# Can I use a battery charger to maintain settings? **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [January 5, 2009, 9:40pm UTC](https://community.cartalk.com/t/can-i-use-a-battery-charger-to-maintain-settings/24440 "2009-01-05T21:40:41Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![brian4xp](https://avatars.discourse-cdn.com/v4/letter/b/a183cd/32.png) [@brian4xp](https://community.cartalk.com/u/brian4xp)\ **Post date:** [January 5, 2009, 9:40pm UTC](https://community.cartalk.com/t/can-i-use-a-battery-charger-to-maintain-settings/24440/1 "2009-01-05T21:40:41Z")
If I need to disconnect the battery terminals to clean them is it OK to use a battery charger connected to the terminals to keep settings from being lost? I do realize I would need to be very careful to avoid shorting anything but will this work? This is a general question but if the car make/model makes any difference I have a 90 Camry and an 2000 Sienna. ---
**Author:** ![brian4xp](https://avatars.discourse-cdn.com/v4/letter/b/a183cd/32.png) [@brian4xp](https://community.cartalk.com/u/brian4xp)\ **Post date:** [January 5, 2009, 9:42pm UTC](https://community.cartalk.com/t/can-i-use-a-battery-charger-to-maintain-settings/24440/2 "2009-01-05T21:42:01Z")
Oh, and I am aware of those devices to plug into the lighter socket but I don’t have one of those and I do have a battery charger. ---
**Author:** ![tardis](https://avatars.discourse-cdn.com/v4/letter/t/f0a364/32.png) [@tardis](https://community.cartalk.com/u/tardis)\ **Post date:** [January 5, 2009, 9:55pm UTC](https://community.cartalk.com/t/can-i-use-a-battery-charger-to-maintain-settings/24440/3 "2009-01-05T21:55:18Z")
Some battery chargers, yes, others, no. Some chargers put out a pretty clean and well controlled DC voltage. This would be okay. Some chargers put out a very chopped and spiky waveform. These might cause damage to some of the electronics. Some chargers have safety circuits to detect backwards connections and such. These would likely shutdown as soon as you disconnected the car battery, and your settings would be lost. The safe answer is a small 12V battery connected to the lighter socket. ---
**Author:** ![brian4xp](https://avatars.discourse-cdn.com/v4/letter/b/a183cd/32.png) [@brian4xp](https://community.cartalk.com/u/brian4xp)\ **Post date:** [January 5, 2009, 10:12pm UTC](https://community.cartalk.com/t/can-i-use-a-battery-charger-to-maintain-settings/24440/4 "2009-01-05T22:12:53Z")
So would this be connected positive terminal to the center connector in the lighter and negative to the sleeve connector? ---
**Author:** ![tardis](https://avatars.discourse-cdn.com/v4/letter/t/f0a364/32.png) [@tardis](https://community.cartalk.com/u/tardis)\ **Post date:** [January 5, 2009, 10:23pm UTC](https://community.cartalk.com/t/can-i-use-a-battery-charger-to-maintain-settings/24440/5 "2009-01-05T22:23:44Z")
Yes ---
**Author:** ![brian4xp](https://avatars.discourse-cdn.com/v4/letter/b/a183cd/32.png) [@brian4xp](https://community.cartalk.com/u/brian4xp)\ **Post date:** [January 5, 2009, 10:37pm UTC](https://community.cartalk.com/t/can-i-use-a-battery-charger-to-maintain-settings/24440/6 "2009-01-05T22:37:59Z")
Thanks. I wouldn’t need to worry about amperage since there shouldn’t be any big drain. Just need to not try to start the car or run accessiories with it plugged in, right? ---
**Author:** ![tardis](https://avatars.discourse-cdn.com/v4/letter/t/f0a364/32.png) [@tardis](https://community.cartalk.com/u/tardis)\ **Post date:** [January 5, 2009, 10:59pm UTC](https://community.cartalk.com/t/can-i-use-a-battery-charger-to-maintain-settings/24440/7 "2009-01-05T22:59:39Z")
Yes. The biggest drain would likely be the dome light. Connect the reserve battery and then shut the door before disconnecting the car battery. You may want to wait up to 30 minutes for all of the electronics to power down, but even if you don’t, the drain should be less than an Amp. ---
**Author:** ![Joseph\_E\_Meehan](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/joseph_e_meehan/32/21_2.png) [@Joseph\_E\_Meehan](https://community.cartalk.com/u/Joseph_E_Meehan)\ **Post date:** [January 6, 2009, 2:32am UTC](https://community.cartalk.com/t/can-i-use-a-battery-charger-to-maintain-settings/24440/8 "2009-01-06T02:32:32Z")
The make little devices to plug in the lighter (Power Center) that will keep, I believe 9 volts on it and that usually takes car of the settings. A charger is iffy. It may work, it may damage something.