. I'm highly unlikely to run them even half way down (I probably use about 5 or 10% of the batteries' charge a day), so when should I be recharging them? At the end of every day, or should I wait for them to discharge further?

 

[Boncuk]

Hi Chris,

an lead-acid-battery should not be discharged lower than 1.8V per cell.

That means it must be charged if the total voltage has dropped below 10.8V.

Some chargers start charging at 10.5V, but I don't think that would not be good for a wheel chair battery, since it has to supply full power throughout the day.

A fully charged battery has 2.4V per cell (14.4V total). So there is plenty to play with.

Boncuk

 

[Sceadwian]

chris, lead acid batteries last longest when kept fully charged, so the best thing to do is leave them on a float charger anytime it's not in use, if you can determine the charge state of the battery it's best to turn the charger off once it's full and then just periodically turn it on to top it off if it's sitting idle for a long period of time. Car batteries for example are constantly float charged by the alternator anytime the engine is running, though more modern cars may stop float charging if the car is running for long period of time as it's not a good idea to continously charge a completly full battery or gasing occurs.