Alternator Size with LiFePo4

[newhaul]

Originally Posted by rgleason

Newhaul,, A perfectly reasonable question.

1. I did not expect the quote to be that much. I have contacted 5 prototyping and local milling shops who support digital files.
2. I did do some adjustment to the load side expectations and realized that I am going to want some leeway in output for these loads (I may have had them a little different in the prior post):

- Charge LFP 200a x .35C = 70a
- Power DC Panel = 15a Nav, lights etc.
- Eutectic Refrigeration =10a freeze eutecticd. 10 extra

Total = 70a LFP + 15a DC Panel + 10a refrig = 95a Engine run morning and evening motoring for 0.5 to 2 hrs
I also hope to have a little extra in case my estimates are proven wrong or I decide later to get a bigger battery.
I do want good low rpm performance and may just get the Altmount 5.24" sheave.

I am trying to address the sheave cost and manufacturing before getting the alternator.

Ok now you are way over on the refrigerator estimate. Your actual (not knowing exactly what you have) i would estimate to be about 30ah per day 90% directly off the solar in the afternoon when the bank is fully charged. I ran a cool blue system on my spencer. It used a total of 38 ah per day ( monthly averaged) most of that was directly off of the solar ( 200 watts on hard dodger)

If your nav lights are drawing 15 amps then that's the first place to spend money.
Convert as much of your lighting to led.
I had the spencer down to under 50ah a day comfortably while at anchor or underway if I didn't need the autohelm.

[rgleason]

Newhaul,

Yes I do have LED lights , chart plotter and radar, instruments that may be running during charging.

The refrigerator takes 80 amps the first day after that more like 30-35a. It is a eutectic system so we try to run it on full (7a) normally 5.5-6a, plus we run the domestic h20 cooling pump (1a) for faster draw down while engine is running and going in and out of harbor (.5hr-2hr/day) plus any light wind motoring.
The 7a+1a for refrigerator during motoring I called 10a needed for alt output.

Perhaps I could reduce needed alt output by 10a.

I saw (2) flex sun power 100w weighing 5 lbs for about $175 and was tempted. The rigid version Renogy 100w is more efficient and smaller allready has a frame but weighs 15lb which is 30lb on the stern.Do you think this would be enough?

[newhaul]

Originally Posted by rgleason

Newhaul,

Yes I do have LED lights , chart plotter and radar, instruments that may be running during charging.

The refrigerator takes 80 amps the first day after that more like 30-35a. It is a eutectic system so we try to run it on full (7a) normally 5.5-6a, plus we run the domestic h20 cooling pump (1a) for faster draw down while engine is running and going in and out of harbor (.5hr-2hr/day) plus any light wind motoring.
The 7a+1a for refrigerator during motoring I called 10a needed for alt output.

Perhaps I could reduce needed alt output by 10a.

I saw (2) flex sun power 100w weighing 5 lbs for about $175 and was tempted. The rigid version Renogy 100w is more efficient and smaller allready has a frame but weighs 15lb which is 30lb on the stern.Do you think this would be enough?

I was running a pair of windy nation 100 watt panels on the spencer. And it was enough 99% of the time
New owner is also happy with the setup he just changed to an MPPT now the panels have not failed to cover the power usage .

You have seen my current setup ( panels) and they are more than enough except now ( dead of winter.) Since I added the diesel forced air furnace . Have had to deploy the 2 100 watt flex panels.
But I sail in winter as well

[rgleason]

@evm1024
@Q Xopa

Regarding the Delco Remy 28SI shaft. I need the knowledge of Delco 28SI Alternator owners:

1. How long is the sheave shaft from the heavy ring to the start of thread? Is it about 35.3mm / 1.39 inches (measured from some online diagrams) ?
2. Is the shaft tapered slightly? -or is it exactly 7/8" (22.24mm) dia for the whole length?
3. Is there a keyway or set screw in the sheave? - I don't see a keyway or set screw.
4. What keeps the sheave from turning on the shaft? - Is it compression against the heavy inside compression washer shown in the videos, by torquing the Nut? -or is it dues to a sloping shaft diameter?

I think I have found a 2" J10 x 7/8" sheave that might work for the Delco Remy 28SI 8600318 160 amp Alternator. It consists of

1. Sheave 10J200JA 2" Sheave with a 22.23mm or 7/8" shaft https://www.bbman.com/catalog/product/10J200JA $35
2. Bushing JAx7/8 bushing for 2" Sheave https://www.bbman.com/catalog/product/JAx7_8 $7

This is a 1" thick sheave instead of the, approximate 1.39" of the typical pulley that fits on this alternator. Would I be able to make up the difference with the right sized washers?

Originally Posted by newhaul

100 watt panels...was enough 99% of the time

Newhaul, Thanks, that's helpful.

[evm1024]

I will have to check on mine. But going from memory I do not recall a keyway. The pulley was just a tight fit (perhaps a press fit) with a properly torqued nut.

