Misread Trojan Battery Manual
All this time I thought the float voltage for Trojan batts was 13.5V but it's actually 13.2V. I misread the float for VRLA's and wets. Looks like I've been overdoing it by quite a bit. Trojan Batt ...
Forum Discussion
Well if Trojan is recommending a 10 to 20% rate when charging regarding solar, one might assume they are thinking a stationary off grid situation and that solar is the primary if not sole recharging source.
A discharged battery can certainly accept way more than 20%. I've seen my flooded 31 rated at 130 amp hours take 65amps from my alternator which is 50%. My paired 27's could easily suck up 90+ amps when my alternator belt would start squealing.
I did not take SG readings often on my previous pairs of group 27 batteries rated at 230 amp hours fed by 198 watts of solar, I wish I did.
But now I have the same wattage feeding only 130 amp hours of battery and the same general overnight usage. With some tweaking to my solar voltage setpoints, I expect to get a respectable lifespan from my battery in my usage, and a better return on investment than my previous sets of batteries which had larger capacity and were cycled shallower, daily.
Is this due to the voltage setpoints being tweaked in response to SG readings, or due to the Solar coming closer to a 10% rate, or some combination of both? I know not. I have my suspicions and of course I want those to be right.
We all use and recharge our batteries differently. I cycle mine 30 to 50% each and every night and my solar makes up for 90% of the overall supplied recharging current, and I feel that lowering my capacity to approach this 10% Solar recommendation will have me spending less money on replacement batteries in the long run. I have no generator, and rarely plug in. Time will tell.
BUt in the OP's linkm a well respected battery manufacturer is recommending a 10 to 20% via solar, and an oft touted spec on this and other forums is just ~5%. or 1 watt per 1 amp hour of storage.
The 5% figure is certainly easier and more practical to meet. I certainly wanted to believe when Mine could barely reach 5% that it was enough, but I never really got more than 2 years from a pair of batteries cycled daily. Now I've got closer to 10% by having lowered my capacity, and want to believe this will be better in my uses, and cost less in the long run, and it does still have enough capacity to meet my needs.
Everything is a compromise. Data that backs one's choice of compromise gives the warm and fuzzies. Perhaps warm and fuzzies are worthless.
Time will tell.
Regarding float voltages, I consider in my use, float voltage to be 'Storage' voltage. I'll lower it to 13.1 if/when I stop cycling my batteries daily. I set my float voltage as a 'finish' voltage and above my Absorption voltage and only by this method does my SG approach baseline daily.
A discharged battery can certainly accept way more than 20%. I've seen my flooded 31 rated at 130 amp hours take 65amps from my alternator which is 50%. My paired 27's could easily suck up 90+ amps when my alternator belt would start squealing.
I did not take SG readings often on my previous pairs of group 27 batteries rated at 230 amp hours fed by 198 watts of solar, I wish I did.
But now I have the same wattage feeding only 130 amp hours of battery and the same general overnight usage. With some tweaking to my solar voltage setpoints, I expect to get a respectable lifespan from my battery in my usage, and a better return on investment than my previous sets of batteries which had larger capacity and were cycled shallower, daily.
Is this due to the voltage setpoints being tweaked in response to SG readings, or due to the Solar coming closer to a 10% rate, or some combination of both? I know not. I have my suspicions and of course I want those to be right.
We all use and recharge our batteries differently. I cycle mine 30 to 50% each and every night and my solar makes up for 90% of the overall supplied recharging current, and I feel that lowering my capacity to approach this 10% Solar recommendation will have me spending less money on replacement batteries in the long run. I have no generator, and rarely plug in. Time will tell.
BUt in the OP's linkm a well respected battery manufacturer is recommending a 10 to 20% via solar, and an oft touted spec on this and other forums is just ~5%. or 1 watt per 1 amp hour of storage.
The 5% figure is certainly easier and more practical to meet. I certainly wanted to believe when Mine could barely reach 5% that it was enough, but I never really got more than 2 years from a pair of batteries cycled daily. Now I've got closer to 10% by having lowered my capacity, and want to believe this will be better in my uses, and cost less in the long run, and it does still have enough capacity to meet my needs.
Everything is a compromise. Data that backs one's choice of compromise gives the warm and fuzzies. Perhaps warm and fuzzies are worthless.
Time will tell.
Regarding float voltages, I consider in my use, float voltage to be 'Storage' voltage. I'll lower it to 13.1 if/when I stop cycling my batteries daily. I set my float voltage as a 'finish' voltage and above my Absorption voltage and only by this method does my SG approach baseline daily.
