How can I troubleshoot a drain in the 12v system?

can u paste a ling of a battery charger? good but not really expensive, do u thing advance autoparts sell them?

 

Hmmmm. Good but not cheap? That depends on your definition of cheap.

A decent smart charger will run in the area of $75 and up. The charger I use is $130

CTEK makes decent smart chargers. You can do a google search and find them easily. Look on Amazon. You could probably find something at Advanced, but I don't know what the quality would be like.

A good smart charger will have at least 3 steps in the charging setup 5 steps is better. Also a good smart charger will have settings for both AGM, Gel, and Flooded Type Batteries. Also a good smart charger will have a desulfate mode in the process.

I use a batteryminder 12248.



Other's here on PC use it as well as the CTEK chargers.

CTEK Battery Charger=

Take some time to google the thing and learn about it. It is a investment that will pay for itself over time. Don't cheap out on a charger. You can do more damage than good if you use a cheap battery charger.

 

Autocraft 1/12/75 Amp 12-Volt Automatic Battery Charger/Maintainer SE-1275A: Upgrade with the best Battery Chargers & Accessories at Advance Auto Parts this one is 70 dlls and has almost perfec reviews
will it work?

 

It would work, but you could only use the 2 AMP setting. Plus I can't determine if it set up for a AGM battery. A discharged battery rated at 45 amp hour would take a minimum of 24 hours to charge and even then might not be fully charged since charging of batteries always loosing energy in the charging/conversion process.

Ideally you should use a 4 AMP charging rate with a smart charger that has a selection for AGM. A decent smart charger will have those settings.

You really don't want to charge higher than 4 AMPS on the Prius unless the battery is disconnected from the car. Also since a AGM type battery utilizes a higher voltage algorithm, if you used a regular battery charger the AGM battery would NOT be fully charged when the charger turn off. Even disconnected Toyota states NOT to recharge their battery with anything over 4 AMPS. With all that said, the only thing you could use with the charger above is 2 AMPS and it will be slow...

Your charging times will vary depending on the SOC (State Of Charge) of your battery at the time of charge along with temperature and other factors.

 

how about this one?

AutoCraft Gold 3/5/12/30/100 Amp 6/12-Volt SpeedCharge Automatic Battery Charger/Tester XC-103: Order best Battery Chargers & Accessories at Advance Auto Parts


im trying to buy from advance since they have a ridiculous discount of 30dlls over 100 purchase, they do have another for 124dlls but is sort of too big, i dont know how to check if it can be used at 4 like u said, can u take a look please? also, the charger needs to be plugged in when charging the battery right? thanks for your help

 

This would be better:
Amazon.com: CTEK Multi US 3300 12-Volt Smart Battery Charger: Automotive

 

hi thanks,,, does this device has to be holocked up to your battery permanently? for example on my prius

oh, sorry, i just red you do have to plugged on to wall to recharge the battery, like i was tellin the other guys here i drive my 2009 prius every day 14 miles both ways so its about 35 minutes drive every day, how often do you recommend me to perform the recharge? once a week? every 2 weeks? thanks

 

I would recommend the CTEK Patrick Wong posted over the two chargers you linked Pepelily.

Of course they have to be plugged in to a 110 volt outlet. You don't have to permanently connect it to the Prius. Several use the jump post for battery charging.

 

Given your daily usage pattern, after you've fully charged the 12V battery, you should not need to charge it more than once a month or so.

If you think that the 12V battery does not hold a charge, then you should attempt to measure quiescent current draw when the Prius is IG-OFF, all doors and the hatch are closed, and the Smart fob is more than 20 feet away from the car. This will require the use of a digital multimeter connected in series with the negative battery cable and body ground. The current draw should be ~0.02A, or 20 milliamperes.

If the actual current draw is much more than that, then there is something wrong with your car.

If the current draw is as expected and the 12V battery does not hold a charge then you need a new 12V battery.

 

Listen to Patrick, he knows his stuff.

 

thanks for the info, ANY MULTIMEATER WILL WORK for battery check and draw as well?

 

Yes, you need a digital multimeter, which also can be used to measure battery voltage.

 

Most digital meters will have a amp reading on them. Best to look at the meter you are interested in to confirm that. I have two cheap meters and both of them have amperage both AC and DC. Beware of the limits of your meter. Excessive amperage can blow the meter. Example - measuring amperage on a 110 volt line with 15 or 20 amps flowing will burn up a little meter only rated at 10 amps max. Not only that it would probably melt the probes and the lead wires.

 

I would say, "can blow the fuse inside of the meter." Unless the meter is so cheap it is not fused, in which case I would avoid that model. After >40 years of sticking probes on circuits, I still screw up from time to time, and that little fuse needs to get changed.

 

thanks patrick... i guess my car is ok now with the new battery and the one i got 2 months ago just was a lemon, it has been 2 days than my car is reading 12.6 or 12.7 no matter morning or night, battery is fully charged, if i had soething draining my battery i would've known already, however i already order the charger and i think it wount hurt my battery if i charged it every 3 or 4 weeks, right? thanks a lot

 

If it will hold a charge overnight without dropping then I would say you are better off now than where you were. Compare voltage values after the car sets a couple of days if you can. No drop there is even better. Remember the SKS pulls a steady flow, less than 20 milliamps for sure but won't drain the battery real bad unless it is weak. You can always disable it with the button below the steering column if you choose to, but then the smartkey wont work. You would have to use the keyfob to get in... 12.6 volts is pretty good depending on how you measured it. And it won't hurt to charge it once a month. Just use a good smart charger like we talked about. Set it on AGM and don't charge over 4 amps.

Best of luck to you. I think you have a handle on it now!

Ron (dorunron)