Battery full %

[shfish]

Apologies to the OP for drifting slightly off topic, but I need battery education....

In my previous vehicle I had a totally reliable refrigeration system , 100ah battery charged by National Luna solenoid system from alternator or 100 watt solar panel, one 50 ltr fridge/freezer. This all worked perfectly, even in 40 plus degrees.

With my new vehicle, my fridge system is different ( draws about 8 ah when cooling) and I bought a new 100 ah battery, still charged by alternator or the 100 watt panel. My problem is, this new battery takes so long to fully charge!! For example, on a recent tour, I started with a fully charged battery, DROVE 11 HOURS, and on arrival found that the battery was down to an estimated 50% ( fridge died about 6 hours after arrival).
When I got home after struggling with refrigeration the whole way, I put the battery on my 4 amp charger. It took about 70 hours to fully charge.
In another test, I ran the battery fairly low and then charged it with the 100 watt panel ( 7 - 8 Amps?) and after 17 hours of reasonable sunlight with no load, it still wasn't fully charged.

So, in summary, it does eventually charge but it charges exceedingly slow. My auto electrician says that this is how the "new"(?) batteries are. I know I'm perhaps a bit underpowered for my fridge but is this slow charging rate normal when it isn't even under load? This battery is quite useless to me.
TIA

[Spiceman]

Apologies to the OP for drifting slightly off topic, but I need battery education....

In my previous vehicle I had a totally reliable refrigeration system , 100ah battery charged by National Luna solenoid system from alternator or 100 watt solar panel, one 50 ltr fridge/freezer. This all worked perfectly, even in 40 plus degrees.

With my new vehicle, my fridge system is different ( draws about 8 ah when cooling) and I bought a new 100 ah battery, still charged by alternator or the 100 watt panel. My problem is, this new battery takes so long to fully charge!! For example, on a recent tour, I started with a fully charged battery, DROVE 11 HOURS, and on arrival found that the battery was down to an estimated 50% ( fridge died about 6 hours after arrival).
When I got home after struggling with refrigeration the whole way, I put the battery on my 4 amp charger. It took about 70 hours to fully charge.
In another test, I ran the battery fairly low and then charged it with the 100 watt panel ( 7 - 8 Amps?) and after 17 hours of reasonable sunlight with no load, it still wasn't fully charged.

So, in summary, it does eventually charge but it charges exceedingly slow. My auto electrician says that this is how the "new"(?) batteries are. I know I'm perhaps a bit underpowered for my fridge but is this slow charging rate normal when it isn't even under load? This battery is quite useless to me.
TIA

Please provide the name and specifications of the new battery and the previous one. Also tell us about the two vehicles.
The new vehicles are equipped with "smart" alternators that do not charge the same as the old ones.

[ChrisH]

Apologies to the OP for drifting slightly off topic, but I need battery education....

In my previous vehicle I had a totally reliable refrigeration system , 100ah battery charged by National Luna solenoid system from alternator or 100 watt solar panel, one 50 ltr fridge/freezer. This all worked perfectly, even in 40 plus degrees.

With my new vehicle, my fridge system is different ( draws about 8 ah when cooling) and I bought a new 100 ah battery, still charged by alternator or the 100 watt panel. My problem is, this new battery takes so long to fully charge!! For example, on a recent tour, I started with a fully charged battery, DROVE 11 HOURS, and on arrival found that the battery was down to an estimated 50% ( fridge died about 6 hours after arrival).
When I got home after struggling with refrigeration the whole way, I put the battery on my 4 amp charger. It took about 70 hours to fully charge.
In another test, I ran the battery fairly low and then charged it with the 100 watt panel ( 7 - 8 Amps?) and after 17 hours of reasonable sunlight with no load, it still wasn't fully charged.

So, in summary, it does eventually charge but it charges exceedingly slow. My auto electrician says that this is how the "new"(?) batteries are. I know I'm perhaps a bit underpowered for my fridge but is this slow charging rate normal when it isn't even under load? This battery is quite useless to me.
TIA

Maybe your new vehicle has a smart alternator that affects the charging of the second battery? If so, you might need a DC-DC charger that is compatible with smart alternators.
Remember the last 20% of the battery takes much longer to charge than the fist 80%.
I have a cheap Bluetooth battery monitor in the trailer battery for the exact same reason, to check the charge levels while driving or on solar worth getting one. https://www.bobshop.co.za/item/59364...saApX9EALw_wcB

It could also be that the new battery has a fault?
BTW a 100W panel wont give you more than say 5.5A at peak daylight times, so roughly will put about 30 amps max back into the battery per day.

[shfish]

Thanks Spiceman and ChrisH, I've learnt something now! Apparently the Navara does have a smart alternator. I had never heard of such a thing!

