converter evolution

[david craft]

i saw some earlier chats on converters styles ...thought i throw in some history. the earlier rvs had convection style heaters and no 12 volts appliances , just 12 volt lighting and 110 volt lighting. the next stage added forced air furnaces with a transformer and diodes to run a 12 volt motor but no provision to supply that power to the rest of the coach. then the first converters came on the scene. they would run the lights and furnace but you had to switch between the converter or the battery for the power source to the load. then they came out with a converter that had a relay to switch the load for you but still no provision to charge the battery. then a fully a fully automatic converter came next but it only had a 10 amp circuit for charging. thats the story for the "linear style" converter. there is the "ferro resonant" converter that came along in the 70s i believe...famous for noise, heat, but convenient for only having 2 wires to hook up. the latest generation is the "switch mode" ...quiet, efficient, high output for charging and loads, no ac ripple. they actually boost battery life. to see if your converter charges your battery, just plug in the coach and hook your volt meter to the posts. anything over 12.8 volts dc is charging current. fully automatic chargers started in about 1975. ive seen the ferro resonant in earlier travco and airstream models. hope you enjoyed the read.

[John "T" Nordhoff]

 Yep some of those older Converter/Chargers were bad about overcharging and cooking your RV House battery. They were like a constant 13.6 or more volts and hummed and ran warm.

 The ONLY way to go nowadays is to invest in a modern 3 or 4 stage computer controlled so called SMART Charger as their quality has improved plus prices are coming down. They start out at 14+ volts BULK charging then slow down to 13.6 volts ABSORPTION charging then settle down to a 13.2 FLOAT charge level plus some have an automatic Desulfation Cycle. Some ones I like are Progressive Dynamics Intell Charge and Best and Xantrex. Check them out on E Bay etc. Also some have settings for Lead Acid or AGM batteries. AGM are more sensitive to charging so if you go that route Id want a Charger that has an AGM setting. 

 John T

[Jim Stoltz]

Thanks. I'll look into that. The alternator charges the house batteries, but the converter doesn't charge the truck battery.

I left my "smart charger" hooked up to the truck/chassis battery for the past 24 hours. It eventually said "FUL" on the display, meaning it thought that the battery was fully charged, but it wouldn't crank. It would only crank when the charger was in the "75 amp" start mode. I think the battery is toast. I might have to bring it back to Wally World for replacement.

[david craft]

sure power has a great device. bi-directional relay(model #1315a).  its simply connects the batteries(coach and chassis) if it senses charging voltage from either direction.  its got the good 100amp relay so it can handle some load.  the down side is they had issues in the past of over heating.  they really need to step down the current to the coil after it engages so it dont run so friggin hot during long periods of activation but thats another issue altogether...

[Jim Stoltz]

One of the first things I did when I got my '84 was replace the converter. The new one has the "smart charging" algorithms, gives off less heat, is half the size and 1/4 the weight. One thing it does not do, however, is charge the truck battery. This is disappointing because I'm currently having issues with the 'new' (December 2015) truck battery. Either something is training it or it's no good. I don't have a switch to connect the house batteries to the truck battery. Suggestions for doing this would be welcomed!