my bus has a seaRanger 12 volt 30 amp 3 gang charger that has gone bad . it has work well for several years . local rv dealers is not much help . where can a charger with the same quality be found. thank you in advance for any advice .
Lots of good chargers out there. Not sure about the three-gang part, but we're using a Progressive Dynamics 70-amp multi-stage charger with great results. Here's a link to the info page: https://www.progressivedyn.com/rv/power-converters/pd9200-series-rv-power-converters/pd9270-70-amp-rv-convertercharger
We got ours on Amazon, but there are a number of places selling them. They also make a smaller model if you don't need 70 amps. We're using the 9270 since we have about 780 Ah of capacity and Trojan recommends about 10% charge rate.
Google is your friend. https://www.google.com/search?q=30+amp+3+gang+battery+charger&ie=utf-8&oe=utf-8&client=firefox-b
https://www.batterystuff.com/battery-chargers/12-volt/samlex-america-12v-30-amp-3-bank-automatic-smart-charger-sec-1230ul.html
If you don't need the three gang feature (simultaneous charging and monitoring of three separate battery banks, common on boats but not on buses), then there are a ton more available, like the one mentioned above. I usually buy from this guy: http://www.bestconverter.com/
The Sea Ranger was a charger only it wasn't a converter, mine lasted 20 years,Guest and Promariner are good replacements the RV stuff is not that great IMO