There was discussion about the best agm battery to use in a 914-4. Someone mentioned the Optima Red Top 34R being a good choice, but their website says that this battery will not fit. Can anyone advise what AGM battery they have used in their 914 with no fit problem? Thank you for your help!

I just put in an odyssey with Patrick motor sports hold down. Looks really nice and fits perfectly.Click to view attachment

I use the 34r with no problems, fits easily...

Odyssey PC680 is my favorite. Small, light, works. Next time I buy though, I will be looking at lithium ion. It's getting there for cars, and they are crazy light weight for their power.

I have a PC 680 in my car not much bigger than a motorcycle battery, only complant is it won't turn over a new engine for break in.
To me a better choice for a DD or every weekend car would be the PC925, still almost half the size and weight of a regular battery.
A full size AGM is overkill.

Would someone please post a pic of this AGM battery.

the picture is hard to see.

https://www.odysseybattery.com/Batteries/Model_PC925

You can use the PMS or Rennline battery mount kit.

Optima are junk, they started using recycled lead about 10 years ago and the warranty rate went through roof. I worked at one of the top 3 Optima retailers in the US.

Optima 3478 battery fits just fine; battery cutoff switch added to reduce fire risk and add thief deterrent

Click to view attachment

This Optima battery is about ten years old & works just fine. FYI.

34r Red Top (yep, just painted it to match the car...)
Tons of room....

Click to view attachment

Has anyone tried a Group 47 battery in a 914? Same footprint as Group 42 but 15mm taller. I'm guessing it hits the rain tray but curious because Bosch makes an AGM battery in that size.

You want it for period correct Look?

They make covers for the Optimas Odedessy Even Delco and Deka that make it look like the old lead acids, if you are going period look.

Click to view attachment

Tar Topper Make Modren Starting Power look period correct

Not necessarily. More just curious about other size options. I do like that Bosch have bottom hold downs molded in though. I'm not crazy about the look or price of the battery hold down kits. Not an issue with Optima I don't think and I have one in my work rig/snow plow that has been bombproof through more than 10 Montana winters, but I've read several places that their quality has gone to

Funny little Chinese Vision AGM still going strong after a long time (4yrs),cheap and only 9lbs,hell @ less than $80 to buy and with that weight you could carry a spare.
Sold as a racecar battery in my country but plenty of cranking power for my six.
I have since built a custom battery tray for it which is future proofed to the next larger size if needs be.
Click to view attachment

I've had good luck with Optima's. I keep it on a battery tender jr. The guys at the shop "borrowed" one of my Optima's to start a car. It was low so they put it on a fast charger set to 11. Blew out a cell in the battery. I think following the directions for the Optima's is really important. I am going to experiment with some ATV lithium batteries since they are super light and seem to work ok. Quick way to loose 30 lbs.

That was a few years ago. They say at my local distributor it was a bad factory in Mexico and that they have fixed it up now. Just have to cut off a tab that is not needed making the battery case on the base too long by 3/8 or so

They were very good 15 years ago. I put one in my 76 car a few years ago and all good.

Bob B

I want to add an isolator like that ,is that the standard Hella cutoff switch ?

I just bought a cutoff switch from Amazon

https://www.amazon.com/gp/product/B007O0BBF...=UTF8&psc=1

I made the box from a plastic outlet box and cover.

I'm currently running the Bosch 96R size battery and it fits perfect. I've had it for three years with no issues. It's connected to a battery tender in the off season.

Yep; just put an Optimum Red 34R. THey new come with all sorts of adaptors; fit perfectly (though I preferred to shave a bit off each bottom side to slide in/out of the battery tray a bit more easily. The hold-down clamp (4-5 options included in each one) is great. Just make sure you get a fresh one - lots of old ones still on shelves....

A word of caution for those with the factory rain tray looking to buy an Optima. Buy the 34 (NOT R). It puts the posts on the outboard side of the battery so the decklid will close without interference.

The biggest benefit with a AGM is the low discharge rate ,ideal for a weekend car or garage queen that has little use ,battery tech has come a long way so we don't need to carry around 30+ pounds of extra weight with a wet cell.
Downsides...mine has a really small 6mm bolt post setup,I have adapted to that but a pain,they DO not like being run really flat and for that reason they will not last as long.
My main point is you don't need to spend a bunch on a suitable battery .