Upgrading the battery

Correct. I'm trying to avoid having to buy a hugely expensive battery plus a charger. It isn't the money really, but I know I'll forget to do it from time to time and would rather have to not think about it.

 

Ask yourself and be realistic about what you need to do with your battery. I started out thinking I needed a dual battery set up after reading some posts here and after thinking about it logically I ended up with a single 34R AGM from NAPA (made by Deka).

My criteria:

• AGM battery made in the US
• Higher CCA and RC than stock
• Lighter or same weight as stock
• Around $200
• Support in case I need to use the warranty (NAPAs are everywhere)

The 34R from NAPA met all of the criteria and is actually a bit smaller than the 24F. The only downside to this battery is it only came with a 24 month warranty. However, it was only a bit over half the price of a battery with twice the warranty (that still meets all of my other criteria). I'm willing to live with that, given the good reputation Deka has.

Your criteria will differ but laying it all out and thinking with your head rather than your heart will help make the decision much easier.

 

As near as I can tell, the tray form a 2 gen which will fit a 27F is part number

$58 744310C020 TOYOTA Genuine (74431-0C020) Battery Tray

744310C020. Around $35. There are aftermarket ones available but they my need some modification. In a pinch, you could just dremmel off the end lips on the stock tray. This would allow the 27F to fit flat with a little over hang. Since the AGM is not going to leak, the lip is probably not needed provided you can tighten the clamp enough so it doesn't move around.

I've gone back and fort on a 24F vs a 27F, and I think I'm going to go with the 24F AGM. I don't run refrigerators, winches or other such power drainers that might be on without the engine running so it might be overkill for me. Of course if you need that extra reserve, the cost, weight and fitment might be worth it to you.

 

sweet thanks!

 

I just got off the phone with someone at Odyssey. He said that their batteries require 14.7 volts from the alternator. I went out and checked my truck and the alternator is putting out ~13.97v at idle. I wasn't able to see what it outputs when I rev the engine because I'm home alone at the moment, but those numbers are pretty consistent with what @crashnburn80 reports in this thread on his second gen.

Now with that said, the tech did say that ultimately it probably wouldn't be a major impact day to day, but if heavy winching was done or the battery was drained significantly, the alternator would not be enough to fully recharge the battery.

In sum, the Odyssey battery has the same recharge requirements as the Northstar units. Meaning, that in order to take full advantage of what you pay for, with the 3rd gen. trucks, you will need to charge the battery occasionally from a 120v wall charger. Not the end of the world, but also not a true plug and play replacement.

This page on the Optima website leads me to believe the same is a requirement for their batters as well when it states: "Recommended charging information: Cyclic Applications: 14.7 volts, no current limit as long as battery temperature remains below 125°F (51.7°C)..." I did speak to someone at Optima as well, who could only read me this part of the same page: "Recommended charging information: Alternator: 13.65 to 15.0 volts, no amperage limit..." However, the person I spoke to kept having to refer these questions to her supervisors, and would only read to me what it says on that page. I did not get the felling that she fully understood what I was talking about. For comparison, the tech at Odyssey was clearly knowledgable about my questions, so take that for what it's worth regarding the current reputation of Optima.

I suppose now the question becomes is it worth the hassle to occasionally charge an AGM battery with the 120v wall charger. Overall considering the benefits of AGMs I think that yes, it is worth the inconvenience of having to charge it once in a while, but I am still going to mull it over for a few more days before coming to a decision. In the mean time I would like to get a reading of what my alternator puts out when the engine is revved.

 

I wonder if the number changes under load over a free rev. Also I think how often it would need to be topped off with 120v plays a huge factor for me!

 

I'm going to try and get the reading while being revved tonight when my wife comes home, but I know it won't come close to the required 14.7v.

 

agreed. I think depending on how often I will need to charge it. I think I’ll be going to the odyssey route.

 

That definitely is a deterrent for us 3 gen guys. I guess if you overland a lot and need the extra deep cycle of the AGM then you pay the price (charger plugged in) I don't do a lot of that sort of thing but I just might deal with a monthly plug in to keep things cool. Seems like 5-10 minutes a month is no big deal. I'm glad to be in a position that I don't worry about the costs of such things. Worst case, I spend $275 on an AGM and it poops out after 2 years. In the scheme of things I say Meh, I can't take it with me.

 

The is no way the alternator I had was pushing 14.7V and I charged that Odyssey battery twice in 11 years only because I ran it completely dead running the power window motor up and down a ton of times without the engine running. I would not overthink it, it was nice having zero corrosion on the battery cables all that time.

 

Did you have a winch? I think you're right that for the typical daily driver the AGM will be fine. But I think the concern comes into play with added drains such as a winch.

 

Note the alternator voltage output graphs in my AGM battery thread you linked, the alternator voltage fluctuates significantly over time, so taking a single reading is very hard to judge by. You will get highest peak voltage in daily driver use after the truck has sat over night and you do a cold start the next day. This is because the battery has been sitting for an extended period of time and taken a drain from the starter which then causes the alternator to work harder to refill the battery back to capacity. Once the battery is essentially recharged to capacity you will see the voltage drop off, even if reving the engine.

Not charging the AGM battery to the correct specified voltage (higher than the Tacoma stock alternator voltage) leads to sulfation of the battery plates which will degrade performance and reduce battery life. It isn't like the battery won't work, it just won't work nearly as well over time or last as long.

 

Thank you for clarifying that! What would be the ideal time interval to put an AGM on a charger? Once a month or more frequently than that?

 

Thoughts???

https://sdhqoffroad.com/collections...tacoma-3-5l-270-amp-xp-high-output-alternator

 

Once a month seems to be what is frequently suggested, I have an open question out to NorthStar for their official recommendation as well as recommended chargers.

Note this will not fix or address the voltage issue. This will address if your truck uses power faster than the stock alternator can provide it by exceptionally high current draw, such as heavy winching. The battery is basically an electrical storage tank, you can draw down the tank faster than the alternator can refill it, and that is ok to a mild point as the alternator can refill it over time. But if you have extreme draw with extended winching or other heavy electrical loads that exceed your alternators capacity, you could kill the battery as the stock alternator will not be able to refill it quickly enough. This is where a high amperage output alternator comes into play, to put out far more amps for heavy loads. However these alternators still charge at the stock voltage.

 

Thanks for clarifying!

 

Just upgraded the battery in my 2020 to a 27f x2 and it dropped right in like it was supposed to go there.

 

Brand?

 

X2 from batteries plus. Rebranded Northstar from what I have read on here.

 

My apologies. Over looked! Thanks for the info!