Starting battery: which one to buy?

But not just any old "lead acid" type.
Should be AGM for a couple of reasons.

 

My main concern with a lithium type battery is cold (and hot) weather. The battery sits in the car in the elements. Charging at temperatures below freezing usually kills off a big percent of their capacity each time you do it.

Of course there are low temp lithium type batteries, but I haven't been able to find much on their longevity.

I guess at the end of the day, like @PriusCamper said, with a good BMS you should be alright. The question (to me) is if that BMS needs to include thermal management or not.

 

Buying a good BMS is not easy... The ones sold online are generally marked up to a very high price and then you can go to a foreign site like Ali-express or alibaba and find something similar for less than $5 but shipping could take months.

If anyone knows of a good BMS source that's not overseas, I'd love to know?

 

A good alternate chemistry battery designed to drop in to replace a lead/acid should have the BMS built into it.

 

There are indeed charging issues with Lithium Batteries, they are prone to overheating if the charger is not set up for it. Not only can that prematurely degrade the battery, but can cause fires. A deeply discharged battery can get extremely hot when charged too quickly.

Like most things on the Prius, I tend to stick with Toyota OEM parts which have given good longevity. Moreover I noticed that typically once or twice a year one dealer or another in my general area has an installed Toyota battery service special.

 

Looks like there’s been a significant spike in battery prices, and a decrease in availability. One article I read speculated it’s covid related, so may cars sitting idle, lots of batteries dying, which sounds plausible.

 

That depends on the chemistry. A LiFePO4 4-cell battery has one of the closest voltage and charging characteristics to a lead acid battery than most any other lithium rechargable battery, so are most likely what you would get if you were to replace your 12V lead acid battery with a lithium solution. They are also non-flamable.

 

May be why Tesla changed to LiFePO4 in some models recently

 

Maybe that's part of it. I do believe there are many other benefits to LiFePO4 batteries (cost, availability, eco friendly, performance, perhaps longevity, etc) with the exception of one thing, capacity.

Other Li-Ion batteries pack more energy per space and weight. But on lower range cars using LiFePO4 makes sense. No cobalt or other exotic materials and you don't get news reports of how your cheaper cars burnt down a few houses.

 

@Mark in NY and @Hybrid Hound, perhaps others, have replaced their batteries with this LiFePO4 one designed for the Prius: 12V Lithium Battery for Toyota Prius | ohmmu.com

 

Looks interesting
5 yr full replacement warranty
$350 delivered without core?

 

Saskbattery sometimes have Prius S46B24R GS YUASA in stock. Need to just ask. Curious why USA and Canada Yuasa dealers only show motorcycle and wheelchair batteries. Didn't reply with my location at that time. A similar Yuasa battery GYZ32HL 32AH 500cca shows $219 shipped. Will check on Yuasa Prius price again.

 

I bought the yellow top Optimum battery when my car was 6 years old. It was around $250. Installed it myself. My prior battery experience taught me to change it before it tells you "I'm dead".

 

Well sure, if it gives you some warning, like hard starting (on a conventional car). I have had batteries on conventional cars die without any warning. It is pretty common for that to happen after a battery is exposed to extreme temperatures (either way).

With the Prius one must check the actual voltage on the starter battery to see that it is on its way out, when it will be below 12V. It is possible to do that using a magic MFD incantation in one start mode, or with a voltmeter, but it seems very unlikely that most owners do either of these tests routinely. I suppose one could load test it too, but since normally it doesn't see much of a load, I'm not sure how great a predictor that would be for "remaining life". I'm guessing that a Prius starter battery would work just fine with only a tiny fraction of its remaining capacity, so long as its voltage stays above 12V when it has to start the car.

 

The load test, in particular using today’s electronic load testers, is still a reliable predictor of a 12 volt battery’s viability, regardless of the Prius battery not turning over the engine. When cca falls below spec, and the tester gives a fail verdict, it’s time.

 

Just got a reply from SaskBattery for the YUASA S46B24R OEM Prius

 

Thanks, made a note of that.

My Optima Yellow Top, purchased through SaskBattery almost 6 years ago, is still apparently like new. We're driving less-and-less, but I keep it on life-support pretty much round-the-clock, with a CTEK 4.3. Electronic load test continues to pass it, with CCA well above spec. But someday, can't be that far off..

 

Any reason CTEK is a battery tender of choice? Looks expensive.

 

Yes Ctek jumped in price, I bought the 7002 7 years ago for $69, now its $168. I also have a number of the Battery Minder from Northern Tool when they were $25 also 7 years ago, couple months back they were still under $30.

https://www.northerntool.com/shop/tools/product_200332201_200332201

Maybe best to get the Noco 1 amp for $29 at Amazon online, not sure if links to Amazon allowed, not a fan of Noco, find they are also over priced, this seems like a decent price.

OK, Amazon link not showing. Here is an image capture. Better grab it while its discounted.

 

Both of those units are probably good BUT..........I would be leery of anything that mentions "trickle charger" OR that claims to be able to "deslufate".

You can't hardly go wrong with a Battery Tender brand unit.. A model in the 2 to 4 amp range is a bit more versatile.