choosing lead acid batteries for solar panels

[Alex728]

A friend of mine is converting a Bedford TK horsebox into a motorhome. Him and his missus wish to have a 24V DC system with the ability to be charged by solar panels for running their computers and some hi fi equipment.

He asked me about some lead acid batteries he saw on e-bay (Yuasa NPL series and Hawker Powersafe). I inspected the listings and some datasheets, and suggested that these were UPS or standby batteries not that suitable for the charge/discharge cycles he would be subjecting them to.

the young couple are going to work on a farm during the daytime (when the batteries would be charged) and then return to the truck in the evening which is when the power draw would occur during darkness. They do not want to use a noisy genset to either produce 230V or 13.8V to charge the batteries if possible unless in emergency..

now the question is - where is a good place to get proper deep cycle capable batteries from, and what are the types? I think Yuasa NPC is one type but are there any others? I thought maybe the brainy people on this forum are a good bunch to ask as many of you have used older bikes with lead acid batteries or are into electronics anyway..

 

[Mussels]

Are solar panels efficient enough to put more than a trickle charge into the battery anyway? Last time I looked they were a lot of money for some pretty weak promises.

 

[Alex728]

I know a few people already using them for this purpose but they are using 80 or 100W to 160W panels, not the little ones from Maplins. It certainly gives them enough power to run lights, a computer and telecoms equipment (usually one of those Chinese 3G mobile "modems") and a TV set, even during the winter..

 

[scobo]

I use 3 panels totalling 70 watts to charge my Samsung NC10 netbook among other things.
To give you some idea of what to expect, on a good day during the summer with full sun I can fully charge the netbook twice from empty. On a dull day I can charge it to about 50%.
It runs for about 6 hours on a full charge consuming around 12 watts.
I use a battery similar to this to store the power from the panels.
I have used a SLA too but found it less efficient especially when using an inverter.

 

[Footie]

For power one realy needs large solar panels, basic users who dabble in solar power are using something like two 85w panels (170w) for battery charging.
For Motorhomes and long life batteries then it's best to go for leisure batteries …. which are expensive. Their plates are thicker meaning they suffer less when heavily drained.
Heavy-duty batteries can be an alternative (I use these) but care is needed to avoid heavy discharging. A ready supply of useful low amp heavy-duty SLA batteries can be got from suppliers for mobile scooter. These are designed for heavy drain and fast charging so should stand up to a lot of punishment.
We have a campervan and use an 85amp heavy duty battery and a portable 40amp power pack, so together we have 125amp's of power, (is that right?) .... anyway it suits our needs. However it should be noted we are only running 12-volt lights and an 8-volt LCD TV and 8-volt DVD player.
I have a Maplin 5amp solar panel permanently fitted into the window of the van for keeping the batteries topped up, as the van spends most of it's time parked up. I also have two more 5amp panels which we set-up on the roof or in the windows when on site. In winter I have all three rigged up to get as much power as I can.
We camped in the New Forest recently (when it was sunny) and didn't move for three days. The three panels keep everything charged up no problem.
And the van started too

low amp heavy-duty SLA batteries
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Sealed Lead Acid Battery
12Ah Wheelchair Batteries - Wheelchair Batteries

Edit: Just noticed Tayna also do solar power batteries and panels.
Solar Power - Cheap Solar Power - Next Day Delivery

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Cougar Mountain Electric Bike 36v 200w Hub motor (Jul07)
fitted with 10 Ah LiFePo4 battery (Apr08)
Maximum range (road/hills - Cornwall) 18 miles
Maximum range (on flat) 25 miles
.