Overcharging & AGMs

[Rob S.]

It was several months after I bought my 11E that I first accessed the battery. By removing the sidecovers, I could see it, but it was impossible to see the electrolyte levels without removing a frame submember and the dreaded air box. As I recall, two were about halfway and one was even lower.

I went to pods so I could check it more frequently, but it was always the same story. Three cells were very low, and the vent tube was usually missing (sometimes just disconnected). It only caused a problem on the road once, but after a short push it bump started.

I'm not a DIYer, but I like to sound as knowledgeable as possible and ask the right questions. Yes, I've installed batteries, but since it's going in for a handful of problems that are out of my league, I may as well leave the battery to my mechanic. I figure I'll go with an AGM, not the cheapest nor the most expensive.

Do the symptoms I had sound like overcharging? I always just chalked it up to an old, unmaintained, possibly damaged battery (I think it was always the same cells that were low).

What happens when a sealed, "maintenance free" battery overcharges? How is an overcharging problem fixed? New stator, R/R?

Overcharging just never occurred to me until someone brought it up here last week, I guess because the opposite problem seems to be so common to these bikes.

Thanks for six years of help.

 

[Steve]

Overcharging usually results in the electrolyte "boiling off". It usually happens in all of the cells, though. It's possible that you had a hairline crack in those cells or the vents in the other three were clogged.

AGM batteries are a bit more tolerant of overcharging. First reason is that they like to be about a quarter-volt higher to start with, second is that they are sealed, so the electrolyte simply can not "boil off".

Have you upgraded your R/R yet? Installing the SH775 will go a long way to minimizing the chance of overcharging, along with increasing the chance of maintaining the charge.

When you go shopping for an SH775, be aware that there are MANY fakes out there that look a lot like the real thing. There are several points where they differ, but you have to know what you are looking for. Fortunately, most of these points are easy to see in the typical pictures in the eBay listings.

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[Rob S.]

So if it's a genuine Polaris I'm safe?

What are the give-aways that it's fake, and the evidence that it's real?

 

[Steve]

So if it's a genuine Polaris I'm safe?

What are the give-aways that it's fake, and the evidence that it's real?

The video that jabcb posted gives the highlights. Many of the newer fakes are starting to incorporate some of the evidence, but none of them have ALL of the points.

To help in your eBay search, you can choose to looke for "Polaris regulator" or "SH775" or whatever, but also enable some search options. Limit your search to "US only" to weed out most of the Chinese stuff, and then select "used". That will weed out the new ones that "replace" an SH775. I also sort by price, from low to high.

I have not searched for a few weeks, but the last batch I found were in the $55 range.

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[Nessism]

In addition to installing a SH775 it's important to wire the unit correctly bypassing the stupid original Suzuki wiring. I posted a simplified schematic that shows what to do.

 

[Gorminrider]

It was several months after I bought my 11E that I first accessed the battery. By removing the sidecovers, I could see it, but it was impossible to see the electrolyte levels without removing a frame submember and the dreaded air box. As I recall, two were about halfway and one was even lower.

Do the symptoms I had sound like overcharging? I always just chalked it up to an old, unmaintained, possibly damaged battery (I think it was always the same cells that were low)

Both of these. batteries can lose water even when not overcharged...You yourself should have checked electrolyte levels immediately when you bought the bike. Flashlights and wiggling can help where the battery made of that stupid white plastic they use.
as to which, you don't know without tests.

What happens when a sealed, "maintenance free" battery overcharges?

Severely overcharged, they are ruined where an old wet-cell might survive if the lost water is replaced in time.
https://batteryuniversity.com/learn/article/absorbent_glass_mat_agm


AGMs were made for people who don't like to do maintenance and for machines that can fall over. Some advantages for sure. But they require more care in the maintenance of connections and components.
Putting new stuff in is a way to force people to make new connections that will last awhile. Usually until they put the bike away poorly and otherise neglect it until the same symptoms reappear and they repeat the process again or pass them on to a new owner.