Charging

[rawsondsr]

Whats the difference in charging times with the following methods?

Standard engine alternator

travelpower

generator

based on say a 50% charged 600 amphour battery bank?

[WotEver]

8 minutes ago, rawsondsr said:

Whats the difference in charging times with the following methods?

Standard engine alternator

travelpower

generator

based on say a 50% charged 600 amphour battery bank?

Very little. 

[Alan de Enfield]

8 minutes ago, rawsondsr said:

Whats the difference in charging times with the following methods?

Standard engine alternator

travelpower

generator

based on say a 50% charged 600 amphour battery bank?

Charging from 50% to 80% will be slightly (probably minutes) the larger the output of the charging method.

From 80% to 100% they will be pretty much identical assuming they are charging at the same voltages.

[mrsmelly]

Travel power is nothing to do with charging batteries directly. It can be used to power a mains battery charger but would be the same then as via a generator'

[Tony Brooks]

But a battery charger might have settings that provide a higher absorption voltage than "standard" so as long as the absorption period is not timed and that adaptivity charging does not foul things up the absorption period may be shorter. E.G. if you have batteries that are happy at 14.8 volts then that 0.4 volt over the typical alternator charging voltage will speed things up but as said not to a major degree.

Using something to power an adjustable battery charger may well have advantages when to comes to needing to do equalisation. The alternator is exceptionally unlikely to allow that and a generator may not. Most suitcase generator 12V "battery charging output" seems to be unregulated so it would reach equalisation voltage eventually but that output is so low it would probably take days or weeks to get there with a 300 Ah discharge. The 12V output is best ignored.

[Detling]

3 hours ago, Alan de Enfield said:

From 80% to 100% they will be pretty much identical assuming they are charging at the same voltages.

from 80% to 100% the batteries control the charge current and it will reduce gradually, usually over 3-4 hours until the current is about 1 amp per battery, then we give up and say they are fully charged.  If you continued to charge you will get more in, you could get maybe 3-4 amp hours charge in the next hour but really life is to short for that to be worth it, not to mention the cost per amp hour.

[Alan de Enfield]

35 minutes ago, Detling said:

from 80% to 100% the batteries control the charge current and it will reduce gradually, usually over 3-4 hours until the current is about 1 amp per battery, then we give up and say they are fully charged.  If you continued to charge you will get more in, you could get maybe 3-4 amp hours charge in the next hour but really life is to short for that to be worth it, not to mention the cost per amp hour.

The difference would be a battery charger giving 14.4-14.6v and an 'old alternator' 13.8-14.0v. It needs a highish voltage to get that last bit squeezed in

[ditchcrawler]

So if the OP has a 30 Amp charger and a 150 Amp engine alternator they are going to take about the same time? More info needed. 300Ah is going to take a long time what ever you use

[Detling]

10 minutes ago, Alan de Enfield said:

The difference would be a battery charger giving 14.4-14.6v and an 'old alternator' 13.8-14.0v. It needs a highish voltage to get that last bit squeezed in

I must admit I assumed a modern alternator giving at least 14.4V, It also depends if flooded wet LA, type 1 AGM, or type 2 AGM. as the volts differ, put 14.8 on type 1 AGM and they are wrecked in minutes.

 

PS I don't know the difference between AGM types but type 1 has a max volts of 14.4 and type 2 14.8 volts max. They both will swallow more amps up to about 90% than a wet LA will for the same voltage. after that the waiting game commences (tail current). 

[rawsondsr]

So what is the main benefit to a travelpower or generator, whether petrol or diesel (im aware of the dangers of a petrol genny)

[Alan de Enfield]

3 minutes ago, rawsondsr said:

So what is the main benefit to a travelpower or generator, whether petrol or diesel (im aware of the dangers of a petrol genny)

If you are referring to a 'proper' built in water cooled generator then that is by far the best option.

If you are talking about a petrol powered generator sat on the bank than a travelpower is better.

A travel power requires you to run a 'big' main engine to generate mains voltage, if you are then using is purely to run a battery charger, you may as well just use a standard alternator.

If you want 220v for running a washing machine then the order would be :

1) Built in genny

2) Travelpower

3) Alternator with inverter

4) Portable generator.

 

Other opinions are available.

[nicknorman]

1 hour ago, rawsondsr said:

So what is the main benefit to a travelpower or generator, whether petrol or diesel (im aware of the dangers of a petrol genny)

Answering your question directly, the main benefit of a travelpower or generator is an ability to generate electricity at mains voltage!

But if you meant “over an alternator” then firstly, an alternator tends to be less powerful. Secondly you need an inverter to run mains power stuff. Thirdly, most boat alternators aren’t really designed to produce their full output for very long - they overheat. And with a severe overheat caused by prolonged operation at high output, they fail.

[MtB]

On 3/22/2018 at 18:26, ditchcrawler said:

300Ah is going to take a long time what ever you use

Point of Order...

With an appropriately sized charger, raising a battery from 50% to 100% takes the same amount of time regardless of battery size. 

[Robbo]

1 hour ago, nicknorman said:

Thirdly, most boat alternators aren’t really designed to produce their full output for very long - they overheat. And with a severe overheat caused by prolonged operation at high output, they fail.

I would highlight that the wording is more like “most alternators installed in boats”.  A alternator from the likes of Mastervolt is designed for charging batteries and provide the output for long periods of time.

You can however help your bog standard alternator by keeping it cooler (reducing the temperature of the engine compartment, increasing ventilation, etc.)

[Sir Nibble]

On 3/23/2018 at 21:33, Robbo said:

I would highlight that the wording is more like “most alternators installed in boats”.  A alternator from the likes of Mastervolt is designed for charging batteries and provide the output for long periods of time.

You can however help your bog standard alternator by keeping it cooler (reducing the temperature of the engine compartment, increasing ventilation, etc.)

A mastervolt alternator is a prestolite unit with a mastervolt sticker on. Much the same as leece neville. I have been heavily involved with a high end marine alternator range from the USA and it's built from Delco components. 

[smileypete]

On 3/22/2018 at 14:31, rawsondsr said:

Whats the difference in charging times with the following methods?

Standard engine alternator

travelpower

generator

based on say a 50% charged 600 amphour battery bank?

Main thing is not to under charge too much, otherwise significant 'sulphation' will reduce capacity but also increase charge time as the charge current will go in more slowly.

Proper fully charging a batt needs correct charge voltage - as stated by the batt mfr  - and enough time for the charge current to 'tail off' and stabilise enough at a reasonably low level.

Doing this every day of the year is impractical, so a full charge every few days seems OK for most people, with a lesser daily charge in between if needed.

When new lithiums get cheaper they'll avoid the need for this madness, there's some good second hand bargains around by the looks of things, but they're not usually 'plug and play'...