thanks for the reply , i will try to explain what i aim to do , i have 2 x 6v agm batterys that are connected to the elektroblock which charges them
there is also a
pwm solar charge controller connected directly to these batterys and 3 x 100w
solar panels . now what i would like to do is change the
solar charge controller to a
victron mppt 150 35 which i have and to change the 2 x agm batterys to my lithium ion batterys i think it should be ok using the agm setting on the electroblock but i would just like a little advice on this .thanks for your help
I know little about the Electoblock units so can't comment on that. I do know some are very basic and some are pretty advanced and well upto the job of charging what you want to fit and have Lithium Settings. Which you have though I don't know. Some Hymer/German Van owner may be able to advise further on that?
For
Solar, you say you have the
Victron 150/35 already. That is well OTT in terms of supporting the 3 100W panels. If you hadn't already have got the 150/35 I would have said get a 100/20. If you don't intend to expand beyond the 300W of Panels and want to save money you could likely sell the 150/35 for a fair bit more than a new 100/20 would cost.
You will consider how you will protect the Batteries against charging at low temp. It sounds like your batteries are inside the vehicle so shouldn't get very cold, but be aware that allowing a Lithium
Battery to charge below 0C is the death knell for it. Some batteries have heaters that come on to deal with very low temp charging; some have a BMS with low temp charging; plenty claim to have protection but don't really. Do you know what system YOUR batteries have to protect themselves?
Trevor mentions about topping up the starter via the
solar controller - it is a handy thing to be able to do. The
Victron units don't do that, but I would still go
Victron anyway as a better controller (IMO) than the Votronic.
If it is a feature you want to be able to do, then there are various methods but the proper way to do it is with a Trickle Charger. Be aware that most trickle chargers on the market are NOT suitable to install when you have Lithium. There is a discussion on this subject on MHF
here. The end conclusion the poster made is one I would inevitably agree with (get an AMT-12) but it is a useful discussion to read regardless.
HTH