Just getting started; Trojan T205 batteries

[tjspears]

I am just getting started planning for some backup capacity for when the local grid is down, this may expand to later to decrease our daily dependency on the grid or remove it entirely.

I am in the process of figuring out what we want to run, and how much power it will require.

I have a coworker that has two Trojan T205 batteries he is replacing. They are about 10 years old, were in stalled in his trailer. When new they were 210Ah 20hr. He is willing to let me have them for free, is there any reason I shouldn't take him up on this?

--James.

 

[Phssthpok]

Depending on how they were treated they could either be a lost cause (worst case scenario) or just about to begin ending their useable life (I hear 15 years is a good run for these). At 10 yrs old it's a gamble as to whether or not you'll get much use out of them, but as far as I know you won't HURT anything by hooking it up to dead battereis (unless it's a new and or prefectly good battery you're attaching). They just won't hold any useable charge for decent amount of time is all if they are in fact dead.

Also...are you sure they are T-205? I thought Trojan only had the T-105, and T-125 in that size range. The specs sound like a 105 to me.

[jimjjnn]

I would imagine that ten years may have those batteries at the end of their useful life. Others on the board here may have more info.

[scottsAI]

Hello James,

I have done (started) what you are doing. The system is four APC 3000 watt UPS.

Placed the UPS next to the fuse box, pulled the circuits from the panel, attached a 3 prong plug and plunged the circuits into the bank of UPS. The UPS has an auto transfer switch and battery charger built in! So far I have one of the 4 UPS connected. Need to do a little rewiring. Added four 30a circuits to power the UPS. The battery is 8 golf cart batteries. Total cost for everything $948.

If I'm careful the UPS should power the Fridge, lighting, small TV, and well pump for 2 days, 4 days if willing to kill the battery. Not good to discharge below 50%-80% You can find lots of advice on this issue.

When the power fails, the lights flicker, everything continues to run! The electric oven is not on it.

Nice feature of the UPS is I can control them from a computer. Plan is to have the SETI computers go down after 5 minutes, The UPS can tell the computers to shut down cleanly. Then the UPS shuts down. The UPS are left beeping, so I know the power is down (can shut it off). After 10 minutes two more UPS shut down. A laptop is controlling the final UPS. If the loads are not removed after 15 minutes the UPS decides nobody is home and shuts it off. The final UPS has the fridge on it. The fridge can ride out 24 hr without power. If on vacation, everything should be off, so the fridge should be able to run for several days as the only load. UPS shuts down only on dead battery. Food in fridge is not worth the cost of a new battery... Plan is to use my car to recharge battery during an extended power outage. Not very efficient, considering a generator. In twenty years, longest power outage was 2.5 days.

Cheap generators cost less up front and can run longer if you have the gas, 10 to 15 gal per day. The required transfer switch cost $250 so cost is now on par with above. Wife does not like the neighbors that run the generators all night long. Did not want to contribute to the noise pollution. Battery backup was the choice. Started with several 2000w 12v mod sin wave inverters. The charger and transfer switch made the system awkward. The charger was a fork lift charger, still would take couple days to charge 8 batteries. Then I realized the 6 UPS on my computers were just the ticket. Figured this out during a short power outage when my computers were running and nothing else.

The power efficiency of the UPS for light loads is less than the mod sin inverters. I tested out a 350w inverter had 12v 12aH battery with 43w load. Tested an APC 1000w UPS, same load, required two of the same batteries. Run time was the same:-( Most of the APC UPS 1000w and larger UPS are sin wave inverters so this may account for the difference in efficiency. Have not tested it with a mod sin UPS.

The UPS expects a sealed lead acid battery (SLA), the voltage is limited on this battery to 14.5v on the charge. A flooded battery is charged OK with 14.5v. But requires a proper finishing charge to be done every 3 months, whether discharged or not (so can use fork lift charger for something). A flooded battery will last longer than the SLA if taken care of. I suggest you to do some reading on lead acid batteries. Beware lots of miss information out there. When you read something ask your self if it makes since. Do not color it with what you want. If your efforts do not recover the T205, look into reverse charging them. Make sure you paint on a new pos and neg on the battery if you do or you will wish you had!

Have fun,

Scott.

[tjspears]

There are no other batteries yet, if I was to put out some $ for real batteries I would to a secondary system out in the barn for lights or to pump rainwater for the collection tank that is going in up to the garden.

I did pickup the Harbor Freight Solar kit for $170 yesterday (Thanks to whoever posted the 15% off coupon), this is all just a starting point and learning exercise.

Thanks,

--James.