House batteries not up to ah rating
Bought 2 new Interstate SRM-24 group 24 RV/Marine batteries a few months ago. I have used the MH 4 times on trips lasting from 3-6 days. Never going below 40 amps before recharging. The rating is 85...
Forum Discussion
It will be necessary to desulphate the batteries individually this time round. The second one in the chain will need more attention and most probably is acting as a parasite on the first one.
The 15 minutes of 14.4 volts every 20 hours from the PD is more about stirring electrolyte than desulphating the plates. It is better than nothing but...it just can't do the deed.
BFL13 has a great thread on recovering sulphated batteries. A good temperature compensated hydrometer should be used.
Be sure to NOT expose the control boards in your RV to anything over 15.4 volts.
The absolute minimum amperage for equalization is c/20 (or 5 amps per 100 amp-hours).
You may need to "direct connect" the panels to the battery (i.e. do not use a charge controller). A sulphated 12 volt jar will laugh at 15 volts of equalization charge. 16 volts may be needed.
The 15 minutes of 14.4 volts every 20 hours from the PD is more about stirring electrolyte than desulphating the plates. It is better than nothing but...it just can't do the deed.
BFL13 has a great thread on recovering sulphated batteries. A good temperature compensated hydrometer should be used.
Be sure to NOT expose the control boards in your RV to anything over 15.4 volts.
The absolute minimum amperage for equalization is c/20 (or 5 amps per 100 amp-hours).
You may need to "direct connect" the panels to the battery (i.e. do not use a charge controller). A sulphated 12 volt jar will laugh at 15 volts of equalization charge. 16 volts may be needed.
