Batteries on the way

[Sunking]

I knew instantly Sunking would be against them.

Against them? Not really, especially when it comes to Mike. Like myself, Mike is an engineer, did his homework, understands the physics, technical challenges, and economics. As you can read Mike's comments, you can tell he is nervous and not certain of his decision.

Mike,

What I am really curious about is the high internal resistance issues of NiFe and what will happen when you load them heavily on the inverter. I think you know where I am going with this. Let me know if the inverter trips off-line.

[Sunking]

since there apparently are no amercian mfgs, just rebuilders of the NiFe's from the 60's

There is a good reason no USA manufactures make them and why Edison never renewed the patent. Exide battery was the last manufacture in the USA and they discontinued production in mid 70's.

[Sunking]

Or I'll measure by weight.

It is a weight ratio.

[Mike90250]

Yes and no.

First you should never use an automotive hydrometer for batteries. Use a lab quality with temp correction.

Secondly alkaline SPG does not vary much during charge and discharge cycles, but gradually falls over a long period of time: When it falls to value of 1.160, it should be replaced. Alkaline SPG, unlike lead acid, is no indication of state of charge.

Didn't help much huh?

Well, it did, I was wondering if a Refractometer would work, and now that I know the range the cells are in, I can set the initial filling correctly. Or I'll measure by weight.

[Sunking]

Does a regular automotive battery hydrometer work with them ?

Yes and no.

First you should never use an automotive hydrometer for batteries. Use a lab quality with temp correction.

Secondly alkaline SPG does not vary much during charge and discharge cycles, but gradually falls over a long period of time: When it falls to value of 1.160, it should be replaced. Alkaline SPG, unlike lead acid, is no indication of state of charge.

Didn't help much huh?

[Mike90250]

So do I. Surrette can get you a replacement delivered in a week no questions asked so to speak.

China batteries?

Discussions at wind-sun re Surrette indicate otherwise.

yeah, Chi-Com batteries. well, our nations soul is in debt for a hundred years to them, just playing follow the leader, since there apparently are no amercian mfgs, just rebuilders of the NiFe's from the 60's

[Mike90250]

Does a regular automotive battery hydrometer work with them ? I didn't know if the electrolyte SG levels would be anywhere the same or not. I just ordered a scale to pre-measure the chemical for the cells.

As the batteries work, they heat up, and the volume increases, normal.

And, I sure hope that things do work, and that I dont end up *^$@%&@ here about a bad choice, or crappy parts.

[Sunking]

I sure hope I can disappoint you, and not kick myself.

So do I. Surrette can get you a replacement delivered in a week no questions asked so to speak.

China batteries?

[john p]

Mike im not sure if you have done the right thing or not . But I really like it that someone like you has done it so we can get to hear how it all goes in the future..I hope it goes well I have always liked them but cant justify buying them.
I knew instantly Sunking would be against them., I hope for your sake his reasons (which are mostly valid) dont turn out to have a unhappy ending for you..

GOOD LUCK WITH THEM.

[SteveC]

How did you come up with 854 AH @ 48 volt
The voltage stamped in the photo says 1.2V 600AH
So 40 in series gives you 48V but only 600AH

The manufacturer used the C/5 rate to label the batteries. The seller recommends using the C/100 rate. The difference between the 600 a-h on the cells and the 854 a-h, is due to that. Or so the written material with the batteries says...they feel the C/100 rate is more realistic for off-grid set-ups.

[SteveC]

What was your experience with watering them, enough of a reserve to not do it monthly?

As for discharge, I just need to run the water pump in some pre-dawn hours, that will bleed them down quick.

I've only been working with them for a couple weeks, so watering has not been an issue. I did add a little yesterday, about a half gallon total to ten cells. The instructions say to fill the cells with electrolyte only to the lower-limit mark for the initial charging sequences. I wondered why, and found that the level rises during these chargings. Mine rose about a half inch. After the initialization is complete, you add more electrolyte to get up to the higher level. What I did was put a piece of masking tape across the raised level of the fluid, marked the level with a pen, then added the water to keep the level at that mark. I have one more cycle to go through, then I'll top off the electrolyte.

I also bought one spare cell....

To discharge I hooked them up to my house loads and let them go down to about 10.5, the lower limit for the inverter and Sunfrost appliances. I boosted this process by running our well pump [fills a 2000 gal. cistern, the level of which I had intentionally allowed to drop] and other stuff like the vacuum cleaner, etc., with no charging hooked up to the bank [Outbacks turned off]. Our lighting is all 12 v., so from there I turned on all the lights and let them go for a couple days [had to stop myself constantly from turning them off as would happen to pass a switch after all these years]. That way I got them down to less than 5 v. for the bank. I have since been told that lowering the charge to about 8 or 8.5 volts is enough.

The problem was, at that point, and one I hadn't realized, the Outback stuff [MX60s and FM60s] won't come on til a higher voltage, someone tells me 10 v. but I am not sure. So I could not start the PV charging til I got the batteries up from their low. What I ended up doing was hooking up a car-battery trickle charger [in desperation] to see what would happen. Sure enough, this brought the voltage of the bank up high enough, after several hours, to turn on the Outbacks. I have 2700 w. array, so charging from that point is no big deal.

One more hint. ChangHong includes in the order a digital multimeter [instructions in Chinese, but the markings on the meter are English] and a hydrometer. This item was junk: the rubber parts did not seal at all to the glass tube and it was completely unusable. I happened to have a decent one around here. If you do not, I recommend to go get one. You probably already have one around, most battery users do. If you haven't used it in a while, test it to make sure it will draw and hold fluid, as the availability of one is essential to mixing up the electrolyte. By the way, it is not recommended to use a hydrometer which has previously been used in acid....

[Mike90250]

Mike personally I think you might have made a mistake. I look forward to you assessment 2 years down the road.

I know. Took a long time to decide. Surrett seems to be haveing issues with dud cells, Hawkers cost almost as much. At 2V 800A, the jugs are still manageable, not bonded together or anything, so I can move by hand.

I sure hope I can disappoint you, and not kick myself.

[Sunking]

Mike personally I think you might have made a mistake. I look forward to you assessment 2 years down the road.

[Mike90250]

The photo is a stock photo, they have a bunch of different capacitys (way too many I think) I've ordered 42, so I'll have a couple spares. The big job is the layout, I'll have to get some jumpers made - the factory interconnect buss bars don't allow for tiurning corners. and if I make 3 rows deep, too hard to water the back row.....

[Naptown]

The boat is loading this week. 48V, 854ah. That will be 2x the current size of the weak, used set in operation, and enough to run the house, farm pump, blowdryer[ATTACH=CONFIG]1275[/ATTACH], and microwave. From beutilityfree.com/Electric/Ni-Fe and now I see the Swiss have a Molten Salt/Nickel battery coming out too - zebra-battery and in another 5 years, there will be a better mousetrap. I'll get something while I can. Now to order 100 gal of distilled water, and some siphon tubing....

So I agonized long and hard over them, vs a forklift battery, and many other considerations. I'm willing to give up some efficiency (70% vs 80%) for a much longer overall lifetime and in winter, when running the genset, I'll be in the bottom 2/3 of capacity anyway, where they are more efficient. And they have a pretty large freeboard, so only watering every 2-3 months in summer. But they are less energy dense then lead acid, and will take up a much larger footprint in the battery shed. Still doing final layout tweaks.

How did you come up with 854 AH @ 48 volt
The voltage stamped in the photo says 1.2V 600AH
So 40 in series gives you 48V but only 600AH