2V batteries with 4 bolt connetion between batteries - how to connect the cabel?

[Roil]

Well I can figure out some, but not all.

Can you translate?

1st picture:

Mål=Measye
vekt=weight
Lengde= Length
Bredde=With
Høyde=High
Vekt=Weight


2nd:
Ladecurve=Charging curve
Selcutladning = discharge
Batterispenning kontra ladetilstand= Volt versus SOC
Utladnings karakteristikk= Øøøh - Discharge characteristics
Lade=charge
Spenning= voltage
Strøm=current
Gjenværende kapasitet = SOC
Lagringstid= Storage (months)
Timer=hours

3rd:
Antall syklingskurver i forhold til utladning= Number of total cycles reløated to discharge level

[inetdog]

Timer=hours

3rd:
Antall syklingskurver i forhold til utladning= Number of total cycles reløated to discharge level

The third picture is the one which answers your question.
These appear to be true Deep Cycle batteries.
One point on the graph shows that it will take 2200 cycles of 20% depth of discharge before the capacity of the battery is reduced to 80% of its original level.
Based on your use pattern that would be good for more years than the shelf life of the battery.
But at close to 100% discharge you would get only about 100 cycles.
This assumes that the batteries were new when you got them.

The unknown is what the current condition of the batteries is. If they were in standby use for emergencies or used to level off the output of a generator which is run intermittently AND they were not left for too many months without charging during the decommissioning and sale process, then they should be OK. (The self-discharge curve shows that at 30C it would take more than 10 months to go from 100% charge to 50% charge, so that makes them more likely to still be in good condition.)

The best way to estimate their current condition would be to fully charge one or more of them (long Absorb but not Equalize) and do a controlled load test to determine their capacity.

If I have missed any important points, I hope that Dereck will correct me or fill in the rest.

[Sunking]

If I have missed any important points, I hope that Dereck will correct me or fill in the rest.

No you pretty much got it. Only two things I can add is DOD vs Cycles is usually way over stated more like 50% of what is listed. The big question is what shape are they in which is unknown.

As far as cabling goes by th every design is intended to use buss bars like I shown in a pic and the reason is the very high currents involved. That is not to say you could not use cable, but could run into problems without using proper hydralic crimping tools, and proper torque wrenches. Jus tone loose connection of bad crimp = meltdown.

[inetdog]

No you pretty much got it. Only two things I can add is DOD vs Cycles is usually way over stated more like 50% of what is listed. The big question is what shape are they in which is unknown.

As far as cabling goes by th every design is intended to use buss bars like I shown in a pic and the reason is the very high currents involved. That is not to say you could not use cable, but could run into problems without using proper hydralic crimping tools, and proper torque wrenches. Jus tone loose connection of bad crimp = meltdown.

It looks like the four cells (in parallel inside) each 2 volt battery have no internal connections. Is that correct?
This means that Roil really has four 2 volt cells almost in parallel, and with the wiring you show actually four separate series strings connected only at the output bars. So equal resistance of all of the manufactured wire interconnections becomes very important.
The advantage that I see of the four cells in one battery over four separate cells is that they will necessarily be of the same age and initial constructionn and be at the same temperature within each case.
If you had a smaller number to use or wanted a higher bank voltage, could you choose to connect the cells in each battery in series, or would there be a problem (other than length of wire) that prevents that?

I would hope that the interconnects that came with the bank were well constructed, with the sort of quality control that one would expect for an oil platform (not operated by BP ) But Roil will have to manufacture some sort of bus bar to join the four leads at the ends together.
Would you suggest trying to replace the eight end leads with two busbars to get rid of two extra interconnects, or just wire the existing output leads to external bus bars?
It looks like it might be an interesting job to fabricate something to connect to those insulation-shielded wire ends.

[Sunking]

It looks like the four cells (in parallel inside) each 2 volt battery have no internal connections. Is that correct?

What I am seeing in one of his close up pictures in post #4 is two individual 2 volt cells in a common jar. Each cell has 2 pos and 2 neg battery post. If you go look at my pix each 2 volt cell has 3 pos and 3 neg post. Post count coupled with large mating surface = High Current capability both in charge and discharge.

