Charging single 8 volt battery?

[jsalpha2]

My charger has switch for 6v and 12v. Can I put a capacitor in-line or something to make it charge at 8V? Wanting to charge 8v golf cart batteries one at a time.

 

[RLGL]

Google is your friend! A proper charger can be found at Amazon.com as well as other sites.

 

[C1]

http://www.rvforum.net/SMF_forum/index.php?topic=53157.0

 

[mindless1]

No to the capacitor, not that simple. There may be some modification you can do to your present charger depending on its design.

For example if it has a feedback loop that detects the voltage you can pull that up towards the positive power rail to make the charger think the battery is at 12.6V (or above if it float charges) when at 8.4V.

If it has no feedback, just a crude old pair of transformer windings to determine 6V vs 12V, you might try putting 6 silicon diodes in series. The typical drop @ current will be around 0.7V each so a series of 6 will be about 4.2V, near the difference between an 8.4V and 12.6V battery. It may take some fine tuning to make sure the battery gets topped off without overcharging.

Otherwise you can build your own regulation circuit, a stand alone or in series with the battery charger, or of course buy a ready made charger for 8V, which I suspect will be both the easiest and most expensive route.

Frankly if I had leftover 8V golf cart batteries I would just sell them and get 12V or 6V, design whatever you're doing around batteries that are both more common and less expensive.

If you're just needing to add a new battery to a series in a golf cart, just use your charger set to 12V and terminate it manually when you see the battery near 8.4V with the charger disconnected, then use in the golf cart and charge normally with the rest the next time.