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Re: 4300 Alternator Low Current

PostPosted: Mon Feb 06, 2012 4:51 pm
by marco
Not sure I understand that. Generally in my app I am charging my batteries at night on the Xantrax 3 stage charger. When I am on the road I just need the alternator to keep up mostly. For the odd night I am on the batteries I can fire up the genset to top off the batteries (i.e. go through the absorbsion phase). I will keep my batterys charged properly most of the time (i.e. 355 days out of the 365days in the year it is on the Xantrax at night and most of the days too)

The Bosch will do this just not a good job of charging them when flat. The set point is too low to charge them up. Not ideal. I do want my three stage alternator back but you are not giving me much help working this issue.

Anyway here is some math.

Batteries $2000
Ample Power Alternator $1500
Bosch Alternator $280

OK my last set of Batteries lasted me 9 years. 6 of which I used your alternator on (although it has not really worked right for the last 18 months I was just too busy to dig into the problem). Even if the battery life is halfed (not likely since I ran for three years on a regular alternator 160A Prestolite thing) it is still cheaper to replace the batteries more often.
The automotive alternator has a bit of a high float voltage but as a percentage of time the batteries are on it is small so not likely to hurt much. I do about 8000 miles of motorhome driving a year so the actuall amount of time spent at the higher voltage is very small in the scheme of things. I am not using the alternator as the primary means to charge these batteries.

Marco.

Re: 4300 Alternator Low Current

PostPosted: Mon Feb 06, 2012 5:08 pm
by Coulomb
You may be able to purchase a "dummy" internal regulator that holds the brushes but brings out the field for connection to an external regulator. Delco has them, maybe Bosch does.

Re: 4300 Alternator Low Current

PostPosted: Wed Feb 08, 2012 12:37 am
by marco
This will get me on my next trip. I am going to have my 4300 rebuilt and put it back in. One trip on the regular alternator will not hurt my batteries. As i said it is more to stop the batteries discharging than to recharge them i will look for the brush adaptor. Probably not too hard to rig one up either.

Re: 4300 Alternator Low Current

PostPosted: Wed Feb 08, 2012 11:47 am
by Coulomb
The Bosch alternators I've seen make it difficult to modify them for external regulation. Good luck.

Re: 4300 Alternator Low Current

PostPosted: Tue Feb 21, 2012 2:02 am
by marco
There is a brush holder available on the heavy duty bosch and the delco remy SI-28 too. So far the 200A Bosh has charged up my batteries twice on this trip quickly. The set point is a little lower than the correct absorbsion voltage but they seem to fully charge. When I fire up the genset and let the xantrax charge them it says they are charged. So it charges them well but holds too high a float voltage. No big deal for these few weeks but I need to fix it. It is only floating them high wile Iam driving most of the time the xantrax floats at the correct voltage.

I am haveing the 4300 requilt by an alternator shop so I will put that back later... Marco