Odd Battery Behavior

Topic: Odd Battery Behavior (Read 2145 times) previous topic - next topic

Re: Odd Battery Behavior

Reply #50 – December 11, 2018, 01:43:00 pm

I agree with Barry. Years, and many boats and rvs, none without a disconnect. Never understood rvs without. Among first items purchased for FT, two disconnects. Always felt it important to be able to start engine without a jump. Also replaced every two years. Seemed like cheap insurance to not miss the start of a race, (raced sailboats, not rvs).

Re: Odd Battery Behavior

Reply #51 – December 11, 2018, 02:02:44 pm

Quote from: Barry & Cindy – December 11, 2018, 01:39:24 pm

If leaving coach for a while, why not put a high-amp disconnect switch on battery. After putting switches on both banks of our coach, and several months of sitting both banks are still 12.6 volts.

This makes sense for several reasons. Can you provide us with a link to the switches you used?

Re: Odd Battery Behavior

Reply #52 – December 11, 2018, 03:27:04 pm

These are the two I used, with pictures at the end.

Battery Charge while in storage

Re: Odd Battery Behavior

Reply #53 – December 11, 2018, 04:00:34 pm

The disconnect switch is definitely on the spring "to do" list.

I'd like to thank again all of the members here who responded to my neophyte battery and electrical system questions.

Having failed to get one of my new batteries to take a charge, I took them this morning to the Interstate Battery shop and the tech there conducted checks—one battery was defective internally, and this was probably the reason for the entire incident. Interstate replaced the batteries under warranty.

Re: Odd Battery Behavior

Reply #54 – December 11, 2018, 05:25:09 pm

Quote from: RandallBrink – December 11, 2018, 04:00:34 pm

The disconnect switch is definitely on the spring "to do" list.

I'd like to thank again all of the members here who responded to my neophyte battery and electrical system questions.

Having failed to get one of my new batteries to take a charge, I took them this morning to the Interstate Battery shop and the tech there conducted checks—one battery was defective internally, and this was probably the reason for the entire incident. Interstate replaced the batteries under warranty.

We'll get you fixed up in the spring.
Chris

Re: Odd Battery Behavior

Reply #55 – December 12, 2018, 05:09:30 pm

I'm pleased to say that the replacement chassis batteries are installed, engine and genset started and run for about an hour today.

Re: Odd Battery Behavior

Reply #56 – December 12, 2018, 08:50:38 pm

Are you plugged in? :+)

Re: Odd Battery Behavior

Reply #57 – December 13, 2018, 12:07:40 am

Oh yes, plugged into 15a socket with no other electrical on except charging converter.

Re: Odd Battery Behavior

Reply #58 – December 13, 2018, 03:42:43 pm

Randall, don't forget your house batteries. I Plug the coach's power cable into 110v while in storage. This keeps the house batteries charged. I have a battery minder plugged into an 110v outlet Under the bed and that is hard wired to my engine batteries and keeps those charged.

Hope this helps.

Re: Odd Battery Behavior

Reply #59 – December 14, 2018, 12:07:32 am

Thanks Jeff—similarly, I have the coach plugged into 110vac for the house charger, and the Deltran battery tender hooked up to the engine batteries.

Re: Odd Battery Behavior

Reply #60 – December 14, 2018, 12:59:34 am

Sure easier to replace the isolator with the now industry wide standard combiner.

If either battery is receiving a charge the combiner connects them.

Just saying.

Can be manually turned off if you had a bank way down on charge to allow it to catch up.

Re: Odd Battery Behavior

Reply #61 – December 14, 2018, 09:26:13 am

Just be aware that the combiner is great for battery banks of similar chemistry and similar voltages but a standard combiner would not work for tying a lithium bank (13.6v) to a wet flooded acid bank (12.6v), for instance. It would see the voltage difference as a reason to constantly tie the 2 banks together. I was glad to still have the OEM style isolator that made the lithium conversion easy.

Re: Odd Battery Behavior

Reply #62 – December 14, 2018, 10:54:24 am

Keeping both my battery banks receiving a charge automatically during long term storage seems to have worked well with the combiner.

Heavily researched li-ion 6 years ago but the temp restrictions without damage were a problem in my mind.

Would not a li-ion battery normally have a built in BMS that would prevent overcharging? My small solar puts out 13.6 volts at the batteries.

Optima red tops and my mk gels seem to be ok receiving that voltage always.

Same as my adjusted alternator outputs.

Only temp controlled charging I have is the inverter/charger.

The test would seem to be if the gen was running or I am plugged into a power pedestal does the charger add more amp hours showing a plus on the power pro meter?

If not then the setup would seem to be optimal at 13.6 volts from,both the solar and alternator would it not?

I hope my continuous charging from the solar/combiner will keep the batteries up and not cycle them very much to increase their life and capacity.

I know for sure running any battery down regularly shortens their life and reduces their capacity.

A resting fully charged battery is 12.85 volts as far as I know. At 12.6 the battery is 30%? Discharged.

So I keep,my batteries at float from the solar and combine them to lower the isolator losses.

The AGM engine and gel house banks both seem to be able to use the 13.6 volt storage volts ok.

My guru buddy says I should be fine. ,

Time will tell.

