| Author |
Message |
Dave Silva (Cypress)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 10, 2005 - 8:15 am: | |
I'm watching an auction for some 60 AMP 28V alternators, from a Bradley or a tank, will they be appropriate to charge 24V battery banks? |
Marc Bourget
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 10, 2005 - 10:00 am: | |
If the auction is Gov Liquidators, they will frequently have 28V Alternators up to 150, 200 and 400A (rare)
Be careful, they are frequently surplussed because a mounting tang has been broken off through a negligent/hurried installation attempt.
Depending on the size of your battery bank, you might benefit from a unit with more capacity than 60A
Onward and Upward |
Dave Silva (Cypress)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 10, 2005 - 10:11 am: | |
I'm doing backyard re-engineering with almost no money. I got a pile of 3000VA (2400 W) UPS' the same way. Some folks said they would not work as a fulltime inverter but with increased cooling they seem to work fine. Now I want to recharge the batteries from my van with a seconfd dedicated alternator.
I've also heard that MILSPEC performance is often very conservative due to operating conditions? So a 60 AMP alternator might deliver a lot more at more comfortable tempertures?
thanks |
kevin schooler (Sylverstone_pd4501864)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 10, 2005 - 2:18 pm: | |
i have a stretched triple axle dodge van.
the house battery bank uses (8) deep cycle rv type batteries in it.
charging those batteries is (4) 1400 va apc ups systems, (24 volt rail voltages) being fed by a beefy inverter (no idea on size, looks homemade, ham radio buddy supplied it)
basically, i set the ups systems, in software, to turn themselves off automatically. 3 of them at 1 minute after power fail, and 1 of them at 5 minutes after power fail. the 5 minute one runs the computer and navigation systems, etc.
basically, i get out of the rig and walk away, and 1 minute later all but 1 of the 110 systems shut down, and at 2 minutes the computer initiates shutdown, and at 5 minutes the last ups turns itself off.
works pretty well.
the multiple conversions bother me (alternator --> inverter --> ups --> batteries --> ups --> load, but i wanted the automation. a bigger ups and i could just charge the bank with a second alternator... (i can't this way because i can't figure out how to do it without the ups freaking out over the battery voltages)
i'm a big believer in "put in a second alternator for house loads" because a 90 amp chevy alternator is cheap, whereas anything over 150 usually isn't.
it's a trick i picked up from the high end car audio universe. company named critical maas used to make a dual output 500 amp per channel, external fan cooled regulators job that would fit in a honda...
-dd |
Dave Silva (Cypress)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 10, 2005 - 8:27 pm: | |
wow, i thought it was just me. Since I posted this the alternator on my van died. So now I'm thinking I may look at putting a 28 volt alt in it and find some way to provide 12V to the things that have ot have it (fuel pump)
Any ideas Kevin? |
kevin schooler (Sylverstone_pd4501864)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 10, 2005 - 8:35 pm: | |
bad luck day. someone hit mine in front of my house and caved in the side doors sometime last night. hit and run. :/
as for your van, i think everything in it is going to require 12v ...
-dd |
John Jewett (Jayjay)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 11, 2005 - 12:00 am: | |
J C Whitney has a 24/12 voltage reducer with a reasonable rating. JCW.Com IIRC. ...JJ |
Dave Silva (Cypress)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 14, 2005 - 9:15 pm: | |
Kevin,
Any idea how to get the UPS to come online without AC going to it? No matter how well charged the batteries are it must start out with AC before the inverter function will happen. I could use a cheap 400 Watt inverter to get it going but I'd love to figure out soemthing internal to te UPS that would be a bit more elegant.
Thanks |
kevin schooler (Sylverstone_pd4501864)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, October 15, 2005 - 9:43 am: | |
well, you can plug them into themselves usually...
at least, my apc's can.
are you using the rig to charge the batteries? or are you using the ups to do it?
-dd |
Dave Silva (Cypress)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, October 15, 2005 - 10:50 am: | |
I'm still messing around with charging options.
Two sets of batteries with overlapping wiring to charge in series at 12V and work in parallel at 24V. It's cumbersome but I have all the components, (bunch of relays)
Or find a way to add a 24V alternator to the van.
dave |