In my experience when you see post like they are intended to us buss bars for inter cell connetions and term plates for load side connections. The Term Plate are large to accommodate multiple 2-hole compression connectors of large cable like 250, 500, or 750 MCM. Again look at my pix as it gives you a pretty good indication of what I am talking about.

[SunEagle]

It looks like the four cells (in parallel inside) each 2 volt battery have no internal connections. Is that correct?
This means that Roil really has four 2 volt cells almost in parallel, and with the wiring you show actually four separate series strings connected only at the output bars. So equal resistance of all of the manufactured wire interconnections becomes very important.
The advantage that I see of the four cells in one battery over four separate cells is that they will necessarily be of the same age and initial constructionn and be at the same temperature within each case.
If you had a smaller number to use or wanted a higher bank voltage, could you choose to connect the cells in each battery in series, or would there be a problem (other than length of wire) that prevents that?

I would hope that the interconnects that came with the bank were well constructed, with the sort of quality control that one would expect for an oil platform (not operated by BP ) But Roil will have to manufacture some sort of bus bar to join the four leads at the ends together.
Would you suggest trying to replace the eight end leads with two busbars to get rid of two extra interconnects, or just wire the existing output leads to external bus bars?
It looks like it might be an interesting job to fabricate something to connect to those insulation-shielded wire ends.

Either that or because of the high amperage the batteries give you the opportunity to have 4 conductors for each battery pole instead of 1 to allow you to reduce the cable size for the series connection.

[Roil]

The unknown is what the current condition of the batteries is. If they were in standby use for emergencies or used to level off the output of a generator which is run intermittently AND they were not left for too many months without charging during the decommissioning and sale process, then they should be OK. (The self-discharge curve shows that at 30C it would take more than 10 months to go from 100% charge to 50% charge, so that makes them more likely to still be in good condition.)

They where a part of a larger set used to supply power to a foghorn consequently being mainly standby. To my knowledge they have been stored for almost two years and are currently at 2.08V indicating charge state of approx 45% SOC. I assume they have been stored rather cold in the area of 10C-15C - max 20C and the SOC of 45% can then be correct.

curver2.JPG

curver.JPG

[Sunking]

They where a part of a larger set used to supply power to a foghorn consequently being mainly standby. To my knowledge they have been stored for almost two years and are currently at 2.08V indicating charge state of approx 45% SOC. I assume they have been stored rather cold in the area of 10C-15C - max 20C and the SOC of 45% can then be correct.

YOu need to locate the manual and see what they recommend of Condition Charge aka Equalization. But get them charged up ASAP. Cold storage was a good thing.

[Roil]

YOu need to locate the manual and see what they recommend of Condition Charge aka Equalization. But get them charged up ASAP. Cold storage was a good thing.

Yes indeed - I just need to agree with you and myself on how to connect the cable

Here are a specsheet I found - can you guys access this?

https://www.evernote.com/shard/s55/res/1edba11b-b8d5-4ea4-98af-8f50ffc31f0e.pdf?search=getek

Edit: Not.... Suntek3.pdf - sorry for the MegaBytes

Suntek2.JPG

[Roil]

It looks like the four cells (in parallel inside) each 2 volt battery have no internal connections. Is that correct?
This means that Roil really has four 2 volt cells almost in parallel, and with the wiring you show actually four separate series strings connected only at the output bars. So equal resistance of all of the manufactured wire interconnections becomes very important.
The advantage that I see of the four cells in one battery over four separate cells is that they will necessarily be of the same age and initial constructionn and be at the same temperature within each case.
If you had a smaller number to use or wanted a higher bank voltage, could you choose to connect the cells in each battery in series, or would there be a problem (other than length of wire) that prevents that?

I would hope that the interconnects that came with the bank were well constructed, with the sort of quality control that one would expect for an oil platform (not operated by BP ) But Roil will have to manufacture some sort of bus bar to join the four leads at the ends together.
Would you suggest trying to replace the eight end leads with two busbars to get rid of two extra interconnects, or just wire the existing output leads to external bus bars?
It looks like it might be an interesting job to fabricate something to connect to those insulation-shielded wire ends.

