elearnaid/Optima replacement

If 12V posts bore you, please skip on.

My 2006 Prius Battery elearnaid/Optima experiences so far:

OEM battery used from purchase in early 2006 through early 2011. In 2011 for some time the key fob was not recognized remotely (had to insert the fob into the "key slot" to operate the car). I think there were one or two other oddities. I concluded this was a symptom of a weakening 12V battery, and indeed replacing the battery fixed the problems.

The elearnaid kit specifically for modifying a Japanese-post Gen 2 Prius to use a US-Post Optima battery was installed in January 2011.

In early 2014 the door was left open for many hours, discharging the 12V battery to 4V. I kept it in service.

Starting in early 2015 I made a monthly practice of topping up the 12V battery using a Battery Tender Plus. Typically it would spend 1 to 3 hours in the initial phase (1.3A charge, limited to 14V), and then would continue in the second phase until timing out at about nine additional hours. This second phase maintains a constant voltage at the charger end of the cable of about 14.3V, decreasing the charging current as required to honor that limit. Because of cable resistance, the actual voltage applied to the battery rises, from about 14V to about 14.3 or so.

In June 2019, my monthly charging session did not move on from first to second phase after about eight elapsed hours. A meter check at Prius fuse box point showed only 12.06V with the charger still running at 1.3A. I disconnected the battery tender and over the next few hours the voltage at that test point dropped slowly to 11.76. As it had charged properly a few weeks earlier, I judged that one cell in the Optima had failed recently.

As the U.S.-spec connectors were now in the car, my most obvious options were to buy another U.S. spec Optima battery and use the hardware in my car, or to take the car to the Toyota dealer--confess my deviation, and imagine they could put standard attachment hardware back in place, and install the standard Toyota battery for some tongue-lashing and an additional price.

As the Optima had given me about 8.5 years service, despite the insult of one deep-discharge incident without any car misbehavior at all, while the OEM battery had less than five years of service (without a discharge insult) before observable car trouble, I made the snap decision to buy another Optima from elearnaid.

Elearnaid still has a web page for the kit I bought, but clearly suggests no one should buy it. Now that Optima has a skinny-post model compatible with original Gen2 hardware they suggest that one unless you have previously done the US post conversion, or if you have previously converted they suggest buying just the battery. For $220 including good shipping I purchased the US Post Optima of the exact same dimensions I'd bought previously.

On arrival, the battery measured 12.77V. I put it on the Battery Tender Plus and it spent 3 hours in the first phase (so only adding about 4 AHr). The date sticker implied it was manufactured two months ago. I think the battery arrived in a healthy state. No country of manufacture or assembly was indicated.

While I still had the original elearnaid installation instructions, I was comforted by checking a few Youtube videos on the general topic of Gen2 Prius battery changes.

The one I personally liked best of the three I checked was:

I'm not very car-handy at all, and had a fair number of little troubles, such as finding it hard to get the white plastic connectors to release, and dropping a socket extender into the battery well, but all came right in the end.

Questions that may be of interest to other people who made the elearnaid fat-post conversion and installed an Optima years ago:

1. Is monthly topping up with a Battery Tender Plus life-extending? (in my case it appears to have served as a useful early warning of a failing battery).
2. Is there a better US post alternative that fits, compared to the Optima?
3. How much would a Toyota dealer charge to back-convert to original post clamps?
4. Is keeping the US post clamps going to harm re-sale value?
5. How many years did you get out of your Optima Yellow-Top?

 

If I had any brains I put them on the shelf with other auto stuff. But the clamp conversion was one of the less fun parts of the original install, and I decided I'd rather stick with the clamp and cable currently on the car, or have a dealer put it back properly.

So I've not searched for the old parts.

 

I got instructions with mine. There is a small chance I can still find them--I'll look.

I do remember that my instructions stated that one step might require an inconvenient high force, and that in the event I was barely able to do it. But I don't remember what tools and method I used. Sorry.

 

I've looked for but failed to find my instructions. I think perhaps I used my vise to get a firm grip on the one piece while using a good wrench to undo the stubborn fastener.