Create a New Forum Admin Login Member Login Contribute to Voyager Search VoyForums Help Desk VoyForums Exchange VoyForums Directory/Categories VoyForums Homepage VoyForums News FAQ - Frequently Asked Questions

[ Show ]

Support VoyForums

[ Shrink ]

VoyForums Announcement: Programming and providing support for this service has been a labor of love since 1997. We are one of the few services online who values our users' privacy, and have never sold your information. We have even fought hard to defend your privacy in legal cases; however, we've done it with almost no financial support -- paying out of pocket to continue providing the service. Due to the issues imposed on us by advertisers, we also stopped hosting most ads on the forums many years ago. We hope you appreciate our efforts.

Show your support by donating any amount. (Note: We are still technically a for-profit company, so your contribution is not tax-deductible.) PayPal Acct: Feedback:

Donate to VoyForums (PayPal):

[ Login ] [ Contact Forum Admin ] [ Main index ] [ Post a new message ] [ Search | Check update time | Archives: 1 ]

Subject: "Spirals... AGM's..wheelchairs Author: JD [ Next Thread | Previous Thread | Next Message | Previous Message ] Date Posted: 9:26pm The spriral cells look cool but I've read some things about them that suggest they can be problematic due to heat and overcharging. They also are way more expensive then standard glass mat batteries. Spiral cell and AGM use the same technology but in AGM the glass is between thicker standard flat plates rather then wound between thin flexible metal strips. Due to higher plate clearence, and thicker plates, they are less problematic. Sprials have more cranking amps because there is a higher surface plate area, but they don't last as well or take abuse like the standard AGMs because the wound plates are thinner. Essentually the were designed for automotive use. Kind of a high crank AGM for cars. They are more durable automotive style lead acid batteries in boats (no sloshing) but still not as sturdy as the standard AGM because of the thin plates. For those who don't know.... AGM batteries are like standard lead acid batteries except they have a glass filler material between the plates. The biggest problem in batteries is surface contamination of the plates. Repeated charging creates contaminents. Sloshing electrolite washes them around and gets them on the plates. This is worse in boats because the batteries are constantly rocking around do to boat motion. They are both stirred and shaken The filler in AGM's prevents sloshing and plate contamination, so the batteries last longer, additionally there is less surface for the electrolite to evaporate since it's trapped in the mat. So... no filling, or water loss. Just better marine batteries. They also hold their current better because the mat prevents sulphication in idle batteries, they are extensivly used by the emergency and reserve power industry. For my application.... I'm now looking outside the marine market all together. There a number of manufacturers that make AGM's for high draw use in electric wheelchairs in my size range. I was hot on the ub12550 made by universal (too hard to find out here) I now like the mpl55-12. Several people make them including B&B (local) B&B recomends it for marine use as well as wheel chairs the stats are great. According to an independent site. "The MPL series is specificly designed for high rate usage, and enhanced floating life which is ideal for UPS (emergency, power sytems), marine, Telecom, and other high rate heavy duty applications. The cranking and reserve capacity of the MPL series meet the demand of marine applications" Sounds good to me.. The closest thing West Marine has to it is a U1 The MPL has 23 more amp hours 55 to 32, it weighs fifteen pounds more, which means more lead (which translates to longer life) more forgiveing on charging (accepts up to sixteen volts) and costs more then 20 bucks less. 53 bucks compaired to 79 at West. Now I just got to find a location to pick one up. Thanks again for the input. If anybody knows of a good outlet for MPL's please post the info. Thanks Jim [ Next Thread | Previous Thread | Next Message | Previous Message ]