Second guessing myself....

[1953 Flying]

I just changed out the old batteries of new ones. My father inlaw installed the inteli charger and inverter like this.


INVERTER WIRES
2 negative wires coming off the inverter going to 1 battery ( see pic 1 )
1 each of the positive wires going to each battery (see pic 2 )

CHARGER
2 negative wires going to battery 2 oppisite of the inverter
1 each positive wires going to each battery


Attached Thumbnails



and then I found this.


Two Batteries in Parallel, One Charger


Figure 9: Two Batteries in Parallel, One Charger
Batteries connected in series strings can also be recharged by a single charger having the same nominal charging voltage output as the nominal battery pack voltage. In Figure 8, a single 24-volt charger is connected to a 24-volt battery pack.

In Figure 9 we see a pair of 12-volt batteries connected in parallel. This 12-volt battery pack is connected to a single 12-volt charger. Note the blue wire designated W1. The purpose of this wire is to balance the voltage drop evenly across both batteries and each wire during charging. This is not critical for lower current chargers, but when you start to get into the 10 amp and above range, the voltage differential can be significant. The blue wire W1 must be connected to the opposite end of the battery pack as the black wire at the top of the battery pack.

When batteries are connected in parallel, only use one charger. Do not connect a charger to each battery, unless you break the electrical connection between the batteries. The reason is that the chargers will very likely complete one or more their charging subroutines (charge modes or stages) at different times. That means that each charger would be trying to bring the battery pack to a different voltage level. Depending on how the chargers are configured to prevent a reverse polarity connection, the charger with the lower voltage output could possibly draw current from the charger with the higher voltage output, or even from the battery pack that it is trying to charge. If the chargers' reverse polarity protection mechanism includes a solid state, unidirectional, voltage controlled, current switch (like a diode), then this is not a big problem.


So if I read this correctly. I should be connecting both positive wires from the charger to one battery, and the two negitive wires from the charger to the opposite battery. And the same for the inverter? Please help I'm so confused.

[1953 Flying]

Lots looking but know replies. So, I went ahead and rewired them up the way my father in law had them.

I took one + wire from the charger and hooked it up to one battery and the second + wire and hooked it up to the other battery.

The 2 negitive wires from the charger went to battery #1.

Then I ran 4 guage wire to both + and negative termanels to make them parallel.

The inverter + wire, I put them one each on each battery. The 2 negative wires went to battery #2.

The reason I was second guessing myself was, It seemed the batteries should of lasted longer. About 5yrs or so doesn't seem long enough. We never put alot of draw on them, the smart charger always keeps them topped off and I always kepted them maintained. And I have never drained the batteries all the way down. If they should connected a different way please let me know.

Thanks for the help,
Robert

[Excella CM]

Once the batteries are in parallel, the inverter and charger can be connected to either or both batteries, it makes no electrical difference providing that the paralleling wires are big enough.

[Wabbiteer]

There are better tutorials on the web, this is the first I could find doing google search, Why they do the connections symmetrically opposed.

[Mexray]

1. I would get some SS nuts to replace those 'wing nuts' on the batteries - with that many wires/cables on each terminal, you want the connection clean and TIGHT - wing nuts are difficult to get a really tight connection...

2. Since you have two NEG and two POS cables from the inverter, why not connect one of each to each battery? By running both NEG cables to one battery you have then effectively doubled the 'size' of the cable - however using the 'single' POS cable on the other battery terminal has limited the current capability to the single cable size - the doubling of the NEG cables does no good...So just hook one cable to both POS and NEG terminals on EACH battery, and be done with it...

3. You have effectively hooked your two batteries in PARALLEL with the inverter cables - the addition of the two new POS to POS and NEG to NEG cables is probably a good idea so both batteries are charged/discharged evenly...

4. I'd like to see some fusses in your inverter to battery cables, as additional protection in the event of a melt-down of the inverter...

5. Last suggestion...make sure your batteries are contained in some sort of box or strapping so they don't move around when you're on the road - too much movement will cause the ends of the copper cables to work harden and could come loose causing sparks, fire, or worse!

Also, 5 years on your batteries isn't all that bad for a system that sits around without use much of the time...4-6 years for most normal deep cycle's you find in the market place today is 'par' for the course...

[masseyfarm]

This is the correct way to connect batteries in parallel. If one post has a poor connection, it will be readily apparent.
If you connect both charger/invertor cables to the one battery, and the post on the second battery gives poor contact, the result is only one battery is doing the work.
Dave

[1953 Flying]

I think Mexray's idea looks to be the most efficient way. Thank you.

We did build a small rail that goes around the batteries holding them from sliding around and a strap that goes over the top holding them down. I feel every thing is safe and secure.

Now regarding the fuse between the inverter and batteries. What exactly does this in-tell of?

[Mexray]

I used something like these inline fuses from West Marine... http://www.westmarine.com/webapp/wcs...classNum=11287 this type of fuse (i used 50 amp)also comes with it's own mounting block, but I mounted them inline without the block near the inverter in our old truck camper...I wouldn't mount them on the battery posts, in the event of a 'flashed' fuse, and possible sparks could ignite any hydrogen gas near the batteries...

You might check out the 'Maxi' type two-prong automotive fuses at a local auto parts outlet - you can get them in 50 amp ratings, and possible a matching fuse block as well...just a suggestion...

One other note: looking at your pic that shows the inverter and converter...it looks like you're using heavy copper stranded AC type wires as your load cables (wrapped in red tape)...this type of wire isn't as flexible as thinner stranded DC type wiring cables, but will work if installed so it won't be 'moving around' on the road -

I would suggest that you solder each of the inverter wire connectors (to the wire) where you have 'crimped' the sleeves - those connections with the AC type wire may work loose, or not give you the best of a connection by crimping only...soldering will insure a good DC connection over the years...

If you have other connectors with this same wire, soldering should be considered - especially the connectors at the batteries - soldering may help reduce any corrosion problems on down the road...

Soldering on that heavy wire (cable) will require a heavy iron or HD gun - I've even used a propane torch with a small tip to get good flow on those kinds of connections...

Happy Trails...

[Mexray]

I deal with Quick Cable Corp, and they have lots of good battery wiring stuff to cure those electrical ills...


I've listed a few in-line fuses and a circuit breaker to illustrate some options - their catalog is full of 'goodies'...

1. Quick Cable: ANL Fuse Holder

2. Quick Cable: ANL Type Power Fuses

3. Quick Cable: Manual Reset

4. Quick Cable: ANL Fuse Holder, Fuse Block Kit

[Bill M.]

I think 5 years is a good life for flooded cell deep cycle batteries.

[1953 Flying]

Originally Posted by Bill M.

I think 5 years is a good life for flooded cell deep cycle batteries.

This seems to be the general consensus for the life span of the batteries.