When I get to the boat this weekend...

[Q Xopa]

Originally Posted by rgleason

@evm1024
@Q Xopa

Regarding the Delco Remy 28SI shaft. I need the knowledge of Delco 28SI Alternator owners:

1. How long is the sheave shaft from the heavy ring to the start of thread? Is it about 35.3mm / 1.39 inches (measured from some online diagrams) ?
2. Is the shaft tapered slightly? -or is it exactly 7/8" (22.24mm) dia for the whole length?
3. Is there a keyway or set screw in the sheave? - I don't see a keyway or set screw.
4. What keeps the sheave from turning on the shaft? - Is it compression against the heavy inside compression washer shown in the videos, by torquing the Nut? -or is it dues to a sloping shaft diameter?

I think I have found a 2" J10 x 7/8" sheave that might work for the Delco Remy 28SI 8600318 160 amp Alternator. It consists of

1. Sheave 10J200JA 2" Sheave with a 22.23mm or 7/8" shaft https://www.bbman.com/catalog/product/10J200JA $35
2. Bushing JAx7/8 bushing for 2" Sheave https://www.bbman.com/catalog/product/JAx7_8 $7

This is a 1" thick sheave instead of the, approximate 1.39" of the typical pulley that fits on this alternator. Would I be able to make up the difference with the right sized washers?


Newhaul, Thanks, that's helpful.

Hi all,

Im no expert and going from my memory (which is dubious at best), but yes the 28si, ie large frame Alternators have 7/8" straight shafts.

As for some of your other more specific shaft lengths and sheave thicknesses, I will have to check. Luckily, I have actually just made it back to my boat in this last week since last Feb. So I'm generally 'putzing' around the last bit on my new engine install and synthetic standing rigging.

I will try and get some of the measurements you are asking for in the next day or so and report back.

I can also add that there is no key way, or taper on the shaft, and as you say the pulley is 'fixed' to the shaft by compression of torquing the nut. Mine has an Allen key, ie internal hex in the end of the shaft so the shaft can be held when torquing the pulley nut.

Some greater experts may be able to comment and possibly correct me. But I would say that a narrower pulley wont matter providing you can get compression on it from the nut. If you cant I would, as you suggest, get a washer under the nut to get the pulley squeezed up.

Of course, if you need a washer, or spacer, my thinking is get a nice fitting one, particularly with a snugish 7/8" hole in it. Maybe you might want to get this machined up nice on a lathe? This is typically were many would just grab any ol close enough washer, hmmm gash.

Also this may effect your pulley belt alignments. But I did that on mine after this step, so in this case you will get that right.

Any other details you want let me know.

Good luck.

[rgleason]

Thanks EVM1024.

While looking for J10 sheaves I found this 1.9" diameter x 7/8" sheave with a set screw. I don't believe it is quite as thick (shaft length) as the 1.38" thick (along shaft) sheaves that I found for 28SI Pulleys, but is 2" diameter

Attached are some 28SI Pulleys showing typical J8 sheave dimensions (2.3" and 2.4" diameter).
The inset (9mm) for the Nut and a washer side, is shown. There is a corresponding bump (9mm) on the other side that goes against the inside compression washer, for some reason. Is this bump really needed?

I think these 2.3 and 2.4" diameter sheaves are too big to allow the alternator to cool itself at low engine rpm, and they tend towards lower output at low rpm.
5.24" Altmount/2.4" alt Altmount = 2.18 ratio x 850 eng rpm =1,853 alt rpm
5.5" custom crank/2.4" alt = 2.3 ratio x 850 eng rpm =1,955 alt rpm
5.24 altmount/2.0" alt = 2.62 ratio x 850 eng rpm = 2227 alt rpm
5.5" custom crank/2.0" alt = 2.75 ratio x 850 eng rpm = 2,337 alt rpm
Then look out the hot continuous output curve or deduct at least 20% from the cold output curve.

[Q Xopa]

Originally Posted by rgleason

Thanks EVM1024. While looking for J10 sheaves I found this 1.9" diameter x 7/8" sheave that has a set screw. I don't believe it is quite as thick as the 1.38" that I found for 28SI Pulleys.
Attached is a jpg showing the dimensions of one of these pulleys.

Ah ok good. Mine doesnt have a set screw, but I guess there are apparently different methods of 'fixing' the sheave to the shaft.

I guess if you were worried about the pulley slipping on the shaft you could add some Loctite bearing retainer as well. But I dont think it is normally an issue.

[rgleason]

Originally Posted by Q Xopa

Hi all,
Im no expert and going from my memory (which is dubious at best), but yes the 28si, ie large frame Alternators have 7/8" straight shafts.
...
Any other details you want let me know.
Good luck.

That's very helpful, understanding the compression and the need to be the right thickness. Thank you.