Seeing as most of my aux battery charging is done with driving when I'm touring, I guess the time has come for a DC to DC charger. The battery is 100 amp - what charger do I go for, 20 amp? Seeing as I've already got a MPPT controller for solar input, can one buy a DC to Dc charger that doesn't have solar option, thereby saving a few rands?
I'm off on the next tour on Sunday - where would I be able to purchase a charger over the counter as I can't wait for an on line delivery?
Thanks again.

[ChrisH]

Thanks Spiceman and ChrisH, I've learnt something now! Apparently the Navara does have a smart alternator. I had never heard of such a thing!

Seeing as most of my aux battery charging is done with driving when I'm touring, I guess the time has come for a DC to DC charger. The battery is 100 amp - what charger do I go for, 20 amp? Seeing as I've already got a MPPT controller for solar input, can one buy a DC to Dc charger that doesn't have solar option, thereby saving a few rands?
I'm off on the next tour on Sunday - where would I be able to purchase a charger over the counter as I can't wait for an on line delivery?
Thanks again.

Something like this :
https://www.livestainable.co.za/prod...4aArW5EALw_wcB

https://summit4x4.co.za/product/12v-...YaAkPdEALw_wcB (this oen has built in solar charger) and yes it's not needed as you already have one.

[Spiceman]

Thanks Spiceman and ChrisH, I've learnt something now! Apparently the Navara does have a smart alternator. I had never heard of such a thing!

Seeing as most of my aux battery charging is done with driving when I'm touring, I guess the time has come for a DC to DC charger. The battery is 100 amp - what charger do I go for, 20 amp? Seeing as I've already got a MPPT controller for solar input, can one buy a DC to Dc charger that doesn't have solar option, thereby saving a few rands?
I'm off on the next tour on Sunday - where would I be able to purchase a charger over the counter as I can't wait for an on line delivery?
Thanks again.

You have to understand that your battery specs are very important at this point. I'm not kowledgeable enough on this subject but to give you an idea: somethig to the effect of a smart alternator cannot charge a deep cycle battery to 100% but a semi deep cycle such as a Royal 1150K will work. Once again; I don't know enough about this specific subject. Forum members such as @fluffy or @ekkekan, there are a lot of members better qualified to put you on the right track.

[dilligafrican]

Something like this :
https://www.livestainable.co.za/prod...4aArW5EALw_wcB

https://summit4x4.co.za/product/12v-...YaAkPdEALw_wcB (this oen has built in solar charger) and yes it's not needed as you already have one.

I would just go for the 30A Victron and be done with it

[shfish]

I would just go for the 30A Victron and be done with it

I read that 25 amp would be max for a 100 ah battery??

[dilligafrican]

I read that 25 amp would be max for a 100 ah battery??

Depends on the battery I guess, but anywhere between 10%-30% of nominal capacity should be fine.

[Fluffy]

I read that 25 amp would be max for a 100 ah battery??

Bump

[ChrisH]

where would I be able to purchase a charger over the counter as I can't wait for an on line delivery?
Thanks again.

Maybe try Current Automation Cape Town

[petewill]

I'm off on the next tour on Sunday - where would I be able to purchase a charger over the counter as I can't wait for an on line delivery?

Go to your nearest Outdoor Warehouse (or similar store) and get the National Luna NLDC-25.

[Fluffy]

Go to your nearest Outdoor Warehouse (or similar store) and get the National Luna NLDC-25.

A truly excellent product that does just about everything, albeit at a price.

[shfish]

Thanks for all the advice.
A couple of questions have been answered...
Firstly the battery is not charging via the alternator because it's a smart alternator.
Secondly, I checked the amperage of my 100 amp panel this morning and it's only putting out 3 amps, so it's somehow stuffed.
I'm definitely going the DC to DC route but that NLDC 25 is beyond my budget. I'll be supporting 4x4 Direct with a Badger 25 charger. They've got in stock in Brackenfell, CT.

[DirtBasher]

Thanks for all the advice.
A couple of questions have been answered...
Firstly the battery is not charging via the alternator because it's a smart alternator.
Secondly, I checked the amperage of my 100 amp panel this morning and it's only putting out 3 amps, so it's somehow stuffed.
I'm definitely going the DC to DC route but that NLDC 25 is beyond my budget. I'll be supporting 4x4 Direct with a Badger 25 charger. They've got in stock in Brackenfell, CT.

I presume you mean 100Watt panel?
3 amps isn’t stuffed, I have two, in summer my one is around 3.4
Winter up to 4.8A
Most are around 5.6Amps
My 160watt panel produces 8 amps

[shfish]

I presume you mean 100Watt panel?
3 amps isn’t stuffed, I have two, in summer my one is around 3.4
Winter up to 4.8A
Most are around 5.6Amps
My 160watt panel produces 8 amps

Oops, ja, 100 watt. Thanks for the info!