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Discussion Starter #1
I'm using my battery tender now sporadically (because my car is stored outdoors and I can't leave the hood unlatched 24x7 while I'm away). I'm seeing some interesting results from the tender and I'm not sure how to interpret it. I'm using a Duracell battery maintainer (SLC10002) and when I plug it in, I have it set properly to charge at 12V. Upon first charging the tender reports the battery at 25%. The charger can take it all the way up to 100% given enough time. However, it seems that once I remove the tender and let the car sit for several hours, it drops back down to 25%. I've seen this several times and do not understand. The car can't possibly discharge itself 75% in just a few hours. It would be dead in a day if that were the case. My car sat for 14 days when I first hooked up the charger and it read 25%. Temps are hovering between 0-4 degrees C (32-40F). That's not particularly cold so I dont know why the battery would drop 75% from full charge so fast. I assume the battery tender can accurately read the condition of the battery, but maybe that's a false assumption.

Thank you for your advice.
 

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I wouldn't put much trust in the accuracy of the display on the battery tender. Mine does the same thing - it always says"low" when I first plug it in.

I installed my battery tender permanently in the trunk so I could charge the battery without having the trunk open. I and ran the wires out just above the rear license plate. There's a hole there (I assume it's a drain hole) big enough to run the wires through. I had to cut the wall plug off and splice the wires back together after I ran the wires through the hole. When I'm driving, I just stuff the wire and plug up into the cavity above the license plate.
 

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Discussion Starter #3
I wouldn't put much trust in the accuracy of the display on the battery tender. Mine does the same thing - it always says"low" when I first plug it in.

I installed my battery tender permanently in the trunk so I could charge the battery without having the trunk open. I and ran the wires out just above the rear license plate. There's a hole there (I assume it's a drain hole) big enough to run the wires through. I had to cut the wall plug off and splice the wires back together after I ran the wires through the hole. When I'm driving, I just stuff the wire and plug up into the cavity above the license plate.
Thanks for the feedback and the idea on ways to keep the trunk closed. Much appreciated.
 

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Same here. My tender would be at 100% and I could unplug and plug it back in and show me ~50% charge. My guess it takes some time to accurately show the real charge.
 

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Discussion Starter #5
Same here. My tender would be at 100% and I could unplug and plug it back in and show me ~50% charge. My guess it takes some time to accurately show the real charge.
Good to know, thank you. I can't use my tender every day so I was worried that the battery might drop to 0 between charging sessions. Once weekly (all day) would be a schedule I could maintain fairly well.
 

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just on the side - you could run the battery tender wire through the passenger side intake and into the engine bay - so this way you can close and lock the engine lid.
 

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I know that there have been threads about installing a magnetically attached tender at the top of the Elise license plate, but I cannot find the threads on the new web site. I did this, and it works great!
 

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Discussion Starter #8
just on the side - you could run the battery tender wire through the passenger side intake and into the engine bay - so this way you can close and lock the engine lid.
Thank you for the suggestion. I'll see if my extension chord can snake its way into the car via that route. That would be nice. Right now I give the car 5-10 hours of charging per week spread out over 3-4 days. It seems to work OK with the tender reporting full charge if kept on 5 hours at a time. I'd rather just keep it on all the time if possible to will see if I can get the extension chord up and into the car as you suggest. Thanks again.
 

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Magnetic Trickle Charger Connector

 
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