[newhaul]

I know this is not about alternators but it is a great review vid of cheap lfp cells

https://youtu.be/3U4ZfQ_IToI

[rgleason]

Originally Posted by newhaul

I know this is not about alternators but it is a great review vid of cheap lfp cells

https://youtu.be/3U4ZfQ_IToI

Is it acceptable to have them on their side? I could slip these into the removed drawer opening sideways and then twist them to set in a strapped in location and then fasten the bus bars from the drawer opening. I would make a replacement drawer front that simply hooks in, with air vents and a fan if needed and keep the drawer intact for reuse in the future.


The other alternative is to keep them lying flat and try to slide them under the cabin sole and wire them up properly using the busbar in series.

- --- --- --- +

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These batteries would only be 2.8" high which might very well fit under the cabin sole on top of the keel water tank. Very good clearance price. I'd probably get a Daly WP single or dual port 200ah BMS.

[newhaul]

There are many that will say yes but myself I would prefer the prismatic cells to be hanging as opposed to laying on their sides .

[rgleason]

Originally Posted by Q Xopa

Hi all,

I can also add that there is no key way, or taper on the shaft, and as you say the pulley is 'fixed' to the shaft by compression of torquing the nut. Mine has an Allen key, ie internal hex in the end of the shaft so the shaft can be held when torquing the pulley nut.

..I would say that a narrower pulley wont matter providing you can get compression on it from the nut. If you cant I would, as you suggest, get a washer under the nut to get the pulley squeezed up.

..get a nice fitting one, particularly with a snugish 7/8" hole in it. ..get this machined up nice on a lathe?

@Q Xopa

I finally purchased a genuine Delco Remy and it has arrived. The smooth shaft to the start of the threads measures about 1 3/8" long, and I finally found a pulley on the Delco dimension diagram (upper right in the attachment) that showed a double sheave with a 33.5mm (1.32") distance to the inner surface of the outer washer and the nut/washer recess. The recess is shown with a minimum diameter of 35.6mm.

Assuming I get a B&B alternator sheave (see this thread: J10 x 2: dia sheave
"The sales engineer confirmed that compressing this bushing with 90 psi torque will be okay because it is a steel bushing. J10 x 2" dia (10J200JA) Sheave $36.23 with JA x 7/8" bushing $7.50" The bushing is 1" thick.

So I will need about a .32"+ thick washer with tight 7/8" hole to clamp the alternator sheave.


This Tech Tip: Alt sheave installation: https://www.delcoremy.com/the-latest...co-remy-24sitm States "Proper installation of the pulley on a Delco Remy 24SI and 28SI ensures that the product will perform as promised. Unfortunately, damaged products are returned to Remy as a result of improper pulley installation."

and the bottom of the instructions in the box state "...keep the alternator shaft horizontal and do not apply any to the end of the shaft. Internal damage may occur if the shaft is pushed back and turned..."

Does anyone know what "Internal damage may occur"?

Attached is the dimension diagram

[rgleason]

Evm1024 Converting Delco 28SI to External Regulation Post #1
Evm1024 Conversion Details
Evm1024 Derating from 200a to 120a Post #25
Q xopa Converting Delco 28SI Alternator to External Regulation
Q xopa Detail of mounting Post #45
Q xopa More photos of mounting Post #58
Q xopa Photo of Bracket details Post #64
Q xopa Adjustible Bracket Photo Post #72

rgleason Concept Drawing for 3YM30 and engine room photo
rgleason More detailed measurements
rgleason J10 x 2" Dia Pulley for 28SI shaft
rgleason Correct FLA size for Lithium-Hybrid combination
rgleason Serpentine Belt Advantages
rgleason Small Boat Electrical for Sail
rgleason Electrical Schematics Preliminary
rgleason Electrical Schematic Initial
I have not decided yet between LiFePo4 and Firefly. Firefly can be charged at .5C and resists sulfation.

[rgleason]

PRELIMINARY FiTTING on Yanmar 3YM30

Swung out somewhat to substantially clear connections from manifold.

FOOT ATTACHMENT

The alternator aft foot is placed hard against motor alternator bracket back surface and bolted (a bolt size spacer will be needed) and the sliding slug adjustment needs to be ground down for the existing bolt to work right.

A short slug with a hole will be needed in the front between the front alternator foot and the motor alternator bracket, seen in the Alignment1-overall.jpg.

ALIGNMENT

Several photos show the alignment.
Alternator is 1/8" off, so a washer with 7/8" hole x 3/8" thick will be placed inside the J10 sheave.
Hopefully this will line up with the J10 crank pulley.

ADJUSTABLE BRACKET

Needs to be bent and fabricated.

ADDITIONAL ITEMS NEEDED

Convert for external regulation
Extend system coolant hose to miss new belt and sheave
Idler pulley for coolant system belt.
Belt cover and brackets will be removed as the impede air flow anyway.

Photos of preliminary fitting below