Charging four batteries with my new Victron BlueSmart IP65 charger

[Old Crow]

Hoo, boy, I'm not sure what to make of this.

I just bought a Victron BlueSmart 15-amp AC-to-DC charger. I tried it for the first time yesterday. I'm confused by the results.

I charged four batteries, three of them starter batteries in my vehicles and the other the house battery in my Transit. Three of the four went to float in about a half hour and the fourth went to float in 8 hours (see more detail below). Also: The app showed an incorrect vstart voltage for all of them and all went immediately to absorption phase though voltages were low enough on three of the four that the charger should have gone into bulk phase.

Note: I also have a Clore BA9 digital battery tester and I'll include some numbers from it below in case they're helpful.

Battery 1: 2014 Optima RedTop AGM-spiral starter battery. Start: Measured voltage 12.3, BA9 showed 55% SOC, 5 mΩ internal resistance. Victron Connect showed a vstart of 12.73 volts for the charger which went immediately to absorption, charged for 33 minutes at less than 1 amp before going to float. This morning, the tester shows that battery at 12.4v, 61% SOC, 5.62 mΩ. This was a poor charge.

Battery 2: 2021 Interstate 27M-EFB enhanced float deep cycle battery. Measured starting voltage 12.65 (no BA9 measurements on this one). Victron Connect showed vstart 13.6v and it charged at 14.4v/4a briefly and I saw it drop to 2a. Went to float in 30 minutes. This morning battery voltage is 12.77. This may be a reasonable charge-- a nearly-full battery topped off-- but it's hard to say.

Battery 3: 2019 Motorcraft Max conventional flooded starter battery. Measured starting voltage 12.36v, 10 mΩ internal resistance. VictronConnect showed vstart as 12.5v and went immediately to absorption. I saw 8 amps, 6, and 5.3 during the 30-minute charge. This morning the BA9 test says the battery is at 12.4v, 75% SOC, 7.79 mΩ resistance. This was a poor charge.

Battery 4: 2016 Duracell Ultra conventional flooded starter battery. Measured starting voltage 12.36v, 4.14 mΩ internal resistance. The charger went to 14.4v at 13A and as I checked from time to time I saw it going down. In fact the amperage drop was distinctive-- going down very, very slowly for a long time. It seemed like it would never end. The charger light was in absorption mode the whole time but the Connect app says it bulk-charged for 36 minutes. It also showed exactly 8 hours of absorption charge and exactly 8 hours of float charge before it went to Storage mode. This morning it tests 12.9v, 100% SOC, 3.35 mΩ. This appears to be an excellent charge.

Questions:

1. Anybody else with a Victron AC-to-DC charger seeing vstart voltages much higher than the voltage measured with a voltmeter or digital display?

2. Any idea why batteries 1 and 3 were charged so poorly? (Note: I believe I've seen this same thing happen with other chargers)

3. Any suggestions on how to trick the charger into charging better?



Edited 6/16 to add:

Another data point. Just tested batteries 1, 3, and 4 with a 130-amp load tester. All stayed well in the green with #1 and #3 at 11.0 volts and #4 at 11.8 volts on the 15-second test.

 

[Vic Harder]

fascinating. What are the "battery" settings you are using on the charger?

 

[Old Crow]

fascinating. What are the "battery" settings you are using on the charger?

Hi, Vic....

The Mode button on the charger allows selection of "Li-ion", "Recondition", "High (14.7v)", and "Normal (14.4v)"

I used High for Battery 1 (the Optima spiral) and Normal for the others (the flooded ones).

For the High mode, Bulk and Absorption are 14.7v, Float 13.8v, Storage 13.2v

For the Normal mode, Bulk and Absorption are 14.4v, Float 13.8v and Storage 13.2v.

These are the default values. I didn't change these defaults in the Advanced Configuration settings area of the app but here's what it shows on that screen (in High mode).

 

[Vic Harder]

Batteries 1 and 3 are the strange ones, from what I can see. #1 puzzles me the most. Are you sure the batteries are otherwise healthy, other than needing a charge?

 

[Beach]

Couple things; you have two different battery types here, AGM and FLA all from different manufacturers. Also the fact that one battery is 9 years old and others are of various ages. I would suspect some of the batteries are having sulfating issues which is affecting the charging. If you have added water to the FLA batteries there could be some degradation of the electrolyte solution. When you check the resting voltages how long had the batteries been disconnected from the charge?

 

[Old Crow]

OK, I believe you guys are right about the health of Battery 1. I have been a bit suspicious of it because of its age and finding over time that its normal resting voltage seems to sit lower. However, it was passing (and still passes) a load test and I've not seen any indication of a problem starting the car's engine. But this morning I did finally see a test result showing a bad battery (see below).

I tried two more charging cycles yesterday and they were interesting. The charger went into bulk mode this time. Both were only in bulk mode for almost exactly three minutes. It seemed odd the charger wasn't applying (or the battery wasn't accepting) much amperage... less than one amp.

Then the absorption charge was exactly 30 minutes-- which the manual says is the minimum absorption charge (maximum is 8 hours).

The other thing that tells me the battery isn't healthy is the BA9 battery tester. This morning it declared the battery bad. This is a conductance tester and it compares what it measures to the Cold Cranking Amps number I put in from the battery label. In this case it says the battery is capable of 543 CCA of its original 800 CCA and that translates into a 67% SOH (State of Health). The tester now consistently shows the word 'Bad' after (multiple) tests.

The 'Bad' assessment of course depends on how the battery is used. It's summer and that car has always started very easily so I might get away with putting off a battery purchase for a few months. On the one hand I'd kinda like to see how it plays out. On the other, that's my wife's car and I don't want to risk it. Time for a new one. (In the meantime, I kicked off a Recondition cycle to see if that does anything I can see with the tester.)

I'll have to do some more testing with Battery 3.

PS- Beach, to answer your questions: No, I didn't add water to any battery. And the two batteries in question (1 and 3) were charged in the morning of one day and tested the next morning. (And I don't believe either has any significant parasitic drain).