New battery bank... 1000 a/hr bank or 1300 a/hr bank?

alyaz

The batteries I am considering have a 1000 a/hr or 1300 a/hr size.  Our current bank that is about 12 years old is 1065 a/hrs @ 20 hr rate.  (12 - 2 volt batteries for a 24 volt bank).  Am I missing anything here in my thinking about pros and cons of the two sizes?  I am leaning towards the 1000 a/hr batteries at this point.

1300 a/hr batteries - pros:  they should last longer than the 1000 a/hr batteries because over time they would cycle less; during sunny summer months I can store more solar energy as I am usually floating by about noon.

cons: will require more gen run time in winter and shoulder seasons; cost more than the 1000 a/hr batteries.

Thanks.

mcgivor

Depending on how much fuel the generator uses, plus wear tear, and service costs, it may be cheaper to expand PV, if the controllers are not maxed out. This would be for the larger Ah capacity, but one thing missing is how deeply the batteries are discharged, if historically the depth of discharge is shallow the added capacity may be wasted, or not utilized and if you're not using it you're loosing it. Batteries will degrade over time eventually dying even without loads, so sometimes less is more. If you got 12 years out of the current  bank, perhaps the ballance is good, so staying with the same capacity could be the best choice.

alyaz

Thanks.  I have been running the batteries down to 24.4v, at the most.   

westbranch

Al, what are your daily Ah used? Looks like you would be getting about 100 Amps max, for charging, out of your system ... Are you anticipating an  uptick in consumption?

BB.

Any thoughts about going to 48 vdc battery bank?

Fewer mppt solar chargers (typically around 80 to 90 amps per controller maximum... A 1,000 ah battery bank would like around 100 to 130 amps of charging current... 500 ah @ 48 volts, 1/2, the charging current.

Bill

alyaz

I would think we are at about 5.5 kwh a day now.  We have adopted yet another dog, which we feed raw, so we have moved to two electric fridges and two small chest freezers.  Greenhouse watering etc....

I like the sound of a 48v bank but pretty sure I would need a different inverter... off the top of my head I believe I now have the Magnum PAE-4024.  

Raj174

The Magnum Energy MS4448PAE 4400 Watt Sine Wave inverter 120/240 Volt should be pretty much a drop in replacement. They sell for $1776.00 here at NAWS.

Rick

Photowhit

You already have a working system and even an extra charge controller, as we have discussed before. I'd stick with the working system. I do hope to change when I replace my battery bank. But I'm running nearly half the battery bank you are, a remnant of my previous cabin system and haven't yet bought the proper inverter for my system.

alyaz

I had considered buying my new batteries from the sponsor, but living in Canada makes the process much more involved.  I could have them shipped to an address in Sumas, WA, but concerned with what may happen at the border when bringing them back.  Seems to be a lot of added tariff talk right now etc.  It is difficult to get a straight answer from the border people...  Oh well.  

Estragon

I bought most of my system from our hosts (~4 years ago), had it delivered to the ND border, and had no issues crossing the border. Had to pay GST, but that was about it. The batteries I got locally though as shipping costs were prohibitive relative to price difference.

alyaz

Just thinking out loud here... so my last dilemna is do I go for the new bank of tubulars ($6248 shipping included) or the Rolls/Surrette 4KS21 ($7500 shipping included).  The Rolls/Surrettes are about 100 a/hr more capacity, and arguably a more tried and true company/technology... something I haven’t mentioned is that our home is up for sale (but seriously because of the remote location it could take years to sell).  So on one hand I don’t want to spend unneeded money, I still seem to like buying and getting quality / value.  :-)

mcgivor

Buy the new batteries and the home will sell, not because the new owner appreciates the fact, it's just how it works, if I want rain I'll pump water for irrigation, if want sun, run the generator, it's a backwards principal. .... or so it seems..

Estragon

Rolls are based in Nova Scotia, and I believe warehoused in Vancouver. You may want to check around locally for pricing, or maybe NAWS does a drop ship out of Vancouver?

BB.

+/- 10% in capacity between batteries is something that you will probably never notice...

Check the charging voltage of the battery vs your DC input voltage range for your AC inverter/AC to DC battery charger(s)... Rolls (and many "industrial" type batteries have pretty high charging/EQ voltage requirement vs what a "typical" consumer AC inverter can accept...

Typical AC inverter (even those with good quality) may accept 10.5 to 15 volts (24: 21-30 volts, 48: 42-60 volts)... While the industrial batteries take 16/32/62+ volts to charge. Add that cold batteries take higher voltage to charge (-5 mV per cell per degree C over room temperature, warm batteries--lower voltage; cold batteries--higher voltage). For those of us not in the great white north, the issue of high battery bus voltage faulting the AC inverter DC input voltage alarm, not a common issue. For those of you in the North, can be a real pain in the neck (cannot run AC inverter while charging/EQing a "cold" battery bank using "industrial" batteries--Have to bypass inverter to run AC loads while charging from genset/EQing).

-Bill