TR2/3/3A AGM Battery for TR3

[mgedit]

Considering an AGM battery for my 56TR3 with generator. I realize this may not be the least expensive option but I like the idea of less chance of leakage. Has anyone done this? Wondering if the generator can supply sufficient current with stock regulator setup to maintain proper charge to one of these batteries. Appreciate thoughts and especially real life experiences. Cheers, Mike

 

[3798j]

Have had AGM's (Optima Red Tops) in both the TR4A and the GT6 for many years. No problems or issues whatsoever. Both cars still have their original charging systems.

 

[mgedit]

Thanks Jay, are both cars using generators and if so what is there max output? Cheers, Mike

 

[3798j]

Both still use their original installed generators (pretty sure the GT6's has never even been re-brushed).
Now, while Optima Red Tops are AGM's, they're still lead acid batteries. I'm starting to think you might be actually asking about AGM lithium batteries. Think possibly they're charging needs might be different.

 

[Tr3aguy]

https://www.tartopper.com/

Maybe this will help?

 

[3798j]

Below is some possibly helpful information. It's from another forum I visit. It's taken from a discussion on AGM's:

"After much research into the AGM advantages and the primary battery manufacturers, like DEKA, Johnson Controls, Exide, etc. here are some salient points":
1. AGMs have a (lower impedance) higher power delivery rate which makes them ideal for the new start stop engines.
2. Since they are sealed they effectively recycle the hydrogen gases and recombine with oxygen to replenish the electrolyte (they don't lose water as vapor). Only when overcharged do they release gases via a high pressure valve for safety, but this does result in the battery's ultimate demise because the electrolyte balance is unrecoverably "off"
3. AGMs have a lower static discharge rate, so they are preferred for garage queens. They can be sustained, conveniently, with the same battery tenders as Flooded Lead Acid batteries, but check with the manufacturer. I know that the Griot's maintainer, Battery Tender and BMW branded tenders work A-OK, as they never exceed 14.7 volts peak charge. AGMs don't like 14.8 volts or above
4. AGMs don't mind vibration and are leak proof. A nice consideration for our trunk mounted Bimmer batteries... Motorcycle guys love them.
5. More CCA in equivalent sizes compared to LA, but not by a huge margin.
6. Since DEKA makes the AGM Super Start O'Reilly and NAPA AGM Exact Fits, they are a bargain against the OEM (BMW) AGMs. All appear to be made by DEKA....

 

[DNK]

Think mine is an AGM in my Wedge

View attachment 27008

 

[mgedit]

Thanks all. My concern is that the 19 or so amp output from my TR3 generator might not be enough to maintain the battery. I thought I had read something about that concern with regard to AGM batteries somewhere, but of course cannot find that discussion now. Cheers, Mike

 

[Lou Metelko]

Installed an Optima red top in my TR2 (TS981) when car was finished in 2003. Original generator, original starter, points ignition. Battery Tender maintains through the winter hibernation. I chose the Optima due to my paranoia with acid leakage. When battery did not have enough oomph to start car in spring of 2012, it was replaced with another Optima. The 2 is driven, on average, about 3000 miles per season. I highly recommend the Optima - you will not be disappointed.

Lou Metelko
Auburn, Indiana

 

[mgedit]

Thanks Lou ... exactly the kind of feedback I was hoping to find. Cheers, Mike

 

[Geo Hahn]

OTOH -- I never had a traditional lead-acid battery leak. They will vent some nasty gases if they are overcharged but sounds like the AGM do that to.

The advantages of the old style battery seem to be that they are cheap, are easily charged if need be and look more period correct (though I realize there are some AGMs made to look period).

The disadvantages are perhaps that the electrolyte level should be checked and maintained and they must be kept upright & secure.

I think plenty of CCAs are available in both styles.

 

[martx-5]

I install AGMs in all cars that I decide to keep more then a few years. The original AGM Battery in my Miata lasted 14 years. The one in my TR3 doesn't have a tender on it, as I just charge it up every other month with a small battery charger and it performs fine.

Here are the charging recommendations for an Optima Red Top...pretty liberal.
[h=2]OPTIMA[SUP]®[/SUP] REDTOP[SUP]®[/SUP] Charging Information[/h] The following charging methods are recommended to ensure a long battery life. Always use a voltage-regulated charger, with voltage limits set as described below.
REDTOP[SUP]®[/SUP] Type: 34 & 34R - 34/78 - 78 - 25 & 35 - 75/25
These batteries are designed for engine starting applications. They are NOT recommended or warranted for use in deep-cycle applications.
[h=3]Recommended charging information:[/h] Alternator:

• 13.3 to 15.0 volts, no amperage limit.

Battery Charger:

• 13.8 to 15.0 volts, 10 amps maximum, approximately for 6-12 hours.

Rapid Recharge:

• Maximum voltage 15.6 volts (regulated), no current limit as long as battery temperature remains below 125°F (51.7°C). Charge until current drops below 1 amp.

Float Charge:

• 13.2 to 13.8 volts, 1 amp maximum current, time indefinite (at lower voltage).

They are expensive, but are rugged and will outlast a lead acid battery three to four times over.

 

[mgedit]

Thanks for the additional information. Cheers, Mike