T&T: Installing two inverter/chargers on one battery bank
Christopher Ruby
some input from the electro-intelegencia. The boat currently has two banks
of 2 8-D's each, with parallel switch and a 40-Amp charger and a 50-amp
alternator on each of the two Cats.
I'm considering installing 6 golf carts as a new house bank and adding one
or two 2500 watt inverter/chargers. I'm wondering if I could tie in one set
of 2 8D's (two years old) to the golf cart bats and use this as the house
bank, leaving the other 2 8D's for engine starting for both engines and both
gensets (the starting batteries would still be able to be paralleled with
the much larger house bank).
Is it possible to install 2 inverter/chargers and have them charge the same
bank? This would save a ton of generator charging time. That would be 2
times the 130 amps of charging available from each inverter/charger? I
could use one inverter for the fridge/freezer and the other for all the
remaining 120volt equipment. I'm not clear about the viability of two
charging sources working simultaneously on the same battery bank. I've not
seen this done, so I'm assuming there are some "issues".
Thanks,
Chris Ruby
Bella Luna
currently at Dog River, Alabama
_______________________________________________
http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering
To unsubscribe send email to
trawlers-and-tr...@lists.samurai.com with the word
UNSUBSCRIBE and nothing else in the subject or body of the message.
Trawlers & Trawlering and T&T are trademarks of Water World
Productions. Unauthorized use is prohibited.
Dave Cooper
working simultaneously on the same battery bank. I've not seen this done,
so I'm assuming there are some "issues".>
We have two Trace 4024's charging our house banks in parallel. We just set
one to finish the bulk & charge .1 volt lower than the other. Then the
Absorption time is "0" on one and 3 hours on the other. We also have the
float only on one but we seldom....no never get to a float stage....living
aboard.
These settings seem to work fine for our 16 AGM bank. They will take the max
charge available from the inverters. This is usually limited by available
excess input amperage as the house loads are a nominal 2-3 kw so we have but
7 or 8 kw available for charging at best if the Air Conditioning isn't
running.
We have all AC loads run thru the Inverters. They do a very good job of
automatically managing the genset load. We seldom see the genset loaded less
than 35 amps and limit the load via the inverter to 40 amps max.
As always YMMV
Dave & Nancy
Swan Song
Roughwater 58
Puerto La Cruz
Venezuela
Robin
same brand. If the charging characteristics of the inverters are the same,
both will work together to add their outputs.
I charge using three Statpower 40amp chargers in parallel and they work ok
together. When I parallel two house banks, and add a FREEDOM inverter/charger
with another 130 amp output , they all work well together for nearly all the
bulk (high current) charge....then the Freedom seems to "take charge" for the
absorption (lower current charge).
To minimize genny run time, your charger(s) should equal about 25% of your wet
cell/lead acid battery bank amp hour capacity...example: 4 8D's of 220 amp hrs
each is 4(220) or 880 times 1/4 is 220...So they accept about 220 amps...An
AGM battery, while more expensive, will accept 100% of its amp hour
rating...so charging time is reduced...
Finally, you can have two house banks each with it's load sized proportional
to its bank...and charge them individually...that way you'll never run down
your house bank entirely..this is exactly as efficient as one big combined
system, but takes more planning...
Rob Brueckner
Hatteras YF
Scott Templeton
2,000 watt xantrex inverters with two battery banks say 4 golf cart
batteries on each one or a 2500 watt inverter with 6 golf cart batteries.
What I was hoping to accomplish by the two would be the ability to run a
7-9000 BTU A/C to cool the bedrooms off at night off one inverter and
everything else of the other (fridg,tv and lights)but I am not sure this is
feasable ?
Any opinions? What is involved with using two inverters instead of one?
Mark Richter
2,000 watt xantrex inverters with two battery banks say 4 golf cart
batteries on each one or a 2500 watt inverter with 6 golf cart batteries.
What I was hoping to accomplish by the two would be the ability to run a
7-9000 BTU A/C to cool the bedrooms off at night off one inverter and
everything else of the other (fridg,tv and lights)but I am not sure this is
feasable ?
Any opinions? What is involved with using two inverters instead of one?>>
I'd favor the single inverter mode. Most inverter installations I have
dealt with (many) have not enough battery bank to fully utilize the
inverter's available power. If you separate the loads into two inverter
systems (air cond and other), you will be wasting half your battery capacity
when the air conditioning is not in use.
My old 1000 watt Heart inverter powers my 5200 BTU air conditioner (which
draws about 600 watts) with power to spare. One 2000 or 2500 watt inverter
should easily handle a 10 or 12k air conditioner and still start the refrig
and other small loads just fine. Hook the one inverter to the biggest bank
you can reasonably accommodate, and you'll be happier with the system
performance.
Mark Richter
Mark's Mobile Marine, Ortona, FL
Mike Maurice
> systems (air cond and other), you will be wasting half your battery capacity
> when the air conditioning is not in use.
>
are to provide redundancy, or because of locating issues. Since the
theory is that a bigger bank will last longer, be drawn down less on
average. Which has a big impact on longevity.
Of course one can ignore this issue and scatter batteries all over the
boat, a trend which is quite obvious. But, don't assume that it is the
best trend.
Just ask Arild.
Mike
Arild Jensen
>I will be purchasing an inverter soon and have wondered about using two
> 2,000 watt xantrex inverters with two battery banks say 4 golf cart
> batteries on each one or a 2500 watt inverter with 6 golf cart batteries.
> What I was hoping to accomplish by the two would be the ability to run a
> 7-9000 BTU A/C to cool the bedrooms off at night off one inverter and
> everything else of the other (fridg,tv and lights)but I am not
> sure this is feasable ?
> Any opinions? What is involved with using two inverters instead of one?>>
MARK replied.
> I'd favor the single inverter mode. >>> snip<<< If you separate the loads
into two inverter
> systems (air cond and other), you will be wasting half your battery
capacity
> when the air conditioning is not in use.
REPLY
Who says you have to split the battey bank just because you have two
inverters?
The system will work fine with all batteries combined into one bank but two
seperate inverters for each to handle their own dedicated loads.
I have about 126 system's rigged exactly like that and one of them is using
a Xantrex Prosine pair.
Since both inverter/chargers are identical the charge algorithm wil ensuer
very nearly equal behaviour during chare and transititon from stage to
stage. No Problem!
regards
Arild
Arild Jensen
> MARK replied.
> > I'd favor the single inverter mode.
>>>>>>>>>>>>>>>>> snip <<<<<<<<<<<<<<<<<<<<<<<
> REPLY
> Who says you have to split the battey bank just because you have two
> inverters? The system will work fine with all batteries combined into one
> bank but two seperate inverters for each to handle their own dedicated
loads.
Post Script!!
I forgot to mention a big advantage of having two inverters.
You get twice the charging power compared to a single big inverter/charger.
That in turn means rapid recharge time which is especailly useful when
charging from a genset while anchored out.
For the cruising folks travelling in distant waters having two inverters
means redundancy in case one unit fails.
It means you lose half of your total inverter or charger capacity not 100%.