Trickle charger and 12 volt battery

The real problem is that Optima makes an incredibly over-priced and unreliable battery... Lots of Opitma failures are going down all around, even with brand new ones. Friends don't let friends buy Optima.

 

My BatteryMinder is only a few days old but I'm seeing higher voltage readings already. You'd think driving 20000 miles a year would be enough but apparently it isn't. I'm now seeing 13v briefly during the time the Prius is shut down & the ScanGauge turns off. Everyone else raves about them so I figure in the worst case it is like chicken soup in that it won't hurt.

 

In the US Batteries Plus is local most everywhere and they carry lots of battery options...

Also BritPrius on Prius Chat has loads of info on the very best and least expensive batteries that work in the small space.

The confusion is that a Prius 12volt just runs electronics it doesn't run a starter to get the engine running so batteries that run electronics are ideal to use and less expensive to use, but because it's an automobile everybody freaks out and applies rules that aren't relevant to the demands placed on the battery. What's worse because the battery doesn't run a starter it can be a really bad battery for a long time before you start to notice you have a problem.

Meanwhile Optima who had a steller reputation for car batteries that ran car stereos in the 1980-1990's was well positioned to fill this niche market for the Prius in the 2000's. And while the Optima marketing department found success in that effort, the battery maker was purchased by a big corporation that moved the battery factory to a toxic waste site in Mexico where for the past decade they've produce super-cheap super low-quality unreliable batteries that not only look really cool, but they still have a stellar reputation because of the quality they provided in the 80's and 90's. And the profit margins on these Yellowtops are through the roof!

I actually read one post on here of a guy who went to a Prius repair shop for a bad Optima and they showed him a pile of 10 dead Optima batteries that failed.

 

The good news is that the demands this car's puts on 12volt batteries is incredibly minuscule....You could probably get away with a used motorcycle battery, though i wouldn't recommend it.

 

youngnbald, the really good news is that while PriusCamper's opinion on the price of our batteries is open for debate, the rest of his claims regarding issues with product quality and our production facility are absolutely false. Unfortunately, many of the “bad” batteries returned to us under warranty now are actually just deeply-discharged and work fine, when properly-recharged. In fact, I have a workbench full of "dead" Optimas that we refer to as “adOptimas,” because we find new homes for them after we recharge them, rather than just sending them off to the smelter.

This is not an issue unique to Optima. In fact, some other manufacturers have dealt with it, by simply voiding the warranty on their batteries, if they are found to be discharged below a minimum voltage level. We didn't do that with our warranty, but we did create this YouTube video, which explains how to recover deeply-discharged batteries.

Have you checked the voltage of your battery directly at the terminals with the engine off?

Jim McIlvaine
eCare Manager, OPTIMA Batteries, Inc.
OPTIMA® Batteries (optimabatteries) on Pinterest

 

I love it... not only do they sell bad batteries but they resell bad batteries and think saying so will help them promote the quality of their product... LOL... Not sure if you worked for Optima back in '80 and '90s Jim but ya'll were the bees knees when I worked in car stereo installation. Too bad things changed when you got bought out.

 

youngnbald, when you do charge the battery on your Envoy, measuring the voltage before charging will give you a good idea of how discharged the battery is when you start charging.

PriusCamper, once again, you are reading something someone posted on the internet and jumping to conclusions. We don't sell adOptima batteries, we give them away. My wife has been running a "dead" YellowTop in her truck for several years now and many of the racers in the Chumpcar World Series are now running adOptimas in their race cars. Even the folks who have been with Optima since the early days will tell you our state of the art production facility, which was built using Six Sigma methodology, is responsible for the best batteries we have ever made. and is ISO/TS-certified 16949 for quality management.

Jim McIlvaine
eCare Manager, OPTIMA Batteries, Inc.
OPTIMA® Batteries (optimabatteries) on Pinterest

 

This is an old post I'm replying to, but I'm confident that there are people like myself who are searching and finding this information and making decisions based off it.

I want to add some insight and some additional information that I frequently don't see mentioned in these old posts, especially by people with lots of posts.

