[txbonds]

Either the wrong sized battery, a bad battery, or even a failing alternator could cause the low voltage problems. Other things could be if you have some sort of other problem going on that is draining the battery power, like an improperly installed accessory that's been added.

Have someone confirm the battery size is correct, and also test the alternator output, at least that's where I"d probably start. That and making sure that your power and ground wires on the battery and to the alternator are in good shape and making a good solid connection.