17' Series Batteries & solar

[Heydon]

Hey All,
I'm still getting my brain around batteries. We have the whatever Jayco supplied on the 2017 Expanda OB - maybe 150w solar and 105ah battery. We've always found this adequate for a night here and there but we hit it pretty hard last week when the we had 2 days of rubbish weather and were stuck in the van amusing the kids (lots of TV).

Am I understanding it right the during the day (average crap Vic day here at the moment) the readout on the solar manager thing is high - over 13v then the battery 'settles' into the evening to 12.7 while there's no solar input? I'd never really taken much notice but now I have and it seems to be 12.7 or 12.8v when I go to bed and in the morning it's usually 12.7 or even as low as 12.5v with no additional load other than the j35B and the solar controller working. Is that normal or is the batter suffering? it copped some massive vibrations on a trip 2 weeks ago.

Further to that we're considering adding another solar panel. I'll search that up and decide if it's a job for me - but i can't see a junction box on the roof. I wonder if the connectors are accessible under the existing panel. Is it true that if the panel is 150w I should add another 150w panel? I read the wattage shouldn't be mixed.

Lastly, has anyone used an itechworld lithium battery recently? The say 'drop in' which is appealing but the company has been unable to respond to a few questions I sent them which doesn't instill much faith in potential after-sales communication.

many many thanks!

 

[BaxnRach]

12.5v is fine, I'm no expert but I'll suggest another battery, so you have more power stored for those crappy days, rather than another solar panel.
I'm also interested in the Itech 120ah lithium battery, that'll have roughly twice the storage capacity than our 100ah AGMs

 

[Heydon]

12.5v is fine, I'm no expert but I'll suggest another battery, so you have more power stored for those crappy days, rather than another solar panel.
I'm also interested in the Itech 120ah lithium battery, that'll have roughly twice the storage capacity than our 100ah AGMs

Thanks Bax, definitely considering both- more storage and more solar to get it there faster. I’d assume that loss of 0.1 or 0.2v overnight isn’t of concern then? Maybe still settling?

 

[MDS69]

Check that your solar regulator is up to the task of the additional 150W. Need to look at open circuit voltage as well.

 

[Heydon]

Check that your solar regulator is up to the task of the additional 150W. Need to look at open circuit voltage as well.

Cheers - if it wasn't evident in my earlier post I'm verrrrrry green with this stuff so while I appreciate your reply I suspect you knew this was coming..... can you please explain what you mean by open circuit voltage? and what do I to check?
My understanding of the TPS1230 (PWM) is that it can cope with 30amps and up to 400 watts of solar. It's what Jayco used then and I've read it's not as good as the MPPT variety but functional. It's not out of scope to chuck a better one in with the right recommendations if there's a better match up.

 

[Drover]

BY your figures its really all good, you need to worry if your battery is down to 12.2 often ................ to add another battery have a read of this https://caravanchronicles.com/guides/how-to-connect-two-batteries-in-parallel/
It explains it all in easy to read and understand language and also lead onto other information . The PWM regulator while not the greatest is better than a lot of them, for a far better charging source a MPPT Regulator is far more effiencient...

Adding another battery and a portable panel will give you more storage and charging capacity, my ALDI panel has been doing a good job for a number of years now and gets well used for a few months each year..... Big Mal has 210ah of Gel battery, 200w on roof, 120w of panel on the ground and runs TV, Fox and VAST STB's along with fans, diesel heater, lights and charging phones and stuff with a 400w for charging cam and laptop every other day............. Start to worry by day 3 of full overcast but have a LRPS just in case.

 

[Heydon]

BY your figures its really all good, you need to worry if your battery is down to 12.2 often ................ to add another battery have a read of this https://caravanchronicles.com/guides/how-to-connect-two-batteries-in-parallel/
It explains it all in easy to read and understand language and also lead onto other information . The PWM regulator while not the greatest is better than a lot of them, for a far better charging source a MPPT Regulator is far more effiencient...

Adding another battery and a portable panel will give you more storage and charging capacity, my ALDI panel has been doing a good job for a number of years now and gets well used for a few months each year..... Big Mal has 210ah of Gel battery, 200w on roof, 120w of panel on the ground and runs TV, Fox and VAST STB's along with fans, diesel heater, lights and charging phones and stuff with a 400w for charging cam and laptop every other day............. Start to worry by day 3 of full overcast but have a LRPS just in case.

Thanks Drover that was a good read. What are your thoughts on adding a new battery to the other one? I know it says buy them at the same time. The battery seems to be in good health and I accept that it might bring down the performance of a new (cheapies) AGM but I’d still gain a decent amount of power storage.
OR might the preference be to write off the old battery and put in a single 250-300ah agm for around the $500 mark?
I don’t think I’m ready to spend/risk lithium yet, I don’t feel it’s worth it for our setup unless we go the whole hog. The whole expensive hog!
Cheers.

 

[Eddii]

Drop in replacement Lithiums are getting cheaper. 1x105ah LiFePo will equate to 2x 105ah AGM [rule of thumb ok ] Plus have you lifted one of those 300ah AGM battery you mentioned? Save yourself some weight

 

[Eddii]

I'm not sure about the internal BMS on those lithium batteries though. Maybe look into ones with a longer warranty period.

 

[Heydon]

That’s my concern. I’ve heard completely opposite reviews of the itechworld lithium’s which are around $800 at the moment. I’d sent them some questions and heard nothing back which backs up my concerns (from what I’d read) about their after sales service.
The agms I’m looking at are around 70kg so I’d hope once a mate had helped me wedge one in I’d not have to deal with it for a few years!

