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Nobadays
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# Posted: 27 Apr 2024 10:55 - Edited by: Nobadays
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Made the 10 hour drive Monday up to Colorado. Uneventful, the best kind of drive! Everything looked good up here. Got both the outside cistern and the under cabin tanks filled and both systems pressurized and working... no leaks or frozen pipe issues! solar system in the cabin fired right back up and I hadn't lost any voltage from my battery bank while shut down over the winter, gotta love LiFePo4!

Only problem is with my shop solar. The new last fall Vmax AGM batteries (4×6v @235ah - 24v system) have decided not to run my Starlink overnight anymore. I ran the Starlink off that system for 2 months last fall before we left and the batteries had enough reserve to keep the Starlink on for better than 48 hours. Now they won't even run it for 12 hours overnight.

Will do some troubleshooting today. I was in town yesterday so went to HF and bought a battery load tester. Going to unhook the batteries and test them individually.

Question, is testing deep cycle batteries the same as a regular car battery? I'm pretty sure these 6v batteries don't have a Cold Cranking rating. I guess I don't want the tester to tell me they're bad because they don't release power the same way a car battery does. Anyone have experience testing these purely deep cycle batteries? Thanks!

Aklogcabin
Member
# Posted: 27 Apr 2024 10:58
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Can you check the specific gravity of the battery acid ?

Nobadays
Member
# Posted: 27 Apr 2024 11:35
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Quoting: Aklogcabin
Can you check the specific gravity of the battery acid ?


No they are sealed AGM batteries.

Nobadays
Member
# Posted: 27 Apr 2024 12:38 - Edited by: Nobadays
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Well found a YouTube video by Trojan battery on how to test these deep cycle batteries. Basically the same as any other battery so that good.

One point he made, and this is for Trojan 225ah golf cart batteries, that they have a CCA of ~650A. My guess is any other deep cycle battery at 225ah will be in that ballpark as well.

Hope this helps anyone else with the same question.

BTW I put the Kill A Watt meter on my Starlink to see what it is pulling. On start up it hit 72w but quickly dropped to a fluctuating wattage ~50w as it was making connection. After it was online it dropped to between 28w-40w. When searching on the internet it jumped to ~45w then settled right back down. More often than not it hovers at ~35w

gcrank1
Member
# Posted: 27 Apr 2024 18:16
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I used an old car type load tester on my 4 inherited 12v agm's a few years ago. The one very bad one was obvious, it wouldn't do much even though it read decent voltage. The next was iffy, but I got a few more months out of it before the parallel bank lost beans.
I had numbered all 3 so I knew what looked to be the best to worst under load were; pulled the poorest and had a few more months of better running.
Lead acid likes to be kept fully charged and does not have a huge number of cycles. The worst battery will pull down the rest of the bank. That is the downside of a series bat-bank. With a total parallel bank you can still pull bats out until one 1 is left.
With some luck you may just have 1 bat gone bad. I know 'they say' match the bats but I'd buy a replacement for the 1 worst and give the bank a go.

ICC
Member
# Posted: 27 Apr 2024 20:48 - Edited by: ICC
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Sorry to hear of the battery issues. Happy to hear the drive was uneventful. As you said, those are the best kind. Which is why I have not yet been able to complete a trip to the cabins here.

The final 2 miles is a dirt road that twists and winds up a canyon side wall with a steep 100 to 300-foot drop. Many sections face north and never see sunshine. Snow remains in those places and the winds seem to like making drifts in some of the inside bends. We have had several short snowfalls of a few inches over the past several weeks. Deep enough to say chains would be make for a more secure climb but I don't feel like that, so we wait. I am thinking the first of May will be good.

Nobadays
Member
# Posted: 27 Apr 2024 21:08
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Quoting: ICC
Snow remains in those places


There was still a couple of drifts on our road but others had already busted through them so it was easy for me.

I did have to go help pull a jeep out of a drift about 5 miles up the road. I was going to visit a neighbor and was waved down. They had walked the 5 miles back here, they were 70's.. I was just stoked to pull a jeep out with my Geo Tracker, with the winch but hey, a Tracker pulling a jeep out!

Nobadays
Member
# Posted: 27 Apr 2024 21:10
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Quoting: gcrank1
I used an old car type load tester


That's what I used and unfortunately I could see no appreciable drop on any of the batteries. I was kind of expecting one battery to tank. Now more troubleshooting

gcrank1
Member
# Posted: 27 Apr 2024 22:02
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Remove all connections, clean well and reinstall with the proper torque; some swear by using the antioxidant stuff on connecting surfaces (No-Ox?).

Brettny
Member
# Posted: 28 Apr 2024 06:42 - Edited by: Brettny
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I would also check the connections. Hell even check your system that shuts off the power

Nobadays
Member
# Posted: 28 Apr 2024 09:17
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Thanks guys... of course checked the battery connections yesterday as I had them all disconnected. I'll check the rest and see what I find.

I'm using a Victron 24/1200 inverter which has one of the lowest idle draw in the industry at 8-10watts. They also tout a 90%+ efficiency.

But having functioned fine last fall but not now points to some draw/ something different I'm not seeing.

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