VRLA Powerware battery

[Toad64]

I posted this in another thread but thought i might have better luck here since i was wanting to pick these up this weekend.

I was wondering if anyone thought these would be a good battery for a boat?

http://oklahomacity.craigslist.org/boa/2838981601.html

when i talked to the guy about them he said they where for back up power for big companies and they cycled them out every 2 years to keep them fresh. they have 550 cca, weight 70 lbs, are VRLA glass mat, and are good for 260 cycles so they are designed for 10 yrs of service. he said he as alot of calls from people wanting them for boats. he could not tell me what the AH would be. When I looked up the specs i could not make heads or tales of what the AH would be.


CONSTANT POWER DISCHARGE CHARACTERISTICS: WATTS/CELL (77?F, 25?C)
End point volts/cell 5 min 10 min 15 min 20 min 30 min 40 min 45 min 50 min 60 min 90 min
1.85V 336 276 235 202 156 127 116 106 92 67
1.80V 388 300 249 212 163 134 123 113 97 70
1.75V 436 326 263 221 171 139 130 117 100 73
1.70V 480 350 274 231 177 144 132 121 103 76
1.67V 506 361 283 236 180 146 134 123 106 78
1.60V 559 384 298 246 185 148 137 127 108 81
All mentioned values are average values per battery per cell.
Tolerance: X <6 min (+15% ~ -15%), 6 min X < 10 min (+12%~ -12%), 10 min X < 60 min (+8% ~ -8%), X 60 min (+5% ~ -5%)

I thought they could not be that bad of a battery?

 

[Silvertip]

Re: VRLA Powerware battery

Batteries like this are commonly used as backup power sources for telecom installations, emergency lighting systems and similar applications. They are not especially large batteries and are typically installed in groups of four to provide -48 volts for the electronics in these installations. They are designed for long life at "float conditions" since during the scheduled replacement cycle they may never have been deeply discharged. I would not use them on a boat but they would be ok for a low current emergency backup system.

 

[tx1961whaler]

Re: VRLA Powerware battery

You could use them for a small 2-cylinder motor starter. I wouldn't want to try to pull 400 amps surge out of one too many times for any larger starter, nor would I cycle them too deeply, or attach to an unregulated stator/rectifier. I have used them to both start my 40 as well as run lights for night fishing. I have bunches of them around work and snag ones that are past their expiration date or cycle time.
Like Silvertip said, these things are normally wired up as 48 volt block that is always in parallel with the equipment load after the rectifier rack, and are held at 51-52 volts all of the time. The AC goes off, and these thing are there to provide power until the generator comes on.

 

[Toad64]

Re: VRLA Powerware battery

Thank you. I will not be using these and get a normal battery.