battery fluid low on ONLY one coach battery

[Flame]

Ok, I'm still in maintenance mode after having that electrical problem last weekend. I have owned my rv only about 2 years and have only had to add just a little water to the batteries in that time. Today...I checked them again and only the "left" battery was low. And it was REAL LOW. It took over 1/2 gallon of distilled water to fill and each cell was almost exactly the same amount low!! Why is only one battery seem to be getting charged or used and the other not. They are a matched set purchased at the same time from Walmart I assume because of the Everstart name on them. They are a 27DC group 750 MCA and 109 amp hours @1A. They were in the rv when we bought it and I must admit the date code says 2014. I know it's probably past time to change them but am wondering about the strange loss of fluid "pattern". Side note: They are both still so clean and terminals look like brand new batteries!!

[caconcourse]

It would be interesting to check to see how the two batteries are connected in parallel. For balancing, the main positive cable attaches to one battery, and the main negative return comes from the second battery, so both batteries come into play for a complete circuit. if the main negative return is connected to the battery with the main positive cable, the second battery is like an island, and may not share the load equally.

Also, with a proper charger algorithm, the battery should not be overcharging and boiling fluid. If you still have the original charger (Magnatek and Mark 15), they are not modern 3-stage controllers, and will overcharge if left on continuously (i.e. plugged into shore power for long periods). I replaced my charger (with the Progressive Dynamics 4345) and solar controller (Coleman or Sunforce) and have not lost any battery fluid in almost 5 years. Before the change, I left the Chinook plugged in for a week and experienced some fluid loss.

With your melted fuse problem, there was probably an extraordinary power draw (due to a short or partial short?) which may have stressed your main battery, or led to extra charging and boiling out some fluid.

[Flame]

I do still have the Magnatek. My rv only had 30,000 miles on it when I bought it. Is converting over to progressive dynamic main reason is the overcharging and water loss. I'm sure it saves wear and tear on the batteries. What other advantages do I gain if I convert over?

[caconcourse]

I do still have the Magnatek. My rv only had 30,000 miles on it when I bought it. Is converting over to progressive dynamic main reason is the overcharging and water loss. I'm sure it saves wear and tear on the batteries. What other advantages do I gain if I convert over?

Those are pretty good reasons already. I believe the 3-stage charger should charge faster and is quieter than the old 7345. In your case, you will also pick up a new and better fuse card. The new fuse card also has LED's above each fuse that indicate whether the circuit is active or not.

Here is a link to my old blog references to these upgrades: https://clayrushing.com/2017/01/21/chin ... -upgrades/

The page has links to the parts on Amazon. Note the old solar controller also does a poor job and should be upgraded. The Coleman/Sunforce controller is under a hundred bucks and fits in the same opening as the old one (may need a little trimming), but well worth the cost and effort.

[Flame]

I loved your blog Clay!! To be certain...a new fuse card WILL come with that new unit? Looks like that is going to be my next project. Do you think there is a "plug and play" that is MORE UPDATED since you installed yours or should I just order the one you got?

[caconcourse]

I loved your blog Clay!! To be certain...a new fuse card WILL come with that new unit? Looks like that is going to be my next project. Do you think there is a "plug and play" that is MORE UPDATED since you installed yours or should I just order the one you got?

Thank you, and yes, the PD4645 kit includes the new fuse board.

As for new updates, that is a very good question. From my quick research, I don't see any plug and play solutions that are better. If I were doing this without my experience with the upgrade kit, I would have been tempted to replace the entire power center, but there is no electronic advantage, and it would be a lot more work, certainly not plug and play like the upgrade. The Progressive Dynamics chargers seem to still be a top choice for 4-stage chargers, so there don't seem to be any major advancements to those algorithms. Some will argue that you need programmable voltages and temperature sensors, but truthfully, batteries will charge under almost any conditions. The PD algorithm works well on all types, except Lithium, which have their own built-in charging electronics.

So if I were doing it again, I would stick to my original choice with the PD4645 upgrade kit.

[chin_k]

I just want to say that my interactions with Progressive Dynamics service rep is nothing but excellent, and their technical folks are knowledgeable and helpful. They also stand behind their product, and has no issue of sending you a replacement for any defective unit that is under warranty.

One thing that I would do is to put a spade adapter on the wires, so that it is easier to put under the screws in the new fuse panel. The 8 AWG wire from the fridge is a bit pain to do, but I remember Clay has a suggestion there that will work. PD4645 is not the best charger/converter money can buy, but it is one of the easier replacement for the old parallex one we have in our rig.