Lithium house batteries : Lead acid engine battery

[Pete7]

Which BMS is that?

Its a Daly 150A with bluetooth. Seems reasonably accurate when comparing the numbers to a separate Sterling Power Management monitor and the display on the inverter which also gives voltage and wattage being consumed.

Pete

 

[sailaboutvic]

My house and starter battery use to be connected by a VSR , when I replace my house with lithium I disconnected the VSR use the alternator to charge the LA starter battery and fittered a Victron B2B to charge the lithium from the starter battery ,
I have to say I only used the B2B once since fitted it , my panels is doing the job nicely.

 

[gregcope]

Its a Daly 150A with bluetooth. Seems reasonably accurate when comparing the numbers to a separate Sterling Power Management monitor and the display on the inverter which also gives voltage and wattage being consumed.

Pete

Thanks

 

[Poey50]

We have the same Prestolite Leece Neville manufactured alternator. It is a standard fit on my Perkins M92B engine. To get more volts out of it (24v boat, 60amp output at 24v) we installed a Sterling smart reg. This has battery temperature sensing. It did raise the voltage under bulk charging but the inbuilt temperature sensor would cut out the external reg fairly quickly. We persevered with it but it really didn't add a lot of charging capability due to the time spent switch off by the temperature sensor. I tried disconnecting the temperature probe for a while and it worked fine. After a few weeks, out of interest, I removed the alternator and stripped it down. The windings were black. It still worked but clearly had been running very hot. I installed the spare alternator with nice shiny copper windings and didn't bother reconnecting the Sterling reg. Clearly driving this normal alternators hard and hot does have consequences.
It makes sense that Balmar heavy duty alternators are equipped with oversized cooling fans as well as other more robust solutions.

Those who seem to make direct charging of LFP by temperature compensated alternators work find some way of dialling back the bulk voltage since LFP keeps them almost permanently in bulk. One person swapped out the internal regulator for a 13.8v maximum. One prominent member of the 12 volt Facebook Group just relies on the voltage drop on a longer and thinner cable selected to stay within cable temperature limits, taking advantage of the flat LFP voltage curve. Both have an above-average knowledge of LFP requirements... it's not for everyone and wasn't for me. And while these methods will provide charge and protect the alternator, they don't stop charge and the LFP will keep devouring anything above 13.5 volts until the BMS does a high voltage disconnect so it needs either manual intervention to stop charging or a voltage sensitive relay on the field wire to shut the alternator down when the target voltage is reached.

 

[pvb]

We have the same Prestolite Leece Neville manufactured alternator. It is a standard fit on my Perkins M92B engine. To get more volts out of it (24v boat, 60amp output at 24v) we installed a Sterling smart reg. This has battery temperature sensing. It did raise the voltage under bulk charging but the inbuilt temperature sensor would cut out the external reg fairly quickly. We persevered with it but it really didn't add a lot of charging capability due to the time spent switch off by the temperature sensor. I tried disconnecting the temperature probe for a while and it worked fine. After a few weeks, out of interest, I removed the alternator and stripped it down. The windings were black. It still worked but clearly had been running very hot. I installed the spare alternator with nice shiny copper windings and didn't bother reconnecting the Sterling reg. Clearly driving this normal alternators hard and hot does have consequences.
It makes sense that Balmar heavy duty alternators are equipped with oversized cooling fans as well as other more robust solutions.

Prestolite alternators are popular in the USA for trucks and buses which haul long distances in sweltering heat in the southern states. They survive well. Incidentally, Balmar alternators are essentially Prestolites with white paint.

 

[geem]

Prestolite alternators are popular in the USA for trucks and buses which haul long distances in sweltering heat in the southern states. They survive well. Incidentally, Balmar alternators are essentially Prestolites with white paint.

Like most manufacturers, you can get uprated alternators for harsh environments. If you look down the list of Prestolite model numbers mine is a simple, nothing special unit. There are units with high temperature rating, large frame, large fan. These are probably the ones that get painted white for Balmar. Mine got painted blue for Perkins?