Re: Odd Battery Behavior

Reply #63 – December 14, 2018, 12:05:21 pm

This whole topic has been discussed a million times on here. All kinds of interesting data and theories.
Not going to argue any of them, just going to throw out my own humble opinion from what I have seen in the streets, hands on as a RV tech for over 50 years, and a RVer myself for almost as long. New and old equipment, every kind of charging system.

I would never leave a coach plugged in 24/7 with any kind of inverter/charger long term, no mater how technically advanced it is.
Charge the batteries to full, physically disconnect them. Physically check them periodically. If leaving your coach plugged in 24/7 works for you, by all means do it.

In our coral of collector cars, race cars, Harley's,race car trailer, lawn mowers and pit bikes etc. we have a total of 25 batteries. Every year I charge them fully, disconnect them physically, and leave them in place for 3 months as we go south. The only exception to this is our 15' Dart. I leave a tender on it, because of all the memories, and I don't want to unhook the batteries. Never have any issues with dead batteries, they all start the vehicles right up in the spring.

Second, I would never tie two different battery banks together via a coach inverter/charger for any period of time over 24 hours.
The engine batteries are going to get overcharged,period by this method. I have heard all the arguments. Regardless you still have a in-balanced battery bank. Therefore the engine batteries are going to be overcharged,because as they are satisfied, while the house batteries are not.

In simple words: Engine batteries " I am done". House batteries " Give me more".

Chris

Re: Odd Battery Behavior

Reply #64 – December 14, 2018, 01:08:26 pm

Would not a li-ion battery normally have a built in BMS that would prevent overcharging? My small solar puts out 13.6 volts at the batteries.
Yes, the BMS will prevent overcharging. That's not the point. My point was simply that the combiner will see the voltage difference between the 2 banks as a trigger to connect them....all the time. That will drain the higher voltage bank to the lower voltage bank. That was my understanding anyway, after consulting Battle Born about it. Might have misunderstood though.

A resting fully charged battery is 12.85 volts as far as I know. At 12.6 the battery is 30%? Discharged.
Close enough. It was just an example to make the point. The lithiums are probably higher voltage than I quoted as well.

I'm not knocking combiners or anything else, just pointing out that they aren't the standard solution for every situation.

Re: Odd Battery Behavior

Reply #65 – December 14, 2018, 01:14:53 pm

We full time, plugged into the pier. Sure do love this unit! Has a in-coach option, I know what's going on ALL THE TIME with both banks!

Re: Odd Battery Behavior

Reply #66 – December 14, 2018, 02:14:26 pm

I questioned my guru buddy extensively about the red top/gel combo. While no non identical system is perfect in actual long term use his results have been excellent.

Not sure when Foretravel changed their production but every newer Foretravel built coach has a similar system to mine.

Redtops/gels/combiner/solar?

340 amp alternator into 6 mk gels and 250/300? amp battery charging from dual inverter/chargers.

Works for the nice million dollar folks should work for me.

Mine auto disconnects at night with no solar input. No shore power.

Small solar (14 amps) and small wires to the back of the refer and a old tech controller seem to be fine as the one volt drop from the small wiring seemed to work out fine at 13.6 at the batteries.

Afraid to change it.

May install a separate newer tech solar as i have some of the parts already,

Every new coach made in the biz has a auto combiner as far as I understand.

Re: Odd Battery Behavior

Reply #67 – December 14, 2018, 02:29:18 pm

Best simple explanation I have found:

Can I Connect Dissimilar Batteries in Parallel?

Re: Odd Battery Behavior

Reply #68 – December 14, 2018, 09:29:11 pm

I can only verify that red tops and mk gels work together as that's what Foretravel uses on its new coaches.

With a combiner. That's why I refit the original oem system to our coach. Anything else you are on your own and I am not interested in testing variations like I did long ago.

My 97 did not have a BTS as it's Freedom 25 was pre 100k serial number and it's was not full sine wave.

And the already mentioned combiner.

Exactly like Foretravel currently builds.

The mk engineer mentioned 10-12 years life from Foretravel owners.

That's is with isolators as combiners we're not available then

Remember red tops and mk gels. Lowest cost per cycle. Can take a combiner according to Foretravels build

Re: Odd Battery Behavior

Reply #69 – December 15, 2018, 02:30:07 pm

Quote from: Dakota Slim – December 08, 2018, 01:04:30 pm

Your coach is stored inside with no power available?
Any number of things could be draining your batteries. You need to charge them and either keep your coach plugged in with some kind of charging system or disconnect the batteries until you are ready to go.
Obviously, if any of them won't hold a charge you need to replace them. If they are new I presume they have a warranty. It's always better to do that where you bought them than to wait until you are 1,000 miles away.

I have had a similar problem with my batteries in the past , I have a wind generator that puts out about 4.5amps per HR when really windy, but I've noticed that even if I switch the isolator off the house batteries if left for a few days with no wind , then their is a definite voltage drop , their is the smallest of spark on the earth terminal of battery when I touch it together I've never managed to find where this power drain is , so now when I leave it and am not using vehicle I just disconnect earth battery cable completely and keep the wind generator connected , no more power drain and plenty of charge in batteries after three weeks of being away from it , I still have to work out where the power drain is , I've looked everywhere over the past 7 years without success everything is off no lights on ,I've just learnt to compensate the problem by disconnecting batteries when not in use

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