Fully charged 12v battery, yet no instrument lights.

the battery is probably bad, 100% of zero is still 100%. how old is it? driving a couple blocks a day is just beating it with a sledgehammer.
i would start with a load test. call around to auto parts stores, they are usually free.

i don't trust battery charger measurements, put a volt meter on the jump point under the hood and turn the headlights on.

 

You should use a digital multimeter and check for voltage at the underhood fuse box on the driver's side. This fuse box also has a little metal lug under a red plastic cover - this is where you are supposed to hook up your positive lead for boosting or charging. I grab a strut mounting stud on the shock tower behind it for a negative connection.

Anyway, grab a voltage reading there and report back. Yes there is the main fusible link assembly in that fuse box and if it's bad then it requires a bit of disassembly to change it.

Posted via the PriusChat mobile app.

 

You did that backwards. Use the underhood front jump point first that’s why it’s there. If the car is locked use the key in the fob. Make sure the door key hole is well lubricated many a Prius owner found after a dead battery that door lock was never used and now is rusted stuck.

but now that the battery is dead and needed a jump it’s probably toast and needs to be replaced. If you had a voltmeter we could prove it.

many reports of phantom 12 volt drain most just an old battery or a good battery that was killed perfectly by leaving a light on and now won’t hold a charge.
Some are a bad 12 volt battery brake back up supply the box right next to the 12 volt battery.

I do know for certain a G2 Prius is the last car in the planet you want to jump start the story’s we regularly see here of jumps gone wrong are ridiculous

 

Assuming a healthy 12v battery, try turning off the SKS feature (if you have it), which may prolong the life or 12v state of charge.

Going forward, you may have to drive/ready the vehicle for more than 20 mins per week to maintain a healthy 12v battery.

How many years has it been since this 12v battery was last replaced?

 

Ok..but .why are you looking at the fusible link?

Do you own a fluke quality voltmeter? If not buy one asap you are going to need one.if you had one we could test that 12 battery real fast but really your best play is just replace it. You do not want to mess around with 12 volt issues on a g2 going to be long winter,

And there’s very few places on a g2 to meet high voltage as an owner or dong casual maintenance. All high voltage leads are Large and orange
Just like the douche who’s leaving the White House.

But I’m afraid the truth is sooner or later the high voltage battery and your wallet are going to have a very close relationship.

 

This is to be expected. You don't drive far enough to recharge what the battery loses while sitting.

That's doing it the hard way. As Mr Guy Man said, there is a place for that under the hood in the fuse box. Page 362 in the 2007 owner's manual. Yours might be similar.

Naturally.

Booster? Is this a jump pack or a charger?

You might also have a loose or corroded connection.

THIS!!

I wouldn't be surprised, after pulling the battery that low and keeping it that low if you find that it's well and truly shot by now.

As for any high voltage, if the car is off, the only way to get in touch with high voltage is to remove some panels from the cargo area and take the case off the traction battery. If it's on, don't mess with the big orange cables.

 

start with the walmart booster. charge it up and put your voltmeter on it. '20' should be correct.

if it read close to 13 volts, discoonect the 12v battery and try starting the car with the booster.

very unlikely that the 12v is original. in 15 years, you could be on the 3rd or 4th.

there is a date code on the top

 

Better yet put your voltmeter across the charger and see what it reads.
Get familiar with your vm you seem to have no confidence at all which is not good when messing around with the Prius 12 volt system.

a selectable cheapo multimeter is a very poor choice for a rookie spend a little more get a fluke that has no settings it’s either AC or dc.

Because if you own a g2 your gonna need it.

 

Hi Tynyyn!

My Gen 2 had exactly the same problem as yours, and I fitted a a replacement battery, (Cost about 60GBP), which solved the problem instantly. Hope the same goes for yours

 

Thank you very much for the kind words Ty. I will assist you as much as I can.

you cannot go wrong with a new 12 volt battery on a g2. the best battery is the stock battery it’s a little more expensive but superior quality IMHO,
Mine lasted 7 years even in this heat.

I am on my second Optima yellow top there ok easy to get and have a solid 3 year warranty. Like $200 out the door minus the $30 coupon at the time,

My first optima which was very popular then after my oem battery failed lasted exactly 2 years 11 months and 22 days. Autozone gave me a new battery, I’m still on that one and watch it closely by routine maintenance charges which tell you a lot of info. The most important being when that battery cannot reach a full 13.8 charge after many hours on the charger start watching it closely.

having said that I have not bought a new 12 volt battery in 6 years there may be better choices so I encourage responses.

as far as fluke voltmeters please go on eBay and search Fluke Dvm. There will be thousands of choices,
Spend $100 on a new one it will last for years and years.it only has one setting for a and dc.

 

might be a bad mfd, are you getting the 'ready' light? power button green?

have you got a volt meter yet?

 

If it's an original battery there's a date code on it.

http://www.reddit.com/r/prius/comments/6ojjie/how_do_i_tell_the_age_of_my_12v_battery/

 

The first time you install a new 12 volt battery and go to start the car it willlight up all lights and freak you out. All 12 volt circuits went offline when the battery was pulled and the car freaks because of it.

Just let it sit for a bit and try to start it again it should start right up.

if not measure the the 12 volts at the front jump point. Should be at least
12.4 to 12.6.

then measure directly across the battery itself. There should not be more than a .5. Or half a volt difference. There’s 8 connections and a long heavy duty cable from the battery to the front jump post so there’s about a half volt drop
There.

do not be surprised it the battery is low many a poster has bought a new battery only to find it was sitting on the shelf a long time and was never tested or charged before you bought it and went low sitting there.
Especially if you see the guy take it right off the rack.

next time you go to buy a battery and the counter guy says here you go it’s all charged up say great that’s nice then whip out your NEW FLUKE lol
And test it on the counter.

 

I checked on Amazon get a fluke 15B voltmeter brand new nice meter you will own that one your entire life. On a g2 it will pay for itself first time you use it.

$125.