12v wet Lead acid question-2023 micro Minnie 1720fb

[1woodward1]

If I add a 2nd battery in parallel do I need to do anything to my solar charger? Also, is it ok to add a new battery to the older battery? The old battery is only a few months old but has been used. I have 190 watt solar panel.

[1woodward1]

Wrong forum. How do I delete?

[Ray,IN]

Batteries of different ages should not be mixed. The weaker one will drag the new battery down to its level quickly.
As to the solar charger, you need not change anything, the result will be a slower charge for both batteries. You can increase the charge rate if your setup has the capacity; for LA batteries the charge rate should be 10% of the total amp/hrs for the best longevity..


This is the correct forum; however,
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[creativepart]

While it is true that it’s best to replace multiple batteries at the same time, it’s not absolute. Besides, who says any two batteries on the shelf are “matched” when we buy them? So, if your older battery is less than a year old and hasn’t been abused it’s not the end of the world to add a new battery to accompany it.

As Ray, IN says if the old battery is compromised it will bring the new battery down to its level, but if that first battery isn’t too old or too abused then sometimes we have to go with what we’ve got.

The sooner the better for an additional battery on any RV.

[Morich]

Agree with the idea of not replacing the existing battery if it has not been abused, etc. just a judgement thing that they do not recommend tying new to old.
As far as charging, the two will be slower to come back to full voltage than one single, but that is also kind of how we speak of them charging.
If we think of them as one single bucket or two buckets. we can say the two buckets take longer to fill but we know the amount of water we are putting in is the same.
Takes long to fill two buckets but we are putting in the same amount if we talk about how much charge we get in an hour, etc.
You put it in at the same rate so we can say it charges at the same speed but if we talk about going from 90% full to all the way full it takes longer on two batteries and than one!

[Marine359]

2023 would seem to be a new RV. Dealers do not take care of batteries when they sell an RV. Trailer comes to dealer maybe with no battery, and dealer installs a battery which may or may not be in good condition. If you do a hydronic battery test on the one you have, and it checks out ok, it’s perfectly ok to add a second marine deep cycle of equal CCA. If it does poorly on hydronic test, don’t pair it with a new battery. Nothing needs to be done with your solar setup. For $300 you can just drop in a single new 100ah heated LiFePo4. If you do, you may need to reprogram you WFCO converter/charger for lithium profile. I think all new WBGO towables have that feature.

[MadMaxWinny]

If batteries are well maintained and not subject to abuses, they can last a very long time. As already mentioned, it's not necessarily a bad thing to mix batteries. Once you are set up and after fully charging both old and new, one good test is to disconnect the batteries (from all loads AND each other) and let them rest overnight. Check each battery voltage with a multimeter. If there is a difference of more than 0.2V between the two, I'd be looking at replacing the older one.

As for multiple charge sources, 12V DC doesn't feedback, so there's no issue with many charge sources, BUT remember they must all be marching to the beat of the same drummer. An older failing charger (or one without good voltage control) can still cause issues.

[The Raptor]

Cave-Man Lead Acid Batteries (LAB) of different ages are fine to mix, the Modern way to Re-condition them is use a De-sulphuriser, as the reason nearly all LAB fail earlier is the Sulphur Crystals form Over the outer Lead surface !

NB: The main caused of LAB failure is if/when left Flat for long period of time, Sulphur crystals cover the Lead surface in the battery by being left flattened.

Desulfurisation units come in cheap Clip-on AU$20~AU$50 unit or some good Quality Battery charges have a Desulfur function.
[Australian links removed for clarity to our mainly US membership]

VERY DANGEROUS Old school way for ill educated, is to connect an Inverter Welder set on the Lowest setting for Short periods at a time will re-melt the Sulphur back into the Acid, if the Lead has Not been eaten away.

However, a Sealed LAB battery may EXPLODE if left connected for more than a minute or so at a time, and should ONLY be done Outside, and the Welder switched on & off at a distance at the power point.

We have actually Mixed LAB & LiFePO4 batteries for years, as there is little difference in the Charge voltage.

However, be aware Lithium-ion is the more susceptible to Thermal runaway (Fire), than the Safer Lithium-iron Phosphate (LiFrPO4) chemical battery Technology.

[MadMaxWinny]

Equalizing batteries can indeed add considerable life, but it's not for the weak of heart. A "controlled" and intentional overcharge drives the sulfate plating back into solution.

I've never used one of the inexpensive clip-on options, only the algorithms included with many high-end chargers. Points to remember:

- Disconnect all cables from the batteries.
- Make sure the area is well ventilated (MASSIVE, potentially explosive fumes will be involved).
- Have at least a gallon of distilled water on hand, along with a small funnel (do not use tap water). You will be adding water to the cells nearly continuously.
- Wipe up and neutralize all of the acid that is produced on the top of the batteries.
- NEVER try to equalize a sealed battery (if you do, call the fire department in advance).

And a big smile for the "hold my beer" Welder solution. No thanks!

[The Raptor]

Originally Posted by MadMaxWinny

Points to remember:

- Disconnect all cables from the batteries.
- Make sure the area is well ventilated (MASSIVE, potentially explosive fumes will be involved).
- Have at least a gallon of distilled water on hand, along with a small funnel (do not use tap water). You will be adding water to the cells nearly continuously.
- Wipe up and neutralize all of the acid that is produced on the top of the batteries.
- NEVER try to equalize a sealed battery (if you do, call the fire department in advance).

And a big smile for the "hold my beer" Welder solution. No thanks!

Good input !
Yes, only a Fool would attempt to use the Inverter Welder method indoors, as the Hydrogen Gas produced may Explode if a Spark ignites it.

I have used several Clip on units, some flatten the Batteries, I like the ones with a Digital reading & Pulse Flashing Led, but they can take several weeks to do any Good.

[Ray,IN]

Originally Posted by MadMaxWinny

Equalizing batteries can indeed add considerable life, but it's not for the weak of heart. A "controlled" and intentional overcharge drives the sulfate plating back into solution.

I've never used one of the inexpensive clip-on options, only the algorithms included with many high-end chargers. Points to remember:

- Disconnect all cables from the batteries.
- Make sure the area is well ventilated (MASSIVE, potentially explosive fumes will be involved).
- Have at least a gallon of distilled water on hand, along with a small funnel (do not use tap water). You will be adding water to the cells nearly continuously.
- Wipe up and neutralize all of the acid that is produced on the top of the batteries.
- NEVER try to equalize a sealed battery (if you do, call the fire department in advance).

And a big smile for the "hold my beer" Welder solution. No thanks!

One should not fill cells with water then charge a battery, it will surely heat up, expand the liquid to overflowing.
Instead the cell plates should be covered with liquid, chargee to over 90%, then filled to tthe split-ring with water. This is especially true for an equalize charge..