amperage boost from alternator!

Bitumin Surfers · Member

amperage boost from alternator!

03_Troopy · Guru

Bitumin Surfers wrote:
Hi Techies, tests carried out today confirmed that the alternator is working as designed.
* The output at the tug battery with no engine running - 12.5 volts
* The output at the battery when engine running - 14.1 volts
* Voltage at Anderson plug at rear of tug with engine running - 14.1 volts
* Voltage at the DC to DC charger on 5th wheeler - 13.4 volts

Auto elec contacted the battery management manufacturer during testing for guidance as to settings on charger. Suggestion was to alter settings on charger but auto elec reluctant to make changes. The battery management manufacturer has advised me that he will travel to my home in Gippsland early next week to make any changes or to change out charger.

Will continue post after next weeks adjustments.

-- Edited by Bitumin Surfers on Thursday 12th of May 2016 06:45:26 PM

-- Edited by Bitumin Surfers on Thursday 12th of May 2016 06:46:03 PM

Was that measurement made under load? ie was the anderson plug connected, and the DC-DC charger drawing current. The low voltage at the DC-DC charger indicates too high a voltage drop over your supply cables. Either caused by too small a guage wire, poor conductivity at the connections, or both.

dorian · Guru

03_Troopy wrote:
Was that measurement made under load? ie was the anderson plug connected, and the DC-DC charger drawing current. The low voltage at the DC-DC charger indicates too high a voltage drop over your supply cables. Either caused by too small a guage wire, poor conductivity at the connections, or both.

The OP's report is ambiguous. It is not clear whether the voltage at the charger is an input or an output, at least not to me.

PeterD · Guru

The 13.4 V would be the input to the charger. Firstly he is not charging a flat battery, the OP voltage would be higher than that. Secondly he is carrying out the tests I suggested, that is to look at the voltage drop along the supply line to the charger.

The 14.1 V at the Anderson plug looks to me that the reading was taken with the charger disconnected. I would expect some drop when the heavy current was flowing through it.

03_Troopy · Guru

PeterD wrote:
The 13.4 V would be the input to the charger. Firstly he is not charging a flat battery, the OP voltage would be higher than that. Secondly he is carrying out the tests I suggested, that is to look at the voltage drop along the supply line to the charger.

The 14.1 V at the Anderson plug looks to me that the reading was taken with the charger disconnected. I would expect some drop when the heavy current was flowing through it.

Yep, that's how I read it too, but I see Dorians point. And I agree with Anderson Plug reading being under no load, to get the same voltage at the rear as at the alternator (unless he's got 0B&S cable running to it biggrin and the multimeter resolution is pretty poor)

Bitumin Surfers · Member

Hi Techies, we are almost there. The battery management manufacture arrived at my home as promised and carried out a number of changes to the settings on the installed charger in addition to trying a couple of different chargers all without any significant change. Finally he moved the charger from the fifth wheeler to under the bonnet of the ute with startling results, the charger was now pushing 57 amps at 13.7 volts into the lithium iron batteries in the fifth wheeler. Today I cooked food in the microwave and the charger pushed 67 amps into the system during the cooking cycle. We have a winner. the DC charger will push more power than it will pull.

Just one minor hick-up remains, the charger will not feed any power into the batteries if the engine has been turned off and the Anderson plug detached. I have to reset the the charger by connecting the Anderson plug, starting the engine then pulling out and replacing the fuse on the negative side of the circuit between the charger and the output circuit to the lithium iron batteries. The link remains however when the Anderson plug is not disconnected and the engine turned off and when the engine remains running and the Anderson plug is disconnected.

The battery management manufacture has contacted the DC chargers manufacturer to see if they have a solution to the problem. Will post results if and when I receive any further advise to resolving this minor hick-up.

PeterD · Guru

Good to see you have sought assistance from someone who knows the equipment. You posed a problem that involves equipment that is foreign to users of the common installations in vans.