100 AH Lithium by the numbers

[yupitsme]

Just a cheap'o 100 AH lithium w/BT 100ah Lithium Test
Date:	5/6/2024
Initial Pre-test readings
SOC:	100%
Total Voltage:	14.32
Capacity:	105
Avg Cell:	3.59
Temp.	N/R
Elapsed Time - (hh:mm:ss)	SOC	Total Volts	Amp Draw	Remaining Capacity(AH)	Estimated Run Time(hh:mm:ss)	Power (watts used)	Battery Temp(F)
0:00:01	100	13.87	58.54	104.63	1:51:00	N/R	N/R
0:07:00	92	12.92	58.54	96.19	1:37:00	N/R	N/R
0:15:00	84	12.91	58.92	88.11	1:29:00	N/R	N/R
0:25:00	75	12.89	58.92	77.96	1:19:00	N/R	N/R
0:40:00	60	12.85	58.73	62.91	1:04:00	N/R	N/R
0:50:00	52	12.82	58.83	54.14	0:54:39	N/R	N/R
1:00:00	42	12.78	59.7	44.03	0:44:09	N/R	N/R
1:10:00	33	12.72	59.41	34.12	0:34:18	N/R	91.94
1:25:00	18	12.56	60.61	18.97	0:18:50	N/R	93.56
1:35:00	9	12.37	62.03	9.15	0:08:47	N/R	95
1:40:00	4	11.61	62.41	3.57	0:03:22	N/R	95.9
1:42:00	0	11.46	N/R*	N/R*	N/R*	N/R*	96.26
.
.
Total Run Time was 1 hour 42 minutes. App had said 1hr 50 mins. at the beginning. 8 min. discrepancy. Not bad in my books. For this test I used a Milwaukee heat gun on low setting which produced ~59amp draw. High setting on the heat gun created a 116 Amp draw. The battery is rated for 100 amp continuous draw. N/R - Not Recorded, N/R* - No Reading

[yam911]

Thanks for the report.

Seems to be doing what they said it will do. Amps and amp/hours

Is this the first of the promised 15,000 cycles? You are going to have to step up the pace to get all 15,000 done before I depart this place.

[yam911]

Can you document the charging of the battery now that you have documented the discharge?

[yupitsme]

Can you document the charging of the battery now that you have documented the discharge?

Actually.... It's cycle #4

Yes, can document the charging cycle. Naturally it takes longer. In the beginning my NOCO GenPro 10x4 is hitting it with 9.02-9.07 amps. Later in the charge cycle I've seen as high as 9.75 amps.

[yam911]

Do you have any plans to let the alternator charge the battery?

[Bass in the grass]

Do you have any plans to let the alternator charge the battery?

I’m curious why you keep asking or thinking that it won’t fully charge a battery? Is there a reason why you think it won’t?

[goodman_fishing]

Thanks for the report.

Seems to be doing what they said it will do. Amps and amp/hours

Is this the first of the promised 15,000 cycles? You are going to have to step up the pace to get all 15,000 done before I depart this place.

Depth of discharge (DOD) must be factored in to cycle life.

When you look at cycle life it should say something like "4,000 cycles @ 100% DOD". If it doesn't, the cycle number alone doesn't tell you anything.

Examples
4,000 cycles @ 100% DOD (Discharging 100% -> 0% is 1 cycle. Charging from 0% to 100% is 1 cycle)
6,000 cycles @ 80% DOD
15,000 cycles @ 60% DOD


You can see how it scales with DOD and how that may play into sizing of your battery.

[yam911]

Are you the guy that has a device that will apply a load to a battery that will maintain a constant current even though the voltage drops as the SOC drops?

[yam911]

Depth of discharge (DOD) must be factored in to cycle life.

Good point.

[yupitsme]

Do you have any plans to let the alternator charge the battery?

Yes... That's the reason for the adjustable VSR.

https://www.amazon.com/gp/product/B0...0?ie=UTF8&th=1

The first two hours logged on the battery were with it in the boat. The app showed an amp draw of 9.07 amps for all my electronics. My testing had showed it closer to 10amps. My clamp meter came up with a 10.75 amp reading. In one case the 100 AH wouldn't make a tournament day. In another it would - but just barely. So I'm employing the VSR to remove any doubt. Supposedly with the programmable VSR I can select which battery I'm applying the programming to. With my old Yandina Combiner 100, when the VSR circuit was closed and the voltages stabilized, the Lithium held steady at 13.2v. My AGM cranking battery held steady at 13.1v. Interestingly when I applied a load to the AGM, cockpit and NAV lights, the app showed additional amp draw on the lithium. Even though the Yandina stated a cut-out, open circuit, when the voltage hit 13.3v that did not happen in my case. Granted the Combiner 100 was not their lithium production model so I'm not complaining.

If possible I'm setting the AGM cut-in value at 13.8v. Even if I can not direct that towards the AGM 13.8v on either, AGM or Lithium, circuit will only be at 13.8v because the engine is running. Yeah, the Lithium will initially be above that but only until a load is applied. The programmable VSR also provides the ability to implement cut-in/cut-out delays from 1-60 seconds. That "should" prevent the circuit from closing while the load is equalizing, more or less, between the AGM and the Lithium.

DOD and cycle life. If this configuration preforms as planned how does that impact cycle life? It seems as if cycle life is a measurement of power consumed. So if the DOD doesn't actually drop that much due to constant/intermittent charging it seems cycle life would still reflect power consumed - if that makes any sense. If you charged the lithium when it hit 50% SOC twice or charged the lithium once when the SOC hit 0% the net results on life cycles would be the same.


It will be interesting to see how the cycles respond to constant intermittent charging. Thus far in my testing I've pulled the SOC down to 8, 7, 5, and 0 percent. In each case it's been treated as a full cycle. Thus far I've haven't seen a way to break cycles down by DOD.

[BigFishSteve]

Very interesting. Thanks for that.

[JK9027]

That's over my head. 150 charges year for 5 years is 750 cycles... I'll be able to live with that, if I'm so lucky