I strongly recommend against this idea, for the following reason: Once you fully discharge the 7 AH battery, the 18 AH battery still has half of full charge, and will continue to deliver current through the discharged battery; this will, in effect, reverse-charge it. The effect is similar to connecting a low-current charger with reversed polarity to the smaller battery (though without the explosions, as a charger has a much higher peak current). This will probably damage or destroy the smaller battery.
If you try to charge the series combination, you may well wind up either overcharging the smaller battery or undercharging the larger one, which won't do much good for either one. Of course, if you're *very* careful to never draw the 7 AH pack down all the way, and if you charge the batteries separately, you can probably avoid these scenarios, but it's a chancy thing, and the temptation to get in just one more run when the battery is low will probably bite you. Regards, Steve On Jan 24, 12:13 am, Enzo Salas <[email protected]> wrote: > Hi, > > Is it possible to series 1 pc 12volt 18 AH SLA battery and 1 pc 12volt > 7AH SLA bat? > > I want to produce 24 volts with the least battery weight.. > > Regards, > Enzo -- You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to [email protected] To unsubscribe, send email to [email protected] Visit the group at http://groups.google.com/group/rctankcombat
