I have a pair of interstate Costco 6v that are about 3 years old. We don't boondocks anymore and the trailer is at the ranch and hooked up constantly. PD9855 (?) does the charging. I did a SOC and all 6 cells are 1.275 or slightly higher. I checked the voltage on the positive (connection) battery and it is about a half a volt higher than the negative (connection) battery.When I put the Meanwell on the positive battery bubbles like crazy and the negative battery barely bubbles.I reversed the battery and the negative battery still does not bubble much. I cleaned all the connections and the interconnect cable reads 0 ohms.I'm pretty sure it means new batteries.

Hooked up constantly bothers me. I keep my batteries on a light duty solar system with a controller. Three years isn’t exceptional.

I always had different voltages with 6s in series. If the total was 12.6v, that might be 6.2 plus 6.4. You get more like 6.0 plus 6.6?I would give the pair a deep cycle to say 50% SOC and then a recharge and see what the SGs are after that. Maybe now a difference will appear, or maybe the voltages will even up some. Hard to tell now with all the SGs looking good if anything is wrong. They might just need a bit of exercise. Battery specs recommend doing that every so often if they are on a float for a long time.

Are you still using the trailer, other than where it's parked now? IF not, or if never without hookups available, you may want to simplify to a single 12 VOLT rv/marine battery just to simplify.

BFL13 wrote:I always had different voltages with 6s in series. If the total was 12.6v, that might be 6.2 plus 6.4. You get more like 6.0 plus 6.6?I would give the pair a deep cycle to say 50% SOC and then a recharge and see what the SGs are after that. Maybe now a difference will appear, or maybe the voltages will even up some. Hard to tell now with all the SGs looking good if anything is wrong. They might just need a bit of exercise. Battery specs recommend doing that every so often if they are on a float for a long time.I'll give the deep discharge a try. I am concerned with the significant difference in bubbling between the 2 when on desulfation. They have been on "float" for a couple of months. Not much camping in the Mojave in summer.

I think I'm looking at new batteries. | Good Sam Community

joshuajim
Explorer II
Oct 01, 2019
Final report - I put the batteries back in and turned off the disconnect. After 3 days they are still at 12.7. All is well.
joshuajim
Explorer II
Sep 30, 2019
MEXICOWANDERER wrote:
No do them separately and use a hydrometer, to verify the weak sister cells. Ideally, each 2-volt cell would be available. That ended when the over-the-top tartop batteries disappeared.

The equalization Must be current controlled. 5 amps per 100 amps amp hour capacity or 5%.

MEX, you have mentioned using the 100w bulb to control amperage many times, but how are you actually measuring the amperage.
MEXICOWANDERER
Explorer
Sep 30, 2019
No do them separately and use a hydrometer, to verify the weak sister cells. Ideally, each 2-volt cell would be available. That ended when the over-the-top tartop batteries disappeared.

The equalization Must be current controlled. 5 amps per 100 amps amp hour capacity or 5%.
wopachop
Explorer
Sep 29, 2019
My friend has a trailer with (2) 6v costco batteries. They are around 4 years old. Never seen an equalization charge.

Ive asked many times to mess around with them and get shut down. Lets say one day im allowed to do the MEX 16v equalization charge like you taught me in a different thread.

If i do charge them together at 16v and notice one battery bubbling stronger than the other, is it best to charge them individually? Since i have the ability to do so?
MEXICOWANDERER
Explorer
Sep 28, 2019
MEXICOWANDERER wrote:
Jim now that you resolved your own issues (Involved using intelligence I may add):)

This is the missing link in your diagnostics...

It's fast, inexpensive and impossible to fool. It may show a bad battery and will declare it needs further investigation is needed with a hydrometer. Equalize, or end up as a bad battery depending on the hydrometer results.

For those of you who deem the sixty bucks, the purchase price will screw up your weekend beer budget...keep up the poor guesswork you'll need it for gasoline or replacing good batteries with good batteries.

I sneaked in an unrelated quip. I hope you focused on it. Then I posted this latest remark praying some of you can follow the dots
MEXICOWANDERER
Explorer
Sep 28, 2019
incomplete
MEXICOWANDERER
Explorer
Sep 28, 2019
Maybe this sense different become clear more...

Cheap price battery is harder to care for. Die soonest. Use more electricity to maintain. Problem with OP resolved. Maybe good time to change gears?
whiteeye42
Explorer
Sep 28, 2019
MEXICOWANDERER wrote:
Wanna Shock?

Connect a three-cell battery to a three-cell Rolls battery of the lightest weight. Then perform a charge efficiency factor verification test at the beginning and after 50 full 50% discharge cycling series. SURRRRR-PRIZE! The Rolls charges faster and easier. Connect parallel 3 or 4 budget 3 cells in parallel then to the single Rolls. Even more shocking. And the ROLLS is far more forgiving.

Cheap batteries are unforgiving -- they will screw you into the ground. There is MORE difference between a T-105 and a Rolls battery than between a Trojan and a cheapo warehouse three cell battery.

Never try it but offer tons of advice is a loser. For totally different reasons its like comparing a Lifeline to a Chinese AGM. The charge efficiency factor difference comes at a shock to most people.

What is this it does not make sense ?????
MEXICOWANDERER
Explorer
Sep 28, 2019
Wanna Shock?

Connect a three-cell battery to a three-cell Rolls battery of the lightest weight. Then perform a charge efficiency factor verification test at the beginning and after 50 full 50% discharge cycling series. SURRRRR-PRIZE! The Rolls charges faster and easier. Connect parallel 3 or 4 budget 3 cells in parallel then to the single Rolls. Even more shocking. And the ROLLS is far more forgiving.

Cheap batteries are unforgiving -- they will screw you into the ground. There is MORE difference between a T-105 and a Rolls battery than between a Trojan and a cheapo warehouse three cell battery.

Never try it but offer tons of advice is a loser. For totally different reasons its like comparing a Lifeline to a Chinese AGM. The charge efficiency factor difference comes at a shock to most people.
time2roll
Nomad
Sep 27, 2019
wopachop wrote:
I'm not far from you if you ever want to equalize the 6v's individuality. But reading this morn is sounds like everything is ok.
I think the primary concern of the OP was during an equalization (Meanwell) the amount of gassing was somewhat different in the two batteries.

I see no issues.

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