 

[Eddii]

Try this one
https://www.evworks.com.au/winston-battery-lp12v90ah-lifepo4-cell-12v-90ah
No internal BMS though, plus it's uses prismatic cells (which is better apparently).
Spoke to the owner of the shop and he recommends to use a low battery cutoff (bat saver).
I have one in my ute. Running CTEK Dc to DC charger + solar. Not an ideal battery charger but as long as your charger does not go above 14.4v then all ok.
These batteries don't like high voltage and very low voltage. He was nice to talk to

 

[Drover]

If your going to be using your van for 6 months or more a year and can afford the Lithium Batteries and compatable charger then go for it, otherwise they are just an overpriced bit of bling really.
There is 2 yrs difference between my GEL's, might be some small loss on a bench test but out in the wild you wouldn't notice ......................they must be same type (AGM, GEL etc) and same capacity, obviously if the older one is too old then no, If I hadn't replaced the aux battery in ute I would have put the van Gel in the ute and 2 new jobs in the van, everything running nicely so far and they get used for a about 4 mths of the year but are always kept charged by the solar.

2 batteries is way better than one big bugga that you would need a crane to lift in and out of the boot.....looking at 70kgs.

 

[Eddii]

Go with 2 batteries as per @Drover said. My back hurts just thinking about it hahahaha

 

[Drover]

also if one croaks it you still have power not so with big job.....

 

[Heydon]

Thanks Drover that's something I hadn't thought of re: one carking it. We plan a bit of a trip, maybe 4 months and definitely watching the $$. It seems that with vanning it's hard to know when to stop spending and it can easily get out of hand!
I think the 3 AGMs and an extra panel will be a good fit for our needs. The money saved can go towards increasing our ATM (for the battery but also for everything else!)

Is it imperative that batteries be in a battery box? The current one has a broken strap and takes extra space, I reckon I could come up with a more suitable option with straps and yoga mat material....

 

[Drover]

Best to have them in a spot where you have easy access, don't have anything stored around them and that nothing can contact the terminals, have seen tent pegs cause the van wiring to have a melt down........ One of mine is in its own little cupboard in the boot on a slide while the other is in a box in the boot, I was going to increase the size of the battery cupboard and add a twin slide but once I saw the price of the things I thought a plastic box was a better idea......
When AGM's or GELs go feral they get very warm and expand unlike the old wet battery which goes KaBloomie....... 3 x AGM which I assume to be 120ah is a heck of a weight, you would need to spread them a bit a 100kg in one spot is a bit much.

 

[Crusty181]

That’s my concern. I’ve heard completely opposite reviews of the itechworld lithium’s which are around $800 at the moment. I’d sent them some questions and heard nothing back which backs up my concerns (from what I’d read) about their after sales service.
The agms I’m looking at are around 70kg so I’d hope once a mate had helped me wedge one in I’d not have to deal with it for a few years!

My second AGM came out of my last 5 years old Expanda and it went into the current van 4 years ago with the new battery in the new van. (Probably due to be tested actually). I look after them, careful of usage and the van is always connected to 240v at home. In simple terms (not cause your simple, more cause I am) the MPPT is newer tech and is more efficient so blow for blow will marginally out perform the older simpler PWM. The most significant difference is the PWM charges at just above the current state of battery charge, so that means slowly and with a deeply discharged battery it will take forever. The MPPT makes use of the panels maximum available voltage, so much like a smart charger will pump as much charge into the batteries as it can find, backing off as the state of charge approaches 100%.

There are many varying MPPT brands Victron regarded as the goto, but they are expensive. I use one for my portable panels, and its really good. In the van I have a cheaper but bigger 40amp Epever Tracer, off Ebay for around $150ish. The Epever Tracers have great reviews and Ive found it good. The MPPTs (and PWMs) are all simply straight forward 4 wire swap outs; nothing complex and you'll see the 4 wires in your PWM labelled terminals; 2 in form the panel and 2 out to the battery. Rule of thumb if its a cheap MPPT, then its a PWM

 

[Heydon]

Best to have them in a spot where you have easy access, don't have anything stored around them and that nothing can contact the terminals, have seen tent pegs cause the van wiring to have a melt down........ One of mine is in its own little cupboard in the boot on a slide while the other is in a box in the boot, I was going to increase the size of the battery cupboard and add a twin slide but once I saw the price of the things I thought a plastic box was a better idea......
When AGM's or GELs go feral they get very warm and expand unlike the old wet battery which goes KaBloomie....... 3 x AGM which I assume to be 120ah is a heck of a weight, you would need to spread them a bit a 100kg in one spot is a bit much.

Sage advice. The area the batteries will be is reserved for the batteries, J35 and inverter. It’s under one of the kids beds so not inaccessible but not a convenient everyday storage spot. Just adding one more battery- to match probably 105ah (pretty sure that’s what the other one is) so I think around 60kg.

 

[Boots in Action]

12.5v is fine, I'm no expert but I'll suggest another battery, so you have more power stored for those crappy days, rather than another solar panel.
I'm also interested in the Itech 120ah lithium battery, that'll have roughly twice the storage capacity than our 100ah AGMs

Hi @BaxnRach , the voltage chart is for GEL batteries only. If you have AGMs, they charge to a higher voltage and the J35B needs to be set for AGM. Attached is the correct voltage soc for AGM batteries.