Key points I want to point out,

A. Your 12V battery has a "power life" to it just like your cell phone.

The Yellow Optima I bought several months ago is rated at 38 AH (38 Amp Hours, or 38,000mAh)
The battery I removed (updated from Tech Service bulletin) is 54 AH (54 Amp Hours, or 54,000mAh)

* The bigger the number, the longer it will run between charge cycles.
* Although it lasts shorter, it's deep cycle technology is supposed to prevent permanent damage when drained extremely low.​

B. The Prius drains more battery juice than you think, when it's off (all doors closed, lights off).

- I measured ~140mA continuous draw when off. That's a lot.

~160mA total with a Bluetooth OBDII in the OBDII port. (yours may draw more/less)
~240mA total with Bluetooth OBDII & Progressive Insurance Snapshot plugged in.

** The Progressive Insurance Snapshot draws a lot of power, even when the car is off.​

* I haven't measured this on a traditional car/truck, but I imagine it's >80% less.
* I've read that a Gen 2 may be ~40mA, and newer generations ~16mA.​

* To put this into another perspective,

My Google Pixel phone, has ~3,000mAh battery and while the screen is on, drains at ~350mA/hr.

Doing the math, in ~7.7hrs, my battery will be at ~10%.
That's fairly accurate.​

* For the car with a 38 AH battery,

IF you start at 12V and IF car won't start below 10V, and IF you drain at ~140mA
Math says you will hit 10V in ~45hrs (~1 3/4 days idle).​

* 54 AH battery, 10V in ~64hrs (~2 1/2 days idle)​

* I've survived parking idle for >3 days before, so just take the above calculations as estimates. Outside temps, battery temps, battery health, and many other factors will effect this.​

C. The Prius charges the 12V Auxiliary battery "slowly". (Because it charges from the HV battery, how fast it charges will depend on the HV battery's SOC, or how charged it is too.)

- Fast in comparison to a 750mA trickle charger.
- Slow because it only charges when you drive it.

- When you drive it, it's also drains faster 140mA. I have no idea, but I predict ~ 1-3A.

- My pixel phone can charge at 3A. Car total is now 3-6A, not 140mA.
- GPS, radar detector, passenger's phone also running power? You get the idea...​

D. In 2001, they didn't build spec the Prius to handle charging modern phones, tablets, phone battery packs, Bluetooth OBD2, GPS, on a daily basis. You risk daily draining your battery faster than it can charge again if you power/charge all those devices.


CONCLUSION:
- Research AH (Amp/Hours) for batteries when buying them. That tells you how long it will last.

- The problem frequently isn't a bad quality battery, but you/we are using the car well beyond what it was designed for in 2001.

Because of our devices, we need x2, x3, x4 higher capacity batteries, or x2, x3, x4 larger AH (Amp / hour) 12V batteries and faster 12V charging.​

- If your car needed a jump start once, it will REALLY struggle to charge enough to be full again.

- If you didn't have an Optima battery, then your maximum capacity (Ah) may be damaged. Instead of it being 54 AH, it's now 50AH, then 46AH, then 44AH, etc...

 

With no accessories drawing power, on our 3rd gen I measured around 18 milliamperes, with sporadic spikes (say every 15 seconds or so) to around 40.

 

We purchased a 2003 Prius in September '17. It had a few issues of which I have apparently solved as we have not had any of the old issues return. One of the areas I paid close attention to was the 12V battery voltage. Initially I checked it output @ the battery (post) and used the MFD. Decided to begin testing it @ the fuse boxes (engine compartment) Reading began around 11.98 - 12.02V. I purchased a battery maintainer rated at 1.25 amp charge rate. It can be left on to bring the battery up and maintain full charge level. It took approximately 2 months of monitoring and selecting when and how long to attach the maintainer. Voltage now range between 12.78 - 12 89. Rarely dropping below that range. I have check the 12v @ least once a week but I feel that schedule may now be lengthened. I feel the 12v battery health is key to the vehicle overall operation. I purchased the maintainer from Amazon, but Walmart now sells the same unit. There are adapters/harnesses you can install that will allow you open the trunk and plug the maintainer in w/o gaining access to the battery. If anyone needs additional info, please post. Peace to all.