I must admit I assumed that this was one big 2V cell. When I measured the individual batteries I got variances in this range:

1. 2,079
2. 2,075
3. 2,073
4. 2,075
5. 2,068
6. 2,073
7. 2,076
8. 2,076
9. 2,073
10. 2,077
11. 2,072
12. 2,064
13. 2,079

Yes - I have got 13 of them

When I measure between each of the four different post of each cell i get no difference at all, not even of the third digit. .00X


The interconnects do look and feel of very high quality probably guided by the oil industry safety regulation. Each end is made of 1/2" thick copperplate, and the short cabel is probably 70mm2 (not sure what that is in DWG)

[Roil]

No you pretty much got it. Only two things I can add is DOD vs Cycles is usually way over stated more like 50% of what is listed.

By over stated do you mean that the number of expected cycles is only half of what these manufacturers promise?

As far as cabling goes by the very design is intended to use buss bars like I shown in a pic and the reason is the very high currents involved. That is not to say you could not use cable, but could run into problems without using proper hydralic crimping tools, and proper torque wrenches. Jus tone loose connection of bad crimp = meltdown.

Again I agree with the buss bar statements. Would it be fair to say that if the cables is high quality they can well be good enough?

Can a way to avoid "meltdown" be to check each one of them from any heat buildup during heavy charging or discharge?

[Sunking]

Yes indeed - I just need to agree with you and myself on how to connect the cable

The inter cells look OK. But you are going to have to figure out Term Plates fro permanent installation. Something made from 1/4-inch copper buss bar material and insulated phenolic or fiber glass material for support.

Take this warning very serious. If you short the battery out, it will explode into a ball of hot plasma that will vaporize skin and bone into ash. OK? I care about your safety.

[Sunking]

I must admit I assumed that this was one big 2V cell. When I measured the individual batteries I got variances in this range:

1. 2,079
2. 2,075
3. 2,073
4. 2,075
5. 2,068
6. 2,073
7. 2,076
8. 2,076
9. 2,073
10. 2,077
11. 2,072
12. 2,064
13. 2,079

Yes - I have got 13 of them

13 is unlucky and unless you have a special charge controller is no use to you other than replacing a weak battery.

The interconnects do look and feel of very high quality probably guided by the oil industry safety regulation. Each end is made of 1/2" thick copperplate, and the short cabel is probably 70mm2 (not sure what that is in DWG)

Sounds good to go.

[Sunking]

By over stated do you mean that the number of expected cycles is only half of what these manufacturers promise?

Yes. Only expect 50 to 60% of what is claimed.

Again I agree with the buss bar statements. Would it be fair to say that if the cables is high quality they can well be good enough?

I think so

Can a way to avoid "meltdown" be to check each one of them from any heat buildup during heavy charging or discharge?

Well that is a good after thought as you ramp up demand. More importantly is installation details making sure all connections use a good quality battery grease, proper quality compression tooling and installation technique, and using a torque wrench set to the proper torque per manufactures listing. ATTENTION TO DETAILS IS CRITICAL in your application. Your batteries are MEAN and will NOT tolerate any mistakes. One short circuit will vaporize steel and copper and the PLASMA gas will turn skin and bone to ash. You will not even feel the pain. UNDERSTAND?

[inetdog]

Yes. Only expect 50 to 60% of what is claimed.

I think so

Well that is a good after thought as you ramp up demand. More importantly is installation details making sure all connections use a good quality battery grease, proper quality compression tooling and installation technique, and using a torque wrench set to the proper torque per manufactures listing. ATTENTION TO DETAILS IS CRITICAL in your application. Your batteries are MEAN and will NOT tolerate any mistakes. One short circuit will vaporize steel and copper and the PLASMA gas will turn skin and bone to ash. You will not even feel the pain. UNDERSTAND?

One other thing you need to keep firmly in mind, especially if you mount the batteries with the terminals on top, is that any tool you use that is long enough to reach from one terminal to another needs to be insulated or handled very carefully. A wrench dropped between two battery terminals may end up melting like a fuse, only more violently, or just sitting there red hot until you figure out how to break it loose. (Better to just go to a safe distance and wait in most cases. The key is to plan ahead what you would do in the event of an accident instead of just reacting when it happens. Kind of like training yourself not to try to catch a sharp heavy knife when you drop it. )