Recharge rate

Hi,

Charge acceptance rate at 85% state of charge is 12.5 amps per 100 amp-hours of storage for flooded batteries. The closer the bank gets to 100% the more the charging rate drops.

Attempting to charge faster by increasing voltage simply causes the cells to gas. You do want some bubbles--but one per second is what to aim at.

Solar is definitely a boondocker's friend.

3 hours

Thanks for all your help. As LWDDIS cleverly pointed out it makes solar look pretty good.

wa8yxm wrote:
If you run those batteries down to 50 Percent it's not good for 'em. 75 percent is about the minimum for MARINE/deep cycle beyond that they age very fast.

Now I would not replace them till they need it but when they do consider GC-2 Golf car batteries or GC-12's these are True DEEP CYCLE and do not mind 50% at all that's the design limit though.

To recharge
You have about 200 amp hours (Bit less) so at 40 amps to replace 100 AH would take about 3 hours .. But that will only get you to about 90%. the next 3 hours should top you off.. So I'd go 6 hours Might get there in 5 but I'd say six.

What he said :)

One thing to add. Discharging and partially recharging (not reaching 100% SOC) will shorten your battery life.

Common recommendation is make sure you charge to 100% at least once a week.

When it comes time to replace your current batteries I would recommend looking at something like the Duracell GC2 or Trojan T105. They are "true" deep cycle where the typical group 27/31 "marine deep cycle" is a hybrid starting/deep cycle.

If you run those batteries down to 50 Percent it's not good for 'em. 75 percent is about the minimum for MARINE/deep cycle beyond that they age very fast.

Now I would not replace them till they need it but when they do consider GC-2 Golf car batteries or GC-12's these are True DEEP CYCLE and do not mind 50% at all that's the design limit though.

To recharge
You have about 200 amp hours (Bit less) so at 40 amps to replace 100 AH would take about 3 hours .. But that will only get you to about 90%. the next 3 hours should top you off.. So I'd go 6 hours Might get there in 5 but I'd say six.

If you are manually charging, the max charge rate should not exceed 30% of the battery capacity. A dual purpose Group 27 batteries is rated at 90Ah so charging at the max rate would be 30A. At max charging rate, it should take about 3 hours, probably a bit longer if you have a good multi-stage charger.

If you battery has been discharged to 50% SOC, you have shortened its life.

If your converter is putting 14.4+ volts on the battery you need a solid three hours.
If you have the typical WFCO or parallax at 13.6 volts it will be 12+ hours.

With a good 4 stage converter/charger, 4 hours. WFCO is not a good converter/charger. Magnatek/Parallax is an absolutely s****y converter/charger. My preference (put in 2 RVs) is Progressive Dynamics, although there are others that are as good.

WFCO charger is a POS

Four hours of recommended generator time per day. Not too pleasant if your neighbors are close or even for you. Gee, could there be another way to silently recharge FULLY almost every day? That would be heaven sent.