Another battery for the Prius.

I installed the new Exide battery today, and the voltage was 12.9V after more than two days of rest. The old GS Yuasa battery will be four years old in July. It measured 12.5V so it did not need to be changed at this moment. I'll take it home and charge it up and see how it does.

The only problem with this Exide Edge AGM battery is that the vent hole is too small to fit the black hard plastic vent fitting. If I had my electric drill available, I would try enlarging the vent hole. I'll contact the battery store when I get home to see if the correct fitting is available for the Exide battery vent hole.

Attached are a few more photos to document what the vent hole looks like, the voltage of the old battery as of this morning, and the new battery's no-load voltage after charging and being at rest for 2+ days.

 

There are now a few different "direct fit" aftermarket 12V batteries for Gen2/3 Prius.
Who knows, maybe they're all made by the same company with different labels.

The original 12V batteries are dying, so the aftermarket has started making them...too bad they still cost at least twice as much as a "regular" 12V battery cost.

We change out 1-2 per week at our shop in Boulder.

BTW, measuring 12V battery voltage while car at rest with a simple voltmeter doesn't tell you too much about battery state of health.

Test the battery with a load tester and/or internal resistance meter on a cold morning before you turn on the car. This procedure is way more useful.

 

Saw this video and wondering if anyone has tried that on Prius.

 

Which battery do you sell?

I agree that measuring battery voltage will provide an indication of SOC but says nothing about Ah capacity. Need to use a load (like headlights) and measure drop in battery voltage to get a subjective indication about the latter.

 

We used to sell Optima Yellow Tops, but had quite a few fail within 2 years.

Toyota changed their offering in the last few months so now we use Toyota SureStart, they cost around the same as Yellow Tops but have 24 month full exchange warranty and 84 month pro-rated warranty at any Toyota dealer. This is a good option for the customer IMHO, but we're always on the lookout for other good options.

We charge $225 installed. The dealers around here charge closer to $300.

 

Looks promising as long as the car does not sit for more than a few days.

 

I got home yesterday and charged the GS Yuasa battery at 14.2V. The current stabilized at 0.1A after 22 hours of charging time. Then I lowered the charging voltage to 13.8V and the charging current stabilized at 0.09A.

The battery seems to be fine so I'll install it in the 2004 and keep it in service for a while. The battery currently installed in the 2004 is around three years old, so I'll charge it fully, then keep it as a spare, periodically recharging it while in storage.

 

Patrick,

What did you end up doing as far as the vent hole?

Also, how is the Exide faring?

Thanks.

 

Nothing - the car is 500 miles away and I haven't yet gotten a suitable fitting to insert into the vent hole. So the battery is free to vent into the space that it sits in, but I consider this to be a minor concern.

The Exide battery is fine after 10 months of usage by my daughter. I bought her a portable jump start pack, jump cables, and a battery charger (to help her deal with future battery problems), and explained to her how to use all. Of course, now that she has all of these items, she hasn't needed to use any of them - which is very good. Better to have them and not need them, than to not have them and be stuck somewhere...

 

Cool battery!

 

According to the below, the Exide was supposed to come with an elbow. Perhaps if you call Exide, they will send you the missing elbow?

12 volt battery for 2009 Toyota Prius | PriusChat

 

The one you got was supposed to have one taped to it on the side per the below. I wish they found a way to embed the elbow into the top cover (just like how the handle embeds into the top cover) so it's not lost easily for those that need it ...

12 volt battery for 2009 Toyota Prius | PriusChat

 

Thanks, I sent a msg to Exide to see if they can help, since the retailer that I bought the battery from no longer carries Exide.

 

The Exide battery that I bought in May 2013 (post #5 above) is now dead. The symptom that I noticed while driving the 2007 is that the overhead cabin lighting brightened substantially when the car was made READY. It was obvious that the voltage produced by the battery was way under 13.8V.

I tried charging the battery and found that the charging current would not diminish over time, and that the voltage produced by the battery was only ~11V. Hence it was clear that a cell was shorted. I returned it to the retailer, they confirmed the battery would not hold a charge, and I got a new Exide battery manufactured in July 2014. I even got the correct vent elbow which fits that battery! The store had partially charged the battery and I am now finishing that job.

In the meantime I reinstalled a 2009 vintage GS Yuasa battery that I had taken out of the car when I put the Exide in. I've kept the GS Yuasa in the garage, charged it every 2-3 months, and it has aged very gracefully. At a charging voltage of 14.4V, the current flow declines as the battery charge increases, and the final current flow is only ~0.04A which is like a new battery. Typically as a battery ages and loses capacity, the final current flow will be much greater, 0.2A or more.

 

Reading from your comment when you first purchased the battery, it arrived at only 12.3x volts. I wonder if that could be the reason for the short lifespan

 

Could be. The resting current at 14.2V was greater than I expected for a new battery (see my post #19 above.)

Also, the car's rear bumper was hit a few months ago so the car spent some time in a body shop. If the hatch and/or doors were left open for a prolonged period w/o first disconnecting the 12V battery, that would not help battery life.

I didn't bother to measure the voltage of the new battery tonight, since the salesman told me the battery had been on a charger immediately before I picked it up.

October 5 edit: After 36 hours of charging time the current flow diminished to 0.04A (at 14.4V charging voltage) which is what I would expect for a new battery.

I've attached a couple of photos which show the new battery's stickers and the correct vent elbow.

 

Patrick,

One thing I wish was better with the Exide battery I tried is that the plug for the vent hole on the other side doesn't seem snug or make a good fit. One might have to use some glue to make sure it doesn't fall off, especially when there's any kind of pressure in the vent system.

I am curious to learn if the new battery you got suffers from the same issue.

 

No, both the plug and the vent elbow both seem to fit well. I suppose you could use a super-glue to hold the vent plug in place.

The open-circuit battery voltage is now 13.1V, 1-1/2 days after I stopped charging the battery.

 

Is the tester that Toyota uses valid. I took a battery that I bought at a wrecking yard in Vegas that had been sitting and was low on charge. I paid $20 for it and I bought it because it was just a year and a half old. I charged it and took it to the Toyota dealer and had them test it. They give you a print out of the results and that battery was good to go. It measured 453 CCA and the state of health was high. I installed it in my 08 Prius which had the original battery. I tool the original battery to Toyota and the test was to replace the battery. I had noticed on my dash ScanGauge that the voltage seemed a little low starting out in the morning.