Working on my solar plan - need battery input, please

alliemac9 wrote:
I've read some accounts of people going to lithium, but I don't need to be a beta tester. :P

They're proven but they don't act like lead acid batteries so there is a re-learn of some things (BTW, the one's you'd use in an RV are not like the laptop, cell phone, EV, Airbus batteries).

Bend wrote:
Workout the bugs, logic & settings with the old batts before you lay down the $$$ on a new set. Might save you from a large headache or 3.

X2

Workout the bugs, logic & settings with the old batts before you lay down the $$$ on a new set. Might save you from a large headache or 3.

I actually contacted a wholesaler (Hodgson) and they had a Denver location with both the TMX and TMH available (didn't show the SCS200 on their list, so I didn't ask for it).

Now the question is: my batteries aren't dead yet...even though I'm doing a big solar overhaul, I assume I should wait 'til they die to replace them?

The TMH was rather mythical 2 years ago when I was shopping. Trojan listed the batts but dealers did not have them nor had heard of them. I hope that has changed.

Get the TMH if you want max capacity. More lead, more capacity. Probably better longevity.

Thanks, all, for the input!

A couple of you mentioned the Trojan 27TMX. I'm curious if you understand the difference between that and the 27TMH (since I probably don't)? The TMH appears to have 10 additional AH at the 20-hr rate in the same size case - is there a drawback to this model?

@MEX - Thanks for the questions! I don't have a super specific goal, but would prioritize maximizing capacity without modifying my battery box. I would like to get good value, if I can, but I'm willing to pay for quality. I ended up purchasing 4x 158W solar panels, so if I understand most people's rule-of-thumb, I have a lot of panel per AH given my battery space limitations. Ultimately, it was a reasonable price ($0.85/W + shipping) and seemed like a sound plan to just buy more watts than originally planned so I could simply mount them flat on the roof and not monkey around with tilting, etc. We are usually on the go a lot and travel more in the fall, so this will hopefully make sense.

We only have a 400W inverter at the moment and have been fine with that. We plan to do more extended boondocking (i.e. one place for a while instead of always on the move), so we can evaluate if it needs to be upgraded in future. I'm not trying to run anything big (microwave, AC), just want to be offgrid without driving (which is mostly how we have been staying charged - covering 5,000 miles over a 2.5-3 week trip).

I'm hoping that by the next time I need to buy batteries the newer lithium technologies will be viable (e.g. www.balqon.com - I could fit 4-5 of those things in my battery box for 1000AH+!!). I've read some accounts of people going to lithium, but I don't need to be a beta tester. :P

alliemac9,

Perhaps now is the time to inquire as to your needs and desires for whatever type of battery. Do you have a list of desired qualities? Why do you seek these qualities if I may ask?

More capacity...longer lifespan...price...value...more CCA (like with an inverter), knowing your goals makes it a lot easier to pinpoint suggestions for you :)

A 8-D would be a lot of capacity if you can get it in there. Mine is just a bear to move.

My grp 27 is only 95 ah.

Box seems made for 3x group 27 but check the width as 19" seems tight. Might need 20".

Compare Trojan 27TMX

http://www.trojanbattery.com/product/27tmx/

2 deep cycle group 27's should work and are equivalent in 20 hour amp rate to 2 golf cart batts. Take a look at Trojan's 27 TMX and SCS200.