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peacola
03-28-2008, 02:37 AM
Getting ready to begin '07 Sprinter conversion. I'm concerned that overnight campground hookup may not completely recharge house batteries, especially if I dry camped the night before. Is it possible to feed AC to the converter/charger from the alternator while driving?

If not, what size solar system would be needed strictly for recharging?

sikwan
03-28-2008, 06:34 AM
Getting ready to begin '07 Sprinter conversion. I'm concerned that overnight campground hookup may not completely recharge house batteries, especially if I dry camped the night before. Is it possible to feed AC to the converter/charger from the alternator while driving?

If not, what size solar system would be needed strictly for recharging?

Never really thought about tapping straight into the alternator. :hmmm:

I wouldn't think there would be a problem, but...

1. I don't even know if the output from the alternator is 110ACV. I believe the converter/charger has a minimum voltage to be operatable.

2. Are you running 24V bank of batteries? If not, why not just charge the entire bank of the batteries using the 12V (actually 14.4V) without going through a conversion?

3. If you were to connect the converter/charger input to the alternator, you would have to make sure that it is disconnected before connecting it to shore power.

How many batteries are we talking about?

The thing about solar is it gets expensive for any decent size array of cells to do any good and that's only if it's sunny. I would just put money into a Honda or Yamaha petrol generator.

OrioN
03-28-2008, 02:38 PM
Is it possible to feed AC to the converter/charger from the alternator while driving?



Ummmm... the house bank is 12v and can be charged 'directly' from the alternator (via an isolator switch setup) naturally. There is no need to use any charger for this method.

And, charging from 'shore power' (campground) is the best way to fully charge your house bank with a charger setup, assuming your charger is high rated (over 40A).

At best, the Sprinter Alt will pump out an average of 40A of current at highway speeds, so if you have one 200A house battery and it runs down to the recommended 100A level (less than that and invertors don't run and the battery life is greatly reduced) then you will need 2.5hrs of drive time to recover. (Actually, since Alt's only bulk charge and cannot Float charge, you will only get the battery to 175 amps at best, so again Shore & Genset charging are best here).

This is not an easy subject, and probably not going to get the info you really need on this forum. GOOGLE!!

peacola
03-28-2008, 07:54 PM
Let me provide a little more detail. And this is coming from a newbie.

While doing an overnight at a campground that provides AC, I would use it to power a microwave, roof AC, computer and coffee pot while recharging the two or four 6volt golf cart batteries though an converter/charger. The batteries would power the refrigerator, roof fan and DC lights.

If I make stops where power isn't available, thereby draining my batteries, would an overnight stop at a campground providing AC be sufficient to recharge them? If not, then I'm looking for alternatives and I don't want to resort to a generator.

I gather from your replies that recharging from the alternator while driving is not done.

KenB
03-28-2008, 08:51 PM
recharging from the alternator while driving IS done, but not at the rate of the full alternator output... a 200 amp alternator does not charge at 200 Amps on the highway in top gear... also you need an isolator and for best results you also need a battery tender such as is used on water-craft with onboard/shore power capability.

You wouldn't generally take AC from the alternator unless it were a unit made for that. At least one is made for the MB-5 cylinder diesel such as in the T1N sprinters (USA, prior to 2007) and I believe that it is about 5400 watts of AC, plus 12v to run the van and fits in the place meant for the stock alternator. Such units would not be meant for stationary use unless the van is also fitted with a control unit that boosts RPM... EGR valves and the passageways to/from them do not like idling conditions.

A good shore/convertor unit should get your batteries back up over-night.

Thanks,
Kenneth

sikwan
03-28-2008, 11:57 PM
If I make stops where power isn't available, thereby draining my batteries, would an overnight stop at a campground providing AC be sufficient to recharge them? If not, then I'm looking for alternatives and I don't want to resort to a generator.

Another thing is batteries do not like being totally discharged.

As KenB mentioned, you could probably charge all the batteries during an overnight stop, but this would depend on the condition of the battery (because of the deep discharging). I think it's possible to drain your batteries, take a drive while charging your batteries to your next stop, and do the overnighter charging.

peacola
03-29-2008, 12:36 AM
Initially, I'll use two 6 volt golf cart batteries, along with an Intelli 60 W converter/charger and a Sure Power separator. If more amp hours are needed, then I'll add two more batteries.

If an overnight charge will be enough to fully recharge them, I'll be a happy camper. Hopefully, I'm worrying needlessly about keeping my batteries up and running.

I want to travel, see some of this country's beauty and visit my children on the west coast. I'd like to be able to do this without having to hook up and recharge each and every night.

I spent a week in a 1930 vintage log cabin by the Sandy river in Oregon with my grandson. Each morning we would "wake up the Sandy" before everyone else awoke. I'd love to do that one morning in a Sprinter.

OrioN
03-30-2008, 10:58 PM
Food for thought...

Your 2 house batteries i assume (100A each) will give you about 200A capacity. Only 100A will be available for use through the inverter as any 'good' inverter will not run below a certain voltage. Any applaince hooked up to your 60W (5A draw) inverter will last about 20hrs. BUT, 60W is peanuts, it will barely run a 15" Notebook alone...