That was the general gist... The Charge controller will pass dc through from the "charger" or in this case the power supply to the load under normal operations, but be aware of the maximum current flow needed for the repeater as well as the batteries for charging...... a large stack of batteries has different charge rates and floats per battery... paralleling them makes for messy charging... Everything assumes each battery will charge/discharge at the same rate.. if the batts are matched this is true.. but 12v batts tend to be made up of several cells and those individual cells age differently in most batteries... assumptions will boil a cell and avalanche from there....One larger battery is better than several smaller batteries... or put a separate charger on smaller groups... A big bank of say 8 90a/hr batts is going to take a lot of charge and that level could hurt the weakest cell in the lot under full bulk charge.. the deadest batt will take current first.... but 800 a/hr worth of batts will take a long time to recover if a discharge occurs...at 30 amps... sustained like 24hrs... if you double the charge current with a bigger charger.. you could be charging one battery at 60 amps.. and you should be real careful about that...
Most serious battery stacks are series arrangements.. and higher voltage but flat current through the system... then run a UPS to get to 110v.... Many of Trace Engineering (Xantrex) and other makers of UPS type Inverters use 4 12v batts in series for 48v... the invert to 110v.. Series and higher voltage uses smaller wire gauges to accomplish backup... I would recommend talking to vendors before paralleling 10 batteries on a 12v charge controller...I would think some additional engineering would be suggested... Paralleling 200-300 amp batts is one thing.. paralleling 80-90 amp gel cells is another matter... especially 10 of them... Surplus is not necessarily a bargain.... Doug KD8B At 10:48 AM 2/16/2009, you wrote: >AJ wrote: > ><snip> > > I know in a recent conversation here on RB, one of the users had a > > Solar Charge Controller inline between his 12 volt power supply (in > > our case a GE Mastr II 30 amp supply) and the actual repeater equipment. > > >That was me askin' the questions, and Doug doin' all the answerin'. :-) >Basically, what he (and others) advised was to make sure of the maximum >charge rate on your batteries, and to not exceed that charge rate. Doing >so causes heat buildup in the batteries and will over time boil them >dry, causing failure. > >Google Xantrax (I think that is how it is spelled) solar charger and you >should find what you want. Your application is exactly the same as ours, >except we are probably only looking at 8 hours. After that, we can pull >one of our trucks up to the site and use jumper cables if it is still >out... > >Anything to add Doug? Mike KA4MKG
