Portable battery tender
Thread Starter
Burning Brakes
Joined: Mar 2010
Posts: 921
Likes: 134
From: Chicago Illinois
Portable battery tender
Hey Guys,
My brother in law added some led lights to his CCA under hood dress up kit. Last car show he had them on for quite a while. His car needed a jump to start
Is there a lightweight portable unit that could be plugged into the port in the trunk to keep the battery’s charge levels up? Keeping in mind he can’t use a regular battery tender at the shows because no electrical outlets.
First world problems…I know. lol
Les
My brother in law added some led lights to his CCA under hood dress up kit. Last car show he had them on for quite a while. His car needed a jump to start
Is there a lightweight portable unit that could be plugged into the port in the trunk to keep the battery’s charge levels up? Keeping in mind he can’t use a regular battery tender at the shows because no electrical outlets.
First world problems…I know. lol
Les
Instructor
Joined: May 2019
Posts: 243
Likes: 189
From: South East Wisconsin
Maybe power the LEDs with a separate power source just for shows? You would need to know the power draw and length of time to make a reasonable choice of power brick.
https://www.harborfreight.com/450-pe...hoCF80QAvD_BwE
https://www.harborfreight.com/450-pe...hoCF80QAvD_BwE
Race Director
Joined: Aug 2015
Posts: 12,247
Likes: 4,740
From: SE WI
Not sure a jump brick would have enough capacity as per the questions stated above. The one in the link above is 12AH which is about 1/6 the capacity of your car battery. Connecting it in parallel with the one in the car, I'm not sure which one would draw down faster. Depends on each battery's internal impedance. You might end up with the brick getting completely discharged and some of the car battery too. The other solution, which is not compact, is to buy a small inverter and another car battery (or small motorcycle battery). Use that to power a battery tender. The tender and battery would have to have enough continuous amps to charge the car and power the lights for that entire time period.
Instructor
Joined: May 2019
Posts: 243
Likes: 189
From: South East Wisconsin
If the LED kit is 15 watts, the 12AH brick would power the lights for almost 10 hours if connected directly. That would be the best choice for extended run time.
Paralleling to the battery is not a good idea. Both will run down. Using a separate battery and inverter to power a tender is just way too inefficient and complex. The OP would be better off letting the car battery die and use a jump pack to get it running again.
Paralleling to the battery is not a good idea. Both will run down. Using a separate battery and inverter to power a tender is just way too inefficient and complex. The OP would be better off letting the car battery die and use a jump pack